/*******************************************************************************
*
* McCode, neutron/xray ray-tracing package
*         Copyright (C) 1997-2009, All rights reserved
*         Risoe National Laboratory, Roskilde, Denmark
*         Institut Laue Langevin, Grenoble, France
*
* Runtime: share/mccode-r.c
*
* %Identification
* Written by: KN
* Date:    Aug 29, 1997
* Release: McStas X.Y/McXtrace X.Y
* Version: $Revision$
*
* Runtime system for McStas and McXtrace.
* Embedded within instrument in runtime mode.
* Contains SECTIONS:
*   MPI handling (sum, send, recv)
*   format definitions
*   I/O
*   mcdisplay support
*   random numbers
*   coordinates handling
*   vectors math (solve 2nd order, normals, randvec...)
*   parameter handling
*   signal and main handlers
*
* Usage: Automatically embbeded in the c code whenever required.
*
* $Id$
*
*******************************************************************************/

/*******************************************************************************
* The I/O format definitions and functions
*******************************************************************************/


/** Include header files to avoid implicit declarations (not allowed on LLVM) */
#include <ctype.h>
#include <sys/types.h>

// UNIX specific headers (non-Windows)
#if defined(__unix__) || defined(__APPLE__)
#include <unistd.h>
#include <sys/stat.h>
#endif


#ifndef DANSE
#ifdef MC_ANCIENT_COMPATIBILITY
int traceenabled = 0;
int defaultmain  = 0;
#endif
/* else defined directly in the McCode generated C code */

static   long mcseed                 = 0; /* seed for random generator */
#pragma acc declare create ( mcseed )
static   long mcstartdate            = 0; /* start simulation time */
static   int  mcdisable_output_files = 0; /* --no-output-files */
mcstatic int  mcgravitation          = 0; /* use gravitation flag, for PROP macros */
mcstatic int  mcdotrace              = 0; /* flag for --trace and messages for DISPLAY */
mcstatic int  mcnexus_embed_idf      = 0; /* flag to embed xml-formatted IDF file for Mantid */
#pragma acc declare create ( mcdotrace )
int      mcallowbackprop             = 0;         /* flag to enable negative/backprop */

/* OpenACC-related segmentation parameters: */
int vecsize = 128;
int numgangs = 7813;
long gpu_innerloop = 2147483647;

/* Monitor_nD list/buffer-size default */
/* Starting value may be defined using -DND_BUFFER=N */
/* Can further be controlled dynamically using --bufsiz input */
long MONND_BUFSIZ = 10000000;
#ifdef ND_BUFFER
MONND_BUFSIZ = ND_BUFFER;
#endif
 

/* Number of particle histories to simulate. */
#ifdef NEUTRONICS
mcstatic unsigned long long int mcncount             = 1;
mcstatic unsigned long long int mcrun_num            = 0;
#else
#ifdef MCDEFAULT_NCOUNT
mcstatic unsigned long long int mcncount             = MCDEFAULT_NCOUNT;
#else
mcstatic unsigned long long int mcncount             = 1000000;
#endif
#pragma acc declare create ( mcncount )
mcstatic unsigned long long int mcrun_num            = 0;
#pragma acc declare create ( mcrun_num )
#endif /* NEUTRONICS */

#else
#include "mcstas-globals.h"
#endif /* !DANSE */

#ifndef NX_COMPRESSION
#define NX_COMPRESSION NX_COMP_NONE
#endif

/* String nullification on GPU and other replacements */
#ifdef OPENACC
int noprintf() {
  return 0;
}

int str_comp(char *str1, char *str2) {
  while (*str1 && *str1 == *str2) {
    str1++;
    str2++;
  }
  return (*str1 - *str2);
}

size_t str_len(const char *s)
{
  size_t len = 0;
  if(s != NULL)
  {
    while(*s != '\0')
    {
      ++len;
      ++s;
    }
  }
  return len;
}

#endif

/* SECTION: Predefine (component) parameters ================================= */

int nans_match(double a, double b){
  return (*(uint64_t*)&a == *(uint64_t*)&b);
}
int is_unset(double x){
  return nans_match(x, UNSET);
}
int is_set(double x){
  return !nans_match(x, UNSET);
}
int is_valid(double x){
  return !isnan(x)||is_unset(x);
}
int all_unset(int n, ...){
  va_list ptr;
  va_start(ptr, n);
  int ret=1;
  for (int i=0; i<n; ++i) if(is_set(va_arg(ptr, double))) ret=0;
  va_end(ptr);
  return ret;
}
int all_set(int n, ...){
  va_list ptr;
  va_start(ptr, n);
  int ret=1;
  for (int i=0; i<n; ++i) if(is_unset(va_arg(ptr, double))) ret=0;
  va_end(ptr);
  return ret;
}
int any_unset(int n, ...){
  va_list ptr;
  va_start(ptr, n);
  int ret=0;
  for (int i=0; i<n; ++i) if(is_unset(va_arg(ptr, double))) ret=1;
  va_end(ptr);
  return ret;
}
int any_set(int n, ...){
  va_list ptr;
  va_start(ptr, n);
  int ret=0;
  for (int i=0; i<n; ++i) if(is_set(va_arg(ptr, double))) ret=1;
  va_end(ptr);
  return ret;
}


/* SECTION: Dynamic Arrays ================================================== */
IArray1d create_iarr1d(int n){
  IArray1d arr2d;
  arr2d = calloc(n, sizeof(int));
  return arr2d;
}
void destroy_iarr1d(IArray1d a){
  free(a);
}

IArray2d create_iarr2d(int nx, int ny){
  IArray2d arr2d;
  arr2d = calloc(nx, sizeof(int *));

  int *p1;
  p1 = calloc(nx*ny, sizeof(int));

  int i;
  for (i=0; i<nx; i++){
    arr2d[i] = &(p1[i*ny]);
  }
  return arr2d;
}
void destroy_iarr2d(IArray2d a){
  free(a[0]);
  free(a);
}

IArray3d create_iarr3d(int nx, int ny, int nz){
  IArray3d arr3d;
  int i, j;

  // 1d
  arr3d = calloc(nx, sizeof(int **));

  // d2
  int **p1;
  p1 = calloc(nx*ny, sizeof(int *));

  for (i=0; i<nx; i++){
    arr3d[i] = &(p1[i*ny]);
  }

  // 3d
  int *p2;
  p2 = calloc(nx*ny*nz, sizeof(int));
  for (i=0; i<nx; i++){
    for (j=0; j<ny; j++){
      arr3d[i][j] = &(p2[(i*ny+j)*nz]);
    }
  }
  return arr3d;
}

void destroy_iarr3d(IArray3d a){
  free(a[0][0]);
  free(a[0]);
  free(a);
}

DArray1d create_darr1d(int n){
  DArray1d arr2d;
  arr2d = calloc(n, sizeof(double));
  return arr2d;
}

void destroy_darr1d(DArray1d a){
  free(a);
}

DArray2d create_darr2d(int nx, int ny){
  DArray2d arr2d;
  arr2d = calloc(nx, sizeof(double *));

  double *p1;
  p1 = calloc(nx*ny, sizeof(double));

  int i;
  for (i=0; i<nx; i++){
    arr2d[i] = &(p1[i*ny]);
  }
  return arr2d;
}

void destroy_darr2d(DArray2d a){
  free(a[0]);
  free(a);
}

DArray3d create_darr3d(int nx, int ny, int nz){
  DArray3d arr3d;

  int i, j;

  // 1d
  arr3d = calloc(nx, sizeof(double **));

  // d2
  double **p1;
  p1 = calloc(nx*ny, sizeof(double *));

  for (i=0; i<nx; i++){
    arr3d[i] = &(p1[i*ny]);
  }

  // 3d
  double *p2;
  p2 = calloc(nx*ny*nz, sizeof(double));
  for (i=0; i<nx; i++){
    for (j=0; j<ny; j++){
      arr3d[i][j] = &(p2[(i*ny+j)*nz]);
    }
  }
  return arr3d;
}

void destroy_darr3d(DArray3d a){
  free(a[0][0]);
  free(a[0]);
  free(a);
}


/* SECTION: MPI handling ==================================================== */

#ifdef USE_MPI
/* MPI rank */
static int mpi_node_rank;
static int mpi_node_root = 0;


/*******************************************************************************
* mc_MPI_Reduce: Gathers arrays from MPI nodes using Reduce function.
*******************************************************************************/
int mc_MPI_Sum(double *sbuf, long count)
{
  if (!sbuf || count <= 0) return(MPI_SUCCESS); /* nothing to reduce */
  else {
    /* we must cut the buffer into blocks not exceeding the MPI max buffer size of 32000 */
    long   offset=0;
    double *rbuf=NULL;
    int    length=MPI_REDUCE_BLOCKSIZE; /* defined in mccode-r.h */
    int    i=0;
    rbuf = calloc(count, sizeof(double));
    if (!rbuf)
      exit(-fprintf(stderr, "Error: Out of memory %li (mc_MPI_Sum)\n", count*sizeof(double)));
    while (offset < count) {
      if (!length || offset+length > count-1) length=count-offset;
      else length=MPI_REDUCE_BLOCKSIZE;
      if (MPI_Allreduce((double*)(sbuf+offset), (double*)(rbuf+offset),
              length, MPI_DOUBLE, MPI_SUM, MPI_COMM_WORLD) != MPI_SUCCESS)
        return MPI_ERR_COUNT;
      offset += length;
    }

    for (i=0; i<count; i++) sbuf[i] = rbuf[i];
    free(rbuf);
  }
  return MPI_SUCCESS;
} /* mc_MPI_Sum */

/*******************************************************************************
* mc_MPI_Send: Send array to MPI node by blocks to avoid buffer limit
*******************************************************************************/
int mc_MPI_Send(void *sbuf,
                  long count, MPI_Datatype dtype,
                  int dest)
{
  int dsize;
  long offset=0;
  int  tag=1;
  int  length=MPI_REDUCE_BLOCKSIZE; /* defined in mccode-r.h */

  if (!sbuf || count <= 0) return(MPI_SUCCESS); /* nothing to send */
  MPI_Type_size(dtype, &dsize);

  while (offset < count) {
    if (offset+length > count-1) length=count-offset;
    else length=MPI_REDUCE_BLOCKSIZE;
    if (MPI_Send((void*)((char*)sbuf+offset*dsize), length, dtype, dest, tag++, MPI_COMM_WORLD) != MPI_SUCCESS)
      return MPI_ERR_COUNT;
    offset += length;
  }

  return MPI_SUCCESS;
} /* mc_MPI_Send */

/*******************************************************************************
* mc_MPI_Recv: Receives arrays from MPI nodes by blocks to avoid buffer limit
*             the buffer must have been allocated previously.
*******************************************************************************/
int mc_MPI_Recv(void *sbuf,
                  long count, MPI_Datatype dtype,
                  int source)
{
  int dsize;
  long offset=0;
  int  tag=1;
  int  length=MPI_REDUCE_BLOCKSIZE; /* defined in mccode-r.h */

  if (!sbuf || count <= 0) return(MPI_SUCCESS); /* nothing to recv */
  MPI_Type_size(dtype, &dsize);

  while (offset < count) {
    if (offset+length > count-1) length=count-offset;
    else length=MPI_REDUCE_BLOCKSIZE;
    if (MPI_Recv((void*)((char*)sbuf+offset*dsize), length, dtype, source, tag++,
            MPI_COMM_WORLD, MPI_STATUS_IGNORE) != MPI_SUCCESS)
      return MPI_ERR_COUNT;
    offset += length;
  }

  return MPI_SUCCESS;
} /* mc_MPI_Recv */

#endif /* USE_MPI */

/* SECTION: parameters handling ============================================= */

/* Instrument input parameter type handling. */
/*******************************************************************************
* mcparm_double: extract double value from 's' into 'vptr'
*******************************************************************************/
static int
mcparm_double(char *s, void *vptr)
{
  char *p;
  double *v = (double *)vptr;

  if (!s) { *v = 0; return(1); }
  *v = strtod(s, &p);
  if(*s == '\0' || (p != NULL && *p != '\0') || errno == ERANGE)
    return 0;                        /* Failed */
  else
    return 1;                        /* Success */
}

/*******************************************************************************
* mcparminfo_double: display parameter type double
*******************************************************************************/
static char *
mcparminfo_double(char *parmname)
{
  return "double";
}

/*******************************************************************************
* mcparmerror_double: display error message when failed extract double
*******************************************************************************/
static void
mcparmerror_double(char *parm, char *val)
{
  fprintf(stderr, "Error: Invalid value '%s' for floating point parameter %s (mcparmerror_double)\n",
          val, parm);
}

/*******************************************************************************
* mcparmprinter_double: convert double to string
*******************************************************************************/
static void
mcparmprinter_double(char *f, void *vptr)
{
  double *v = (double *)vptr;
  sprintf(f, "%g", *v);
}

/*******************************************************************************
* mcparm_int: extract int value from 's' into 'vptr'
*******************************************************************************/
static int
mcparm_int(char *s, void *vptr)
{
  char *p;
  int *v = (int *)vptr;
  long x;

  if (!s) { *v = 0; return(1); }
  *v = 0;
  x = strtol(s, &p, 10);
  if(x < INT_MIN || x > INT_MAX)
    return 0;                        /* Under/overflow */
  *v = x;
  if(*s == '\0' || (p != NULL && *p != '\0') || errno == ERANGE)
    return 0;                        /* Failed */
  else
    return 1;                        /* Success */
}

/*******************************************************************************
* mcparminfo_int: display parameter type int
*******************************************************************************/
static char *
mcparminfo_int(char *parmname)
{
  return "int";
}

/*******************************************************************************
* mcparmerror_int: display error message when failed extract int
*******************************************************************************/
static void
mcparmerror_int(char *parm, char *val)
{
  fprintf(stderr, "Error: Invalid value '%s' for integer parameter %s (mcparmerror_int)\n",
          val, parm);
}

/*******************************************************************************
* mcparmprinter_int: convert int to string
*******************************************************************************/
static void
mcparmprinter_int(char *f, void *vptr)
{
  int *v = (int *)vptr;
  sprintf(f, "%d", *v);
}

/*******************************************************************************
* mcparm_string: extract char* value from 's' into 'vptr' (copy)
*******************************************************************************/
static int
mcparm_string(char *s, void *vptr)
{
  char **v = (char **)vptr;
  if (!s) { *v = NULL; return(1); }
  *v = (char *)malloc(strlen(s) + 1);
  if(*v == NULL)
  {
    exit(-fprintf(stderr, "Error: Out of memory %li (mcparm_string).\n", (long)strlen(s) + 1));
  }
  strcpy(*v, s);
  return 1;                        /* Success */
}

/*******************************************************************************
* mcparminfo_string: display parameter type string
*******************************************************************************/
static char *
mcparminfo_string(char *parmname)
{
  return "string";
}

/*******************************************************************************
* mcparmerror_string: display error message when failed extract string
*******************************************************************************/
static void
mcparmerror_string(char *parm, char *val)
{
  fprintf(stderr, "Error: Invalid value '%s' for string parameter %s (mcparmerror_string)\n",
          val, parm);
}

/*******************************************************************************
* mcparmprinter_string: convert string to string (including esc chars)
*******************************************************************************/
static void
mcparmprinter_string(char *f, void *vptr)
{
  char **v = (char **)vptr;
  char *p;

  if (!*v) { *f='\0'; return; }
  strcpy(f, "");
  for(p = *v; *p != '\0'; p++)
  {
    switch(*p)
    {
      case '\n':
        strcat(f, "\\n");
        break;
      case '\r':
        strcat(f, "\\r");
        break;
      case '"':
        strcat(f, "\\\"");
        break;
      case '\\':
        strcat(f, "\\\\");
        break;
      default:
        strncat(f, p, 1);
    }
  }
  /* strcat(f, "\""); */
} /* mcparmprinter_string */

/* now we may define the parameter structure, using previous functions */
static struct
  {
    int (*getparm)(char *, void *);
    char * (*parminfo)(char *);
    void (*error)(char *, char *);
    void (*printer)(char *, void *);
} mcinputtypes[] = {
  {
    mcparm_int, mcparminfo_int, mcparmerror_int,
    mcparmprinter_int
  }, {
    mcparm_string, mcparminfo_string, mcparmerror_string,
    mcparmprinter_string
  }, {
    mcparm_string, mcparminfo_string, mcparmerror_string,
    mcparmprinter_string
  }, {
    mcparm_double, mcparminfo_double, mcparmerror_double,
    mcparmprinter_double
  }, {
    mcparm_double, mcparminfo_double, mcparmerror_double,
    mcparmprinter_double
  }
};

/*******************************************************************************
* mcestimate_error: compute sigma from N,p,p2 in Gaussian large numbers approx
*******************************************************************************/
double mcestimate_error(double N, double p1, double p2)
{
  double pmean, n1;
  if(N <= 1)
    return p1;
  pmean = p1 / N;
  n1 = N - 1;
  /* Note: underflow may cause p2 to become zero; the fabs() below guards
     against this. */
  return sqrt((N/n1)*fabs(p2 - pmean*pmean));
}

double (*mcestimate_error_p)
  (double V2, double psum, double p2sum)=mcestimate_error;

/* ========================================================================== */

/*                               MCCODE_R_IO_C                                */

/* ========================================================================== */

#ifndef MCCODE_R_IO_C
#define MCCODE_R_IO_C "$Revision$"

/* SECTION: file i/o handling ================================================ */

#ifndef HAVE_STRCASESTR
// from msysgit: https://code.google.com/p/msysgit/source/browse/compat/strcasestr.c
char *strcasestr(const char *haystack, const char *needle)
{
  int nlen = strlen(needle);
  int hlen = strlen(haystack) - nlen + 1;
  int i;

  for (i = 0; i < hlen; i++) {
    int j;
    for (j = 0; j < nlen; j++) {
            unsigned char c1 = haystack[i+j];
            unsigned char c2 = needle[j];
            if (toupper(c1) != toupper(c2))
                    goto next;
    }
    return (char *) haystack + i;
  next:
    ;
  }
  return NULL;
}


#endif
#ifndef HAVE_STRCASECMP
int strcasecmp( const char *s1, const char *s2 )
{
  int c1, c2;
  do {
    c1 = tolower( (unsigned char) *s1++ );
    c2 = tolower( (unsigned char) *s2++ );
  } while (c1 == c2 && c1 != 0);
  return c2 > c1 ? -1 : c1 > c2;
}
#endif

#ifndef STRACPY
/* this is a replacement to strncpy, but ensures that the copy ends with NULL */
/* http://stracpy.blogspot.fr/2011/04/stracpy-strncpy-replacement.html */
#define STRACPY
char *stracpy(char *destination, const char *source, size_t amount)
{
        if (!destination || !source || !amount) return(NULL);
        while(amount--)
          if((*destination++ = *source++) == '\0') break;
        *destination = '\0';
        return destination;
}
#endif

/*******************************************************************************
* mcfull_file: allocates a full file name=dirname+file. Catenate extension if missing.
*******************************************************************************/
char *mcfull_file(char *name, char *ext)
{
  int   dirlen=0;
  char *mem   =NULL;

  dirlen = dirname ? strlen(dirname) : 0;
  mem = (char*)malloc(dirlen + strlen(name) + CHAR_BUF_LENGTH);
  if(!mem) {
    exit(-fprintf(stderr, "Error: Out of memory %li (mcfull_file)\n", (long)(dirlen + strlen(name) + 256)));
  }
  strcpy(mem, "");

  /* prepend directory name to path if name does not contain a path */
  if (dirlen > 0 && !strchr(name, MC_PATHSEP_C)) {
    strcat(mem, dirname);
    strcat(mem, MC_PATHSEP_S);
  } /* dirlen */

  strcat(mem, name);
  if (!strchr(name, '.') && ext && strlen(ext))
  { /* add extension if not in file name already */
    strcat(mem, ".");
    strcat(mem, ext);
  }
  return(mem);
} /* mcfull_file */

/*******************************************************************************
* mcnew_file: opens a new file within dirname if non NULL
*             the file is opened in "a" (append, create if does not exist)
*             the extension 'ext' is added if the file name does not include one.
*             the last argument is set to 0 if file did not exist, else to 1.
*******************************************************************************/
FILE *mcnew_file(char *name, char *ext, int *exists)
{
  char *mem;
  FILE *file=NULL;

  if (!name || strlen(name) == 0 || mcdisable_output_files) return(NULL);

  mem  = mcfull_file(name, ext); /* create dirname/name.ext */

  /* check for existence */
  file = fopen(mem, "r"); /* for reading -> fails if does not exist */
  if (file) {
    fclose(file);
    *exists=1;
  } else
    *exists=0;

  /* open the file for writing/appending */
#ifdef USE_NEXUS
  if (mcformat && strcasestr(mcformat, "NeXus")) {
    /* NXhandle nxhandle is defined in the .h with USE_NEXUS */
    NXaccess mode = (*exists ? NXACC_CREATE5 | NXACC_RDWR : NXACC_CREATE5);

    if (NXopen(mem, mode, &nxhandle) != NX_OK)
      file = NULL;
    else
      file = (FILE*)&nxhandle; /* to make it non NULL */
  } else
#endif
    file = fopen(mem, "a+");

  if(!file)
    fprintf(stderr, "Warning: could not open output file '%s' for %s (mcnew_file)\n",
      mem, *exists ? "append" : "create");
  free(mem);

  return file;
} /* mcnew_file */

/*******************************************************************************
* mcdetector_statistics: compute detector statistics, error bars, [x I I_err N] 1D
* RETURN:            updated detector structure
* Used by: detector_import
*******************************************************************************/
MCDETECTOR mcdetector_statistics(
  MCDETECTOR detector)
{

  if (!detector.p1 || !detector.m)
    return(detector);

  /* compute statistics and update MCDETECTOR structure ===================== */
  double sum_z  = 0, min_z  = 0, max_z  = 0;
  double fmon_x =0,  smon_x = 0, fmon_y =0, smon_y=0, mean_z=0;
  double Nsum=0, P2sum=0;

  double sum_xz = 0, sum_yz = 0, sum_x = 0, sum_y = 0, sum_x2z = 0, sum_y2z = 0;
  int    i,j;
  char   hasnan=0, hasinf=0;
  char   israw = ((char*)strcasestr(detector.format,"raw") != NULL);
  double *this_p1=NULL; /* new 1D McCode array [x I E N]. Freed after writing data */

  /* if McCode/PGPLOT and rank==1 we create a new m*4 data block=[x I E N] */
  if (detector.rank == 1 && strcasestr(detector.format,"McCode")) {
    this_p1 = (double *)calloc(detector.m*detector.n*detector.p*4, sizeof(double));
    if (!this_p1)
      exit(-fprintf(stderr, "Error: Out of memory creating %li 1D " MCCODE_STRING " data set for file '%s' (detector_import)\n",
        detector.m*detector.n*detector.p*4*sizeof(double*), detector.filename));
  }

  max_z = min_z = detector.p1[0];

  /* compute sum and moments (not for lists) */
  if (!strcasestr(detector.format,"list") && detector.m)
  for(j = 0; j < detector.n*detector.p; j++)
  {
    for(i = 0; i < detector.m; i++)
    {
      double x,y,z;
      double N, E;
      long   index= !detector.istransposed ? i*detector.n*detector.p + j : i+j*detector.m;
      char   hasnaninf=0;

      if (detector.m)
        x = detector.xmin + (i + 0.5)/detector.m*(detector.xmax - detector.xmin);
      else x = 0;
      if (detector.n && detector.p)
        y = detector.ymin + (j + 0.5)/detector.n/detector.p*(detector.ymax - detector.ymin);
      else y = 0;
      z = detector.p1[index];
      N = detector.p0 ? detector.p0[index] : 1;
      E = detector.p2 ? detector.p2[index] : 0;
      if (detector.p2 && !israw)
        detector.p2[index] = (*mcestimate_error_p)(detector.p0[index],detector.p1[index],detector.p2[index]); /* set sigma */

      if (detector.rank == 1 && this_p1 && strcasestr(detector.format,"McCode")) {
        /* fill-in 1D McCode array [x I E N] */
        this_p1[index*4]   = x;
        this_p1[index*4+1] = z;
        this_p1[index*4+2] = detector.p2 ? detector.p2[index] : 0;
        this_p1[index*4+3] = N;
      }

      if (isnan(z) || isnan(E) || isnan(N)) hasnaninf=hasnan=1;
      if (isinf(z) || isinf(E) || isinf(N)) hasnaninf=hasinf=1;

      /* compute stats integrals */
      if (!hasnaninf) {
        sum_xz += x*z;
        sum_yz += y*z;
        sum_x  += x;
        sum_y  += y;
        sum_z  += z;
        sum_x2z += x*x*z;
        sum_y2z += y*y*z;
        if (z > max_z) max_z = z;
        if (z < min_z) min_z = z;

        Nsum += N;
        P2sum += E;
      }

    }
  } /* for j */

  /* compute 1st and 2nd moments. For lists, sum_z=0 so this is skipped. */
  if (sum_z && detector.n*detector.m*detector.p)
  {
    fmon_x = sum_xz/sum_z;
    fmon_y = sum_yz/sum_z;
    smon_x = sum_x2z/sum_z-fmon_x*fmon_x; smon_x = smon_x > 0 ? sqrt(smon_x) : 0;
    smon_y = sum_y2z/sum_z-fmon_y*fmon_y; smon_y = smon_y > 0 ? sqrt(smon_y) : 0;
    mean_z = sum_z/detector.n/detector.m/detector.p;
  }
  /* store statistics into detector */
  detector.intensity = sum_z;
  detector.error     = Nsum ? (*mcestimate_error_p)(Nsum, sum_z, P2sum) : 0;
  detector.events    = Nsum;
  detector.min       = min_z;
  detector.max       = max_z;
  detector.mean      = mean_z;
  detector.centerX   = fmon_x;
  detector.halfwidthX= smon_x;
  detector.centerY   = fmon_y;
  detector.halfwidthY= smon_y;

  /* if McCode/PGPLOT and rank==1 replace p1 with new m*4 1D McCode and clear others */
  if (detector.rank == 1 && this_p1 && strcasestr(detector.format,"McCode")) {

    detector.p1 = this_p1;
    detector.n  = detector.m; detector.m  = 4;
    detector.p0 = detector.p2 = NULL;
    detector.istransposed = 1;
  }

  if (detector.n*detector.m*detector.p > 1)
    snprintf(detector.signal, CHAR_BUF_LENGTH,
      "Min=%g; Max=%g; Mean=%g;", detector.min, detector.max, detector.mean);
  else
    strcpy(detector.signal, "None");
  snprintf(detector.values, CHAR_BUF_LENGTH,
    "%g %g %g", detector.intensity, detector.error, detector.events);

  switch (detector.rank) {
    case 1:  snprintf(detector.statistics, CHAR_BUF_LENGTH, "X0=%g; dX=%g;",
      detector.centerX, detector.halfwidthX); break;
    case 2:
    case 3:  snprintf(detector.statistics, CHAR_BUF_LENGTH, "X0=%g; dX=%g; Y0=%g; dY=%g;",
      detector.centerX, detector.halfwidthX, detector.centerY, detector.halfwidthY);
      break;
    default: strcpy(detector.statistics, "None");
  }

  if (hasnan)
    printf("WARNING: Nan detected in component/file %s %s\n",
      detector.component, strlen(detector.filename) ? detector.filename : "");
  if (hasinf)
    printf("WARNING: Inf detected in component/file %s %s\n",
      detector.component, strlen(detector.filename) ? detector.filename : "");

  return(detector);

} /* mcdetector_statistics */

/*******************************************************************************
* detector_import: build detector structure, merge non-lists from MPI
*                    compute basic stat, write "Detector:" line
* RETURN:            detector structure. Invalid data if detector.p1 == NULL
*                    Invalid detector sets m=0 and filename=""
*                    Simulation data  sets m=0 and filename=siminfo_name
* This function is equivalent to the old 'mcdetector_out', returning a structure
*******************************************************************************/
MCDETECTOR detector_import(
  char *format,
  char *component, char *title,
  long m, long n,  long p,
  char *xlabel, char *ylabel, char *zlabel,
  char *xvar, char *yvar, char *zvar,
  double x1, double x2, double y1, double y2, double z1, double z2,
  char *filename,
  double *p0, double *p1, double *p2,
  Coords position, Rotation rotation)
{
  time_t t;       /* for detector.date */
  long   date_l;  /* date as a long number */
  char   istransposed=0;
  char   c[CHAR_BUF_LENGTH]; /* temp var for signal label */

  MCDETECTOR detector;

  /* build MCDETECTOR structure ============================================= */
  /* make sure we do not have NULL for char fields */

  /* these also apply to simfile */
  strncpy (detector.filename,  filename ? filename : "",        CHAR_BUF_LENGTH);
  strncpy (detector.format,    format   ? format   : "McCode" , CHAR_BUF_LENGTH);
  /* add extension if missing */
  if (strlen(detector.filename) && !strchr(detector.filename, '.'))
  { /* add extension if not in file name already */
    strcat(detector.filename, ".dat");
  }
  strncpy (detector.component, component ? component : MCCODE_STRING " component", CHAR_BUF_LENGTH);

  snprintf(detector.instrument, CHAR_BUF_LENGTH, "%s (%s)", instrument_name, instrument_source);
  snprintf(detector.user, CHAR_BUF_LENGTH,      "%s on %s",
        getenv("USER") ? getenv("USER") : MCCODE_NAME,
        getenv("HOST") ? getenv("HOST") : "localhost");
  time(&t);         /* get current write time */
  date_l = (long)t; /* same but as a long */
  snprintf(detector.date, CHAR_BUF_LENGTH, "%s", ctime(&t));
  if (strlen(detector.date))   detector.date[strlen(detector.date)-1] = '\0'; /* remove last \n in date */
  detector.date_l = date_l;

  if (!mcget_run_num() || mcget_run_num() >= mcget_ncount())
    snprintf(detector.ncount, CHAR_BUF_LENGTH, "%llu", mcget_ncount()
#ifdef USE_MPI
*mpi_node_count
#endif
  );
  else
    snprintf(detector.ncount, CHAR_BUF_LENGTH, "%g/%g", (double)mcget_run_num(), (double)mcget_ncount());

  detector.p0         = p0;
  detector.p1         = p1;
  detector.p2         = p2;

  /* handle transposition (not for NeXus) */
  if (!strcasestr(detector.format, "NeXus")) {
    if (m<0 || n<0 || p<0)             istransposed = !istransposed;
    if (strcasestr(detector.format, "transpose")) istransposed = !istransposed;
    if (istransposed) { /* do the swap once for all */
      long i=m; m=n; n=i;
    }
  }

  m=labs(m); n=labs(n); p=labs(p); /* make sure dimensions are positive */
  detector.istransposed = istransposed;

  /* determine detector rank (dimensionality) */
  if (!m || !n || !p || !p1) detector.rank = 4; /* invalid: exit with m=0 filename="" */
  else if (m*n*p == 1)       detector.rank = 0; /* 0D */
  else if (n == 1 || m == 1) detector.rank = 1; /* 1D */
  else if (p == 1)           detector.rank = 2; /* 2D */
  else                       detector.rank = 3; /* 3D */

  /* from rank, set type */
  switch (detector.rank) {
    case 0:  strcpy(detector.type,  "array_0d"); m=n=p=1; break;
    case 1:  snprintf(detector.type, CHAR_BUF_LENGTH, "array_1d(%ld)", m*n*p); m *= n*p; n=p=1; break;
    case 2:  snprintf(detector.type, CHAR_BUF_LENGTH, "array_2d(%ld, %ld)", m, n*p); n *= p; p=1; break;
    case 3:  snprintf(detector.type, CHAR_BUF_LENGTH, "array_3d(%ld, %ld, %ld)", m, n, p); break;
    default: m=0; strcpy(detector.type, ""); strcpy(detector.filename, "");/* invalid */
  }

  detector.m    = m;
  detector.n    = n;
  detector.p    = p;

  /* these only apply to detector files ===================================== */

  detector.Position[0]=position.x;
  detector.Position[1]=position.y;
  detector.Position[2]=position.z;
  rot_copy(detector.Rotation,rotation);
  snprintf(detector.position, CHAR_BUF_LENGTH, "%g %g %g", position.x, position.y, position.z);
  /* may also store actual detector orientation in the future */

  strncpy(detector.title,      title && strlen(title) ? title : component,       CHAR_BUF_LENGTH);
  strncpy(detector.xlabel,     xlabel && strlen(xlabel) ? xlabel : "X", CHAR_BUF_LENGTH); /* axis labels */
  strncpy(detector.ylabel,     ylabel && strlen(ylabel) ? ylabel : "Y", CHAR_BUF_LENGTH);
  strncpy(detector.zlabel,     zlabel && strlen(zlabel) ? zlabel : "Z", CHAR_BUF_LENGTH);
  strncpy(detector.xvar,       xvar && strlen(xvar) ? xvar :       "x", CHAR_BUF_LENGTH); /* axis variables */
  strncpy(detector.yvar,       yvar && strlen(yvar) ? yvar :       detector.xvar, CHAR_BUF_LENGTH);
  strncpy(detector.zvar,       zvar && strlen(zvar) ? zvar :       detector.yvar, CHAR_BUF_LENGTH);

  /* set "variables" as e.g. "I I_err N" */
  strcpy(c, "I ");
  if (strlen(detector.zvar))      strncpy(c, detector.zvar,32);
  else if (strlen(detector.yvar)) strncpy(c, detector.yvar,32);
  else if (strlen(detector.xvar)) strncpy(c, detector.xvar,32);

  if (detector.rank == 1)
    snprintf(detector.variables, CHAR_BUF_LENGTH, "%s %s %s_err N", detector.xvar, c, c);
  else
    snprintf(detector.variables, CHAR_BUF_LENGTH, "%s %s_err N", c, c);

  /* limits */
  detector.xmin = x1;
  detector.xmax = x2;
  detector.ymin = y1;
  detector.ymax = y2;
  detector.zmin = z1;
  detector.zmax = z2;
  if (abs(detector.rank) == 1)
    snprintf(detector.limits, CHAR_BUF_LENGTH, "%g %g", x1, x2);
  else if (detector.rank == 2)
    snprintf(detector.limits, CHAR_BUF_LENGTH, "%g %g %g %g", x1, x2, y1, y2);
  else
    snprintf(detector.limits, CHAR_BUF_LENGTH, "%g %g %g %g %g %g", x1, x2, y1, y2, z1, z2);

  /* if MPI and nodes_nb > 1: reduce data sets when using MPI =============== */
#ifdef USE_MPI
  if (!strcasestr(detector.format,"list") && mpi_node_count > 1 && m) {
    /* we save additive data: reduce everything into mpi_node_root */
    if (p0) mc_MPI_Sum(p0, m*n*p);
    if (p1) mc_MPI_Sum(p1, m*n*p);
    if (p2) mc_MPI_Sum(p2, m*n*p);
    if (!p0) {  /* additive signal must be then divided by the number of nodes */
      int i;
      for (i=0; i<m*n*p; i++) {
        p1[i] /= mpi_node_count;
        if (p2) p2[i] /= mpi_node_count;
      }
    }
  }
#endif /* USE_MPI */

  /* compute statistics, Nsum, intensity, Error bars */
  detector = mcdetector_statistics(detector);

#ifdef USE_MPI
  /* slaves are done */
  if(mpi_node_rank != mpi_node_root) {
    return detector;
  }
#endif

  /* output "Detector:" line ================================================ */
  /* when this is a detector written by a component (not the SAVE from instrument),
     not an event lists */
  if (!m) return(detector);
  if (!strcasestr(detector.format,"list")) {
    if (!strcmp(detector.component, instrument_name)) {
      if (strlen(detector.filename))  /* we name it from its filename, or from its title */
        strncpy(c, detector.filename, CHAR_BUF_LENGTH);
      else
        snprintf(c, CHAR_BUF_LENGTH, "%s", instrument_name);
    } else
      strncpy(c, detector.component, CHAR_BUF_LENGTH);  /* usual detectors written by components */

    printf("Detector: %s_I=%g %s_ERR=%g %s_N=%g",
           c, detector.intensity,
           c, detector.error,
           c, detector.events);
    printf(" \"%s\"\n", strlen(detector.filename) ? detector.filename : detector.component);
  }


  return(detector);
} /* detector_import */

/* end MCDETECTOR import section ============================================ */

















/* ========================================================================== */

/*                               ASCII output                                 */
/*     The SIM file is YAML based, the data files have '#' headers            */

/* ========================================================================== */


/*******************************************************************************
* mcinfo_out: output instrument tags/info (only in SIM)
* Used in: siminfo_init (ascii), mcinfo(stdout)
*******************************************************************************/
static void mcinfo_out(char *pre, FILE *f)
{
  char Parameters[CHAR_BUF_LENGTH] = "";
  int  i;

  if (!f || mcdisable_output_files) return;

  /* create parameter string ================================================ */
  for(i = 0; i < numipar; i++)
  {
    char ThisParam[CHAR_BUF_LENGTH];
    if (strlen(mcinputtable[i].name) > CHAR_BUF_LENGTH) break;
    snprintf(ThisParam, CHAR_BUF_LENGTH, " %s(%s)", mcinputtable[i].name,
            (*mcinputtypes[mcinputtable[i].type].parminfo)
                (mcinputtable[i].name));
    if (strlen(Parameters) + strlen(ThisParam) + 1 >= CHAR_BUF_LENGTH) break;
    strcat(Parameters, ThisParam);
  }

  /* output data ============================================================ */
  if (f != stdout)
    fprintf(f, "%sFile: %s%c%s\n",    pre, dirname, MC_PATHSEP_C, siminfo_name);
  else
    fprintf(f, "%sCreator: %s\n",     pre, MCCODE_STRING);

  fprintf(f, "%sSource: %s\n",   pre, instrument_source);
  fprintf(f, "%sParameters: %s\n",    pre, Parameters);

  fprintf(f, "%sTrace_enabled: %s\n", pre, traceenabled ? "yes" : "no");
  fprintf(f, "%sDefault_main: %s\n",  pre, defaultmain ?  "yes" : "no");
#ifdef MC_EMBEDDED_RUNTIME
  fprintf(f, "%sEmbedded_runtime: %s\n", pre, "yes");
#else
  fprintf(f, "%sEmbedded_runtime: %s\n", pre, "no");
#endif

  fflush(f);
} /* mcinfo_out */

/*******************************************************************************
* mcruninfo_out: output simulation tags/info (both in SIM and data files)
* Used in: siminfo_init (ascii case), mcdetector_out_xD_ascii
*******************************************************************************/
static void mcruninfo_out(char *pre, FILE *f)
{
  int i;
  char Parameters[CHAR_BUF_LENGTH];

  if (!f || mcdisable_output_files) return;

  fprintf(f, "%sFormat: %s%s\n",      pre,
    mcformat && strlen(mcformat) ? mcformat : MCCODE_NAME,
    mcformat && strcasestr(mcformat,"McCode") ? " with text headers" : "");
  fprintf(f, "%sURL: %s\n",         pre, "http://www.mccode.org");
  fprintf(f, "%sCreator: %s\n",     pre, MCCODE_STRING);
  fprintf(f, "%sInstrument: %s\n", pre, instrument_source);
  fprintf(f, "%sNcount: %llu\n",        pre, mcget_ncount());
  fprintf(f, "%sTrace: %s\n",       pre, mcdotrace ? "yes" : "no");
  fprintf(f, "%sGravitation: %s\n", pre, mcgravitation ? "yes" : "no");
  snprintf(Parameters, CHAR_BUF_LENGTH, "%ld", mcseed);
  fprintf(f, "%sSeed: %s\n",        pre, Parameters);
  fprintf(f, "%sDirectory: %s\n",        pre, dirname ? dirname : ".");
#ifdef USE_MPI
  if (mpi_node_count > 1)
    fprintf(f, "%sNodes: %i\n",        pre, mpi_node_count);
#endif

  // TODO Consider replacing this by a a call to `mcparameterinfo_out(pre+"Param: ", f)`
  /* output parameter string ================================================ */
  for(i = 0; i < numipar; i++) {
      if (mcinputtable[i].par){
	/* Parameters with a default value */
	if(mcinputtable[i].val && strlen(mcinputtable[i].val)){
	  (*mcinputtypes[mcinputtable[i].type].printer)(Parameters, mcinputtable[i].par);
	  fprintf(f, "%sParam: %s=%s\n", pre, mcinputtable[i].name, Parameters);
        /* ... and those without */
	}else{
	  fprintf(f, "%sParam: %s=NULL\n", pre, mcinputtable[i].name);
	}
      }
  }
  fflush(f);
} /* mcruninfo_out */

/*******************************************************************************
 * @brief Print parameter information to the specified file
 * @param pre any beginning-of-line padding
 * @param f the output file
 */
static void mcparameterinfo_out(char * pre, FILE *f){
  if (!f || mcdisable_output_files) return;

  unsigned int nchar = 4;
  for (int i=0; i < numipar; ++i){
    if (mcinputtable[i].par && mcinputtable[i].val && strlen(mcinputtable[i].val) > nchar)
      nchar = strlen(mcinputtable[i].val);
  }
  char * buffer = calloc(nchar+1, sizeof(char));

  if (!buffer) {
    exit(1);
  }

  for (int i=0; i < numipar; ++i) {
    if (mcinputtable[i].par) {
      char * name = mcinputtable[i].name;
      if (mcinputtable[i].val && strlen(mcinputtable[i].val)) {
        mcinputtypes[mcinputtable[i].type].printer(buffer, mcinputtable[i].par);
      } else {
        strcpy(buffer, "NULL");
      }
      if (strlen(mcinputtable[i].unit)){
        //fprintf(f, "%s%s %s (\"%s\") = %s\n", pre, mcinputtypes[mcinputtable[i].type].parminfo(name), name, mcinputtable[i].unit, buffer);
        fprintf(f, "%s%s %s/\"%s\" = %s\n", pre, mcinputtypes[mcinputtable[i].type].parminfo(name), name, mcinputtable[i].unit, buffer);
      } else {
        fprintf(f, "%s%s %s = %s\n", pre, mcinputtypes[mcinputtable[i].type].parminfo(name), name, buffer);
      }
    }
  }

  free(buffer);
}

/*******************************************************************************
* siminfo_out:    wrapper to fprintf(siminfo_file)
*******************************************************************************/
void siminfo_out(char *format, ...)
{
  va_list ap;

  if(siminfo_file && !mcdisable_output_files)
  {
    va_start(ap, format);
    vfprintf(siminfo_file, format, ap);
    va_end(ap);
  }
} /* siminfo_out */


/*******************************************************************************
* mcdatainfo_out: output detector header
*   mcdatainfo_out(prefix, file_handle, detector) writes info to data file
*******************************************************************************/
static void
mcdatainfo_out(char *pre, FILE *f, MCDETECTOR detector)
{
  if (!f || !detector.m || mcdisable_output_files) return;

  /* output data ============================================================ */
  fprintf(f, "%sDate: %s (%li)\n",       pre, detector.date, detector.date_l);
  fprintf(f, "%stype: %s\n",       pre, detector.type);
  fprintf(f, "%sSource: %s\n",     pre, detector.instrument);
  fprintf(f, "%scomponent: %s\n",  pre, detector.component);
  fprintf(f, "%sposition: %s\n",   pre, detector.position);

  fprintf(f, "%stitle: %s\n",      pre, detector.title);
  fprintf(f, !mcget_run_num() || mcget_run_num() >= mcget_ncount() ?
             "%sNcount: %s\n" :
             "%sratio: %s\n",  pre, detector.ncount);

  if (strlen(detector.filename)) {
    fprintf(f, "%sfilename: %s\n", pre, detector.filename);
  }

  fprintf(f, "%sstatistics: %s\n", pre, detector.statistics);
  fprintf(f, "%ssignal: %s\n",     pre, detector.signal);
  fprintf(f, "%svalues: %s\n",     pre, detector.values);

  if (detector.rank >= 1)
  {
    fprintf(f, "%sxvar: %s\n",     pre, detector.xvar);
    fprintf(f, "%syvar: %s\n",     pre, detector.yvar);
    fprintf(f, "%sxlabel: %s\n",   pre, detector.xlabel);
    fprintf(f, "%sylabel: %s\n",   pre, detector.ylabel);
    if (detector.rank > 1) {
      fprintf(f, "%szvar: %s\n",   pre, detector.zvar);
      fprintf(f, "%szlabel: %s\n", pre, detector.zlabel);
    }
  }

  fprintf(f,
    abs(detector.rank)==1 ?
             "%sxlimits: %s\n" :
             "%sxylimits: %s\n", pre, detector.limits);
  fprintf(f, "%svariables: %s\n", pre,
    strcasestr(detector.format, "list") ? detector.ylabel : detector.variables);

  fflush(f);

} /* mcdatainfo_out */

/* mcdetector_out_array_ascii: output a single array to a file
 *   m: columns
 *   n: rows
 *   p: array
 *   f: file handle (already opened)
 */
static void mcdetector_out_array_ascii(long m, long n, double *p, FILE *f, char istransposed)
{
  if(f)
  {
    int i,j;
    for(j = 0; j < n; j++)
    {
      for(i = 0; i < m; i++)
      {
          fprintf(f, "%.10g ", p[!istransposed ? i*n + j : j*m+i]);
      }
      fprintf(f,"\n");
    }
  }
} /* mcdetector_out_array_ascii */

/*******************************************************************************
* mcdetector_out_0D_ascii: called by mcdetector_out_0D for ascii output
*******************************************************************************/
MCDETECTOR mcdetector_out_0D_ascii(MCDETECTOR detector)
{
  int exists=0;
  FILE *outfile = NULL;

  /* Write data set information to simulation description file. */
  MPI_MASTER(
    siminfo_out("\nbegin data\n"); // detector.component
    mcdatainfo_out("  ", siminfo_file, detector);
    siminfo_out("end data\n");
    /* Don't write if filename is NULL: mcnew_file handles this (return NULL) */
    outfile = mcnew_file(detector.component, "dat", &exists);
    if(outfile)
    {
      /* write data file header and entry in simulation description file */
      mcruninfo_out( "# ", outfile);
      mcdatainfo_out("# ", outfile, detector);
      /* write I I_err N */
      fprintf(outfile, "%g %g %g\n",
        detector.intensity, detector.error, detector.events);
      fclose(outfile);
    }
  ); /* MPI_MASTER */
  return(detector);
} /* mcdetector_out_0D_ascii */

/*******************************************************************************
* mcdetector_out_1D_ascii: called by mcdetector_out_1D for ascii output
*******************************************************************************/
MCDETECTOR mcdetector_out_1D_ascii(MCDETECTOR detector)
{
  int exists=0;
  FILE *outfile = NULL;

  MPI_MASTER(
    /* Write data set information to simulation description file. */
    siminfo_out("\nbegin data\n"); // detector.filename
    mcdatainfo_out("  ", siminfo_file, detector);
    siminfo_out("end data\n");
    /* Loop over array elements, writing to file. */
    /* Don't write if filename is NULL: mcnew_file handles this (return NULL) */
    outfile = mcnew_file(detector.filename, "dat", &exists);
    if(outfile)
    {
      /* write data file header and entry in simulation description file */
      mcruninfo_out( "# ", outfile);
      mcdatainfo_out("# ", outfile, detector);
      /* output the 1D array columns */
      mcdetector_out_array_ascii(detector.m, detector.n, detector.p1, outfile, detector.istransposed);

      fclose(outfile);
    }
  ); /* MPI_MASTER */
  return(detector);

}  /* mcdetector_out_1D_ascii */

/*******************************************************************************
* mcdetector_out_2D_ascii: called by mcdetector_out_2D for ascii output
*******************************************************************************/
MCDETECTOR mcdetector_out_2D_ascii(MCDETECTOR detector)
{
  int exists=0;
  FILE *outfile = NULL;

  MPI_MASTER(
    /* Loop over array elements, writing to file. */
    /* Don't write if filename is NULL: mcnew_file handles this (return NULL) */
    outfile = mcnew_file(detector.filename, "dat", &exists);
    if(outfile)
    {
      /* write header only if file has just been created (not appending) */
      if (!exists) {
        /* Write data set information to simulation description file. */
        siminfo_out("\nbegin data\n"); // detector.filename
        mcdatainfo_out("  ", siminfo_file, detector);
        siminfo_out("end data\n");

        mcruninfo_out( "# ", outfile);
        mcdatainfo_out("# ", outfile,   detector);
        fprintf(outfile, "# Data [%s/%s] %s:\n", detector.component, detector.filename, detector.zvar);
      }
      mcdetector_out_array_ascii(detector.m, detector.n*detector.p, detector.p1,
        outfile, detector.istransposed);
      if (detector.p2) {
        fprintf(outfile, "# Errors [%s/%s] %s_err:\n", detector.component, detector.filename, detector.zvar);
        mcdetector_out_array_ascii(detector.m, detector.n*detector.p, detector.p2,
          outfile, detector.istransposed);
      }
      if (detector.p0) {
        fprintf(outfile, "# Events [%s/%s] N:\n", detector.component, detector.filename);
        mcdetector_out_array_ascii(detector.m, detector.n*detector.p, detector.p0,
          outfile, detector.istransposed);
      }
      fclose(outfile);

      if (!exists) {
        if (strcasestr(detector.format, "list"))
          printf("Events:   \"%s\"\n",
            strlen(detector.filename) ? detector.filename : detector.component);
      }
    } /* if outfile */
  ); /* MPI_MASTER */
#ifdef USE_MPI
  if (strcasestr(detector.format, "list") && mpi_node_count > 1) {
    int node_i=0;
    /* loop along MPI nodes to write sequentially */
    for(node_i=0; node_i<mpi_node_count; node_i++) {
      /* MPI: slaves wait for the master to write its block, then append theirs */
      MPI_Barrier(MPI_COMM_WORLD);
      if (node_i != mpi_node_root && node_i == mpi_node_rank) {
        if(strlen(detector.filename) && !mcdisable_output_files)	/* Don't write if filename is NULL */
          outfile = mcnew_file(detector.filename, "dat", &exists);
        if (!exists)
          fprintf(stderr, "Warning: [MPI node %i] file '%s' does not exist yet, "
                          "MASTER should have opened it before.\n",
            mpi_node_rank, detector.filename);
        if(outfile) {
          mcdetector_out_array_ascii(detector.m, detector.n*detector.p, detector.p1,
            outfile, detector.istransposed);
          fclose(outfile);
        }
      }
    }
  } /* if strcasestr list */
#endif
  return(detector);
} /* mcdetector_out_2D_ascii */

/*******************************************************************************
* strcpy_valid: makes a valid string for variable names.
*   copy 'original' into 'valid', replacing invalid characters by '_'
*   char arrays must be pre-allocated
*******************************************************************************/
static char *strcpy_valid(char *valid, char *original)
{
  long i;
  int  n=CHAR_BUF_LENGTH; /* max length of valid names */

  if (original == NULL || !strlen(original)) return(NULL);

  if (n > strlen(original)) n = strlen(original);
  else original += strlen(original)-n;
  strncpy(valid, original, n);

  for (i=0; i < n; i++)
  {
    if ( (valid[i] > 122)
      || (valid[i] < 32)
      || (strchr("!\"#$%&'()*+,-.:;<=>?@[\\]^`/ \n\r\t", valid[i]) != NULL) )
    {
      if (i) valid[i] = '_'; else valid[i] = 'm';
    }
  }
  valid[i] = '\0';

  return(valid);
} /* strcpy_valid */

/* end ascii output section ================================================= */







#ifdef USE_NEXUS

/* ========================================================================== */

/*                               NeXus output                                 */

/* ========================================================================== */

#define nxprintf(...)    nxstr('d', __VA_ARGS__)
#define nxprintattr(...) nxstr('a', __VA_ARGS__)

/*******************************************************************************
* nxstr: output a tag=value data set (char) in NeXus/current group
*   when 'format' is larger that 1024 chars it is used as value for the 'tag'
*   else the value is assembled with format and following arguments.
*   type='d' -> data set
*        'a' -> attribute for current data set
*******************************************************************************/
static int nxstr(char type, NXhandle *f, char *tag, char *format, ...)
{
  va_list ap;
  char value[CHAR_BUF_LENGTH];
  int  i;
  int  ret=NX_OK;

  if (!tag || !format || !strlen(tag) || !strlen(format)) return(NX_OK);

  /* assemble the value string */
  if (strlen(format) < CHAR_BUF_LENGTH) {
    va_start(ap, format);
    ret = vsnprintf(value, CHAR_BUF_LENGTH, format, ap);
    va_end(ap);

    i = strlen(value);
  } else {
    i = strlen(format);
  }

  if (type == 'd') {
    /* open/put/close data set */
    if (NXmakedata (f, tag, NX_CHAR, 1, &i) != NX_OK) return(NX_ERROR);
    NXopendata (f, tag);
    if (strlen(format) < CHAR_BUF_LENGTH)
      ret = NXputdata  (f, value);
    else
      ret = NXputdata  (f, format);
    NXclosedata(f);
  } else {
    if (strlen(format) < CHAR_BUF_LENGTH)
      ret = NXputattr  (f, tag, value, strlen(value), NX_CHAR);
    else
      ret = NXputattr  (f, tag, format, strlen(format), NX_CHAR);
  }

  return(ret);

} /* nxstr */

/*******************************************************************************
* mcinfo_readfile: read a full file into a string buffer which is allocated
*   Think to free the buffer after use.
* Used in: mcinfo_out_nexus (nexus)
*******************************************************************************/
char *mcinfo_readfile(char *filename)
{
  FILE *f = fopen(filename, "rb");
  if (!f) return(NULL);
  fseek(f, 0, SEEK_END);
  long fsize = ftell(f);
  rewind(f);
  char *string = malloc(fsize + 1);
  if (string) {
    int n = fread(string, fsize, 1, f);
    fclose(f);

    string[fsize] = 0;
  }
  return(string);
}

/*******************************************************************************
* mcinfo_out: output instrument/simulation groups in NeXus file
* Used in: siminfo_init (nexus)
*******************************************************************************/
static void mcinfo_out_nexus(NXhandle f)
{
  FILE  *fid;     /* for intrument source code/C/IDF */
  char  *buffer=NULL;
  time_t t     =time(NULL); /* for date */
  char   entry0[CHAR_BUF_LENGTH];
  int    count=0;
  char   name[CHAR_BUF_LENGTH];
  char   class[CHAR_BUF_LENGTH];

  if (!f || mcdisable_output_files) return;

  /* write NeXus NXroot attributes */
  /* automatically added: file_name, HDF5_Version, file_time, NeXus_version */
  nxprintattr(f, "creator",   "%s generated with " MCCODE_STRING, instrument_name);

  /* count the number of existing NXentry and create the next one */
  NXgetgroupinfo(f, &count, name, class);
  sprintf(entry0, "entry%i", count+1);

  /* create the main NXentry (mandatory in NeXus) */
  if (NXmakegroup(f, entry0, "NXentry") == NX_OK)
  if (NXopengroup(f, entry0, "NXentry") == NX_OK) {
    nxprintf(nxhandle, "program_name", MCCODE_STRING);
    nxprintf(f, "start_time", ctime(&t));
    nxprintf(f, "title", "%s%s%s simulation generated by instrument %s",
      dirname && strlen(dirname) ? dirname : ".", MC_PATHSEP_S, siminfo_name,
      instrument_name);
    nxprintattr(f, "program_name", MCCODE_STRING);
    nxprintattr(f, "instrument",   instrument_name);
    nxprintattr(f, "simulation",   "%s%s%s",
        dirname && strlen(dirname) ? dirname : ".", MC_PATHSEP_S, siminfo_name);

    /* write NeXus instrument group */
    if (NXmakegroup(f, "instrument", "NXinstrument") == NX_OK)
    if (NXopengroup(f, "instrument", "NXinstrument") == NX_OK) {
      int   i;
      char *string=NULL;

      /* write NeXus parameters(types) data =================================== */
      string = (char*)malloc(CHAR_BUF_LENGTH);
      if (string) {
        strcpy(string, "");
        for(i = 0; i < numipar; i++)
        {
          char ThisParam[CHAR_BUF_LENGTH];
          snprintf(ThisParam, CHAR_BUF_LENGTH, " %s(%s)", mcinputtable[i].name,
                  (*mcinputtypes[mcinputtable[i].type].parminfo)
                      (mcinputtable[i].name));
          if (strlen(string) + strlen(ThisParam) < CHAR_BUF_LENGTH)
            strcat(string, ThisParam);
        }
        nxprintattr(f, "Parameters",    string);
        free(string);
      }

      nxprintattr(f, "name",          instrument_name);
      nxprintf   (f, "name",          instrument_name);
      nxprintattr(f, "Source",        instrument_source);

      nxprintattr(f, "Trace_enabled", traceenabled ? "yes" : "no");
      nxprintattr(f, "Default_main",  defaultmain ?  "yes" : "no");
#ifdef MC_EMBEDDED_RUNTIME
      nxprintattr(f, "Embedded_runtime", "yes");
#else
      nxprintattr(f, "Embedded_runtime", "no");
#endif

      /* add instrument source code when available */
      buffer = mcinfo_readfile(instrument_source);
      if (buffer && strlen(buffer)) {
        long length=strlen(buffer);
        nxprintf (f, "description", buffer);
        NXopendata(f,"description");
        nxprintattr(f, "file_name", instrument_source);
        nxprintattr(f, "file_size", "%li", length);
        nxprintattr(f, "MCCODE_STRING", MCCODE_STRING);
        NXclosedata(f);
        nxprintf (f,"instrument_source", "%s " MCCODE_NAME " " MCCODE_PARTICLE " Monte Carlo simulation", instrument_name);
        free(buffer);
      } else
        nxprintf (f, "description", "File %s not found (instrument description %s is missing)",
          instrument_source, instrument_name);

      if (mcnexus_embed_idf) {
        /* add Mantid/IDF.xml when available */
        char *IDFfile=NULL;
        IDFfile = (char*)malloc(CHAR_BUF_LENGTH);
        sprintf(IDFfile,"%s%s",instrument_source,".xml");
        buffer = mcinfo_readfile(IDFfile);
        if (buffer && strlen(buffer)) {
          NXmakegroup (nxhandle, "instrument_xml", "NXnote");
          NXopengroup (nxhandle, "instrument_xml", "NXnote");
          nxprintf(f, "data", buffer);
          nxprintf(f, "description", "IDF.xml file found with instrument %s", instrument_source);
          nxprintf(f, "type", "text/xml");
          NXclosegroup(f); /* instrument_xml */
          free(buffer);
        }
        free(IDFfile);
      }

      /* Add "components" entry */
      if (NXmakegroup(f, "components", "NXdata") == NX_OK) {
        NXopengroup(f, "components", "NXdata");
        nxprintattr(f, "description", "Component list for instrument %s",  instrument_name);
	NXclosegroup(f); /* components */
      } else {
	printf("Failed to create NeXus component hierarchy\n");
      }
      NXclosegroup(f); /* instrument */
    } /* NXinstrument */

    /* write NeXus simulation group */
    if (NXmakegroup(f, "simulation", "NXnote") == NX_OK)
    if (NXopengroup(f, "simulation", "NXnote") == NX_OK) {

      nxprintattr(f, "name",   "%s%s%s",
        dirname && strlen(dirname) ? dirname : ".", MC_PATHSEP_S, siminfo_name);

      nxprintf   (f, "name",      "%s",     siminfo_name);
      nxprintattr(f, "Format",    mcformat && strlen(mcformat) ? mcformat : MCCODE_NAME);
      nxprintattr(f, "URL",       "http://www.mccode.org");
      nxprintattr(f, "program",   MCCODE_STRING);
      nxprintattr(f, "Instrument",instrument_source);
      nxprintattr(f, "Trace",     mcdotrace ?     "yes" : "no");
      nxprintattr(f, "Gravitation",mcgravitation ? "yes" : "no");
      nxprintattr(f, "Seed",      "%li", mcseed);
      nxprintattr(f, "Directory", dirname);
    #ifdef USE_MPI
      if (mpi_node_count > 1)
        nxprintf(f, "Nodes", "%i",        mpi_node_count);
    #endif

      /* output parameter string ================================================ */
      if (NXmakegroup(f, "Param", "NXparameters") == NX_OK) {
	NXopengroup(f,"Param", "NXparameters");
        int i;
        char string[CHAR_BUF_LENGTH];
        for(i = 0; i < numipar; i++) {
          if (mcget_run_num() || (mcinputtable[i].val && strlen(mcinputtable[i].val))) {
            if (mcinputtable[i].par == NULL)
              strncpy(string, (mcinputtable[i].val ? mcinputtable[i].val : ""), CHAR_BUF_LENGTH);
            else
              (*mcinputtypes[mcinputtable[i].type].printer)(string, mcinputtable[i].par);

            nxprintf(f,  mcinputtable[i].name, "%s", string);
            nxprintattr(f, mcinputtable[i].name, string);
          }
        }
        NXclosegroup(f); /* Param */
      } /* NXparameters */
      NXclosegroup(f); /* simulation */
    } /* NXsimulation */

    /* create a group to hold all links for all monitors */
    NXmakegroup(f, "data", "NXdetector");

    /* leave the NXentry opened (closed at exit) */
  } /* NXentry */
} /* mcinfo_out_nexus */

/*******************************************************************************
* mccomp_placement_nexus:
*   Output absolute (3x1) position and (3x3) rotation of component instance into
*   the attribute
*     entry<N>/instrument/compname
*   requires: NXentry to be opened
*******************************************************************************/
static void mccomp_placement_nexus(NXhandle nxhandle, char* component, Coords position, Rotation rotation)
{
  /* open NeXus instrument group */

  #ifdef USE_NEXUS
  if(nxhandle) {
    if (NXopengroup(nxhandle, "instrument", "NXinstrument") == NX_OK) {
      if (NXopengroup(nxhandle, "components", "NXdata") == NX_OK) {
	if (NXmakegroup(nxhandle, component, "NXdata") == NX_OK) {
	  if (NXopengroup(nxhandle, component, "NXdata") == NX_OK) {
	    int64_t pdims[3]; pdims[0]=3; pdims[1]=0; pdims[2]=0;
	    if (NXcompmakedata64(nxhandle, "Position", NX_FLOAT64, 1, pdims, NX_COMPRESSION, pdims) == NX_OK) {
	      if (NXopendata(nxhandle, "Position") == NX_OK) {
		double pos[3]; coords_get(position, &pos[0], &pos[1], &pos[2]);
		if (NXputdata (nxhandle, pos) == NX_OK) {
		  NXclosedata(nxhandle);
		} else {
		  fprintf(stderr, "COULD NOT PUT Position field for component %s\n",component);
		}
	      } else {
		fprintf(stderr, "Warning: could not open Position field for component %s\n",component);
	      }
	    }
	    int64_t rdims[3]; rdims[0]=3; rdims[1]=3; rdims[2]=0;
	    if (NXcompmakedata64(nxhandle, "Rotation", NX_FLOAT64, 2, rdims, NX_COMPRESSION, rdims) == NX_OK) {
	      if (NXopendata(nxhandle, "Rotation") == NX_OK) {
		if (NXputdata (nxhandle, rotation) == NX_OK) {
		  NXclosedata(nxhandle);
		} else {
		  fprintf(stderr, "COULD NOT PUT Rotation field for component %s\n",component);
		}
	      } else {
		fprintf(stderr, "Warning: could not open Rotation field for component %s\n",component);
	      }
	    }
	    NXclosegroup(nxhandle); // component
	  } else {
	    printf("FAILED to open comp data group %s\n",component);
	  }
	} else {
	  printf("FAILED to create comp data group %s\n",component);
	}
	NXclosegroup(nxhandle); // components
      } else {
	printf("Failed to open NeXus component hierarchy\n");
      }
      NXclosegroup(nxhandle); // instrument
    } else {
      printf("Failed to open NeXus instrument hierarchy\n");
    }
  } else {
    fprintf(stderr,"NO NEXUS FILE\n");
  }
  #endif
} /* mccomp_placement_nexus */

/*******************************************************************************
* mcdatainfo_out_nexus: output detector header
*   mcdatainfo_out_nexus(detector) create group and write info to NeXus data file
*   open data:NXdetector then filename:NXdata and write headers/attributes
*   requires: NXentry to be opened
*******************************************************************************/
static void
mcdatainfo_out_nexus(NXhandle f, MCDETECTOR detector)
{
  char data_name[CHAR_BUF_LENGTH];
  if (!f || !detector.m || mcdisable_output_files) return;

  strcpy_valid(data_name,
    strlen(detector.filename) ?
      detector.filename : detector.component);

  /* the NXdetector group has been created in mcinfo_out_nexus (siminfo_init) */
  if (NXopengroup(f, "instrument", "NXinstrument") == NX_OK) {
    if (NXopengroup(f, "components", "NXdata") == NX_OK) {
      NXMDisableErrorReporting(); /* unactivate NeXus error messages, as creation may fail */
      NXmakegroup(f, detector.component, "NXdata");
      if (NXopengroup(f, detector.component, "NXdata") == NX_OK) {
	NXmakegroup(f, "output", "NXdetector");
	if (NXopengroup(f, "output", "NXdetector") == NX_OK) {
	  if (NXmakegroup(f, data_name, "NXdata") == NX_OK) {
	    if (NXopengroup(f, data_name, "NXdata") == NX_OK) {
	      /* output metadata (as attributes) ======================================== */
	      nxprintattr(f, "Date",       detector.date);
	      nxprintattr(f, "type",       detector.type);
	      nxprintattr(f, "Source",     detector.instrument);
	      nxprintattr(f, "component",  detector.component);
	      nxprintattr(f, "position",   detector.position);

	      nxprintattr(f, "title",      detector.title);
	      nxprintattr(f, !mcget_run_num() || mcget_run_num() >= mcget_ncount() ?
			  "Ncount" :
			  "ratio",  detector.ncount);

	      if (strlen(detector.filename)) {
		nxprintattr(f, "filename", detector.filename);
	      }

	      nxprintattr(f, "statistics", detector.statistics);
	      nxprintattr(f, "signal",     detector.signal);
	      nxprintattr(f, "values",     detector.values);

	      if (detector.rank >= 1)
		{
		  nxprintattr(f, "xvar",     detector.xvar);
		  nxprintattr(f, "yvar",     detector.yvar);
		  nxprintattr(f, "xlabel",   detector.xlabel);
		  nxprintattr(f, "ylabel",   detector.ylabel);
		  if (detector.rank > 1) {
		    nxprintattr(f, "zvar",   detector.zvar);
		    nxprintattr(f, "zlabel", detector.zlabel);
		  }
		}

	      nxprintattr(f, abs(detector.rank)==1 ?
			  "xlimits" :
			  "xylimits", detector.limits);
	      nxprintattr(f, "variables",
			  strcasestr(detector.format, "list") ? detector.ylabel : detector.variables);

	      NXclosegroup(f); // data_name
	    }
	  }
	}
	NXclosegroup(f); // output
	NXclosegroup(f); // detector.component
      }
      NXclosegroup(f); // components
    }
    NXMEnableErrorReporting();  /* re-enable NeXus error messages */
    NXclosegroup(f); // instrument
  } /* NXdetector (instrument) */ 
} /* mcdatainfo_out_nexus */

/*******************************************************************************
* mcdetector_out_axis_nexus: write detector axis into current NXdata
*   requires: NXdata to be opened
*******************************************************************************/
int mcdetector_out_axis_nexus(NXhandle f, char *label, char *var, int rank, long length, double min, double max)
{
  if (!f || length <= 1 || mcdisable_output_files || max == min) return(NX_OK);
  else {
    double *axis;
    axis=malloc(sizeof(double)*length);
    char *valid;
    valid=malloc(sizeof(char)*CHAR_BUF_LENGTH);
    int dim=(int)length;
    int i;
    int nprimary=1;
    /* create an axis from [min:max] */
    for(i = 0; i < length; i++)
      axis[i] = min+(max-min)*(i+0.5)/length;
    /* create the data set */
    strcpy_valid(valid, label);
    NXcompmakedata(f, valid, NX_FLOAT64, 1, &dim, NX_COMPRESSION, &dim);
    /* open it */
    if (NXopendata(f, valid) != NX_OK) {
      fprintf(stderr, "Warning: could not open axis rank %i '%s' (NeXus)\n",
        rank, valid);
      free(axis);
      free(valid);
      return(NX_ERROR);
    }
    /* put the axis and its attributes */
    NXputdata  (f, axis);
    nxprintattr(f, "long_name",  label);
    nxprintattr(f, "short_name", var);
    NXputattr  (f, "axis",       &rank,     1, NX_INT32);
    nxprintattr(f, "units",      var);
    NXputattr  (f, "primary",    &nprimary, 1, NX_INT32);
    NXclosedata(f);
    free(axis);
    free(valid);
    return(NX_OK);
  }
} /* mcdetector_out_axis_nexus */

/*******************************************************************************
* mcdetector_out_array_nexus: write detector array into current NXdata (1D,2D)
*   requires: NXdata to be opened
*******************************************************************************/
int mcdetector_out_array_nexus(NXhandle f, char *part, double *data, MCDETECTOR detector)
{

  int64_t dims[3]={detector.m,detector.n,detector.p};  /* number of elements to write */
  int64_t fulldims[3]={detector.m,detector.n,detector.p};
  int signal=1;
  int exists=0;
  int64_t current_dims[3]={0,0,0};
  int ret=NX_OK;

  if (!f || !data || !detector.m || mcdisable_output_files) return(NX_OK);

  /* when this is a list, we set 1st dimension to NX_UNLIMITED for creation */
  if (strcasestr(detector.format, "list")) fulldims[0] = NX_UNLIMITED;

  /* create the data set in NXdata group */
  NXMDisableErrorReporting(); /* unactivate NeXus error messages, as creation may fail */
  ret = NXcompmakedata64(f, part, NX_FLOAT64, detector.rank, fulldims, NX_COMPRESSION, dims);
  if (ret != NX_OK) {
    /* failed: data set already exists */
    int datatype=0;
    int rank=0;
    exists=1;
    /* inquire current size of data set (nb of events stored) */
    NXopendata(f, part);
    NXgetinfo64(f, &rank, current_dims, &datatype);
    NXclosedata(f);
  }
  NXMEnableErrorReporting();  /* re-enable NeXus error messages */

  /* open the data set */
  if (NXopendata(f, part) == NX_ERROR) {
    fprintf(stderr, "Warning: could not open DataSet %s '%s' (NeXus)\n",
      part, detector.title);
    return(NX_ERROR);
  }
  if (strcasestr(detector.format, "list")) {
    current_dims[1] = current_dims[2] = 0; /* set starting location for writing slab */
    NXputslab64(f, data, current_dims, dims);
    if (!exists)
      printf("Events:   \"%s\"\n",
        strlen(detector.filename) ? detector.filename : detector.component);
    else
      printf("Append:   \"%s\"\n",
	     strlen(detector.filename) ? detector.filename : detector.component);
  } else {
    NXputdata (f, data);
  }

  if (strstr(part,"data") || strstr(part, "events")) {
    NXputattr(f, "signal", &signal, 1, NX_INT32);
    nxprintattr(f, "short_name", strlen(detector.filename) ?
      detector.filename : detector.component);
  }
  nxprintattr(f, "long_name", "%s '%s'", part, detector.title);
  NXclosedata(f);

  return(NX_OK);
} /* mcdetector_out_array_nexus */

/*******************************************************************************
* mcdetector_out_data_nexus: write detector axes+data into current NXdata
*   The data:NXdetector is opened, then filename:NXdata
*   requires: NXentry to be opened
*******************************************************************************/
int mcdetector_out_data_nexus(NXhandle f, MCDETECTOR detector)
{
  char data_name[CHAR_BUF_LENGTH];

  if (!f || !detector.m || mcdisable_output_files) return(NX_OK);

  strcpy_valid(data_name,
    strlen(detector.filename) ?
      detector.filename : detector.component);
  NXlink pLink;
  /* the NXdetector group has been created in mcinfo_out_nexus (siminfo_init) */
  if (NXopengroup(f, "instrument", "NXinstrument") == NX_OK) {
    if (NXopengroup(f, "components", "NXdata") == NX_OK) {
      if (NXopengroup(f, detector.component, "NXdata") == NX_OK) {
	if (NXopengroup(f, "output", "NXdetector") == NX_OK) {

	  /* the NXdata group has been created in mcdatainfo_out_nexus */
	  if (NXopengroup(f, data_name, "NXdata") == NX_OK) {
	    
	    MPI_MASTER(
		       nxprintattr(f, "options",
				   strlen(detector.options) ? detector.options : "None");
		       );
	    /* write axes, for histogram data sets, not for lists */
	    if (!strcasestr(detector.format, "list")) {
	      mcdetector_out_axis_nexus(f, detector.xlabel, detector.xvar,
					1, detector.m, detector.xmin, detector.xmax);
	      mcdetector_out_axis_nexus(f, detector.ylabel, detector.yvar,
					2, detector.n, detector.ymin, detector.ymax);
	      mcdetector_out_axis_nexus(f, detector.zlabel, detector.zvar,
					3, detector.p, detector.zmin, detector.zmax); 
	    } else {
	      	    MPI_MASTER(
			       nxprintattr(f, "dataset columns",
					   strlen(detector.ylabel) ? detector.ylabel : "None");
		    );
	    }

	    /* write the actual data (appended if already exists) */
	    if (!strcasestr(detector.format, "list") && !strcasestr(detector.format, "pixels")) {
	      mcdetector_out_array_nexus(f, "data", detector.p1, detector);
	      mcdetector_out_array_nexus(f, "errors", detector.p2, detector);
	      mcdetector_out_array_nexus(f, "ncount", detector.p0, detector);
	    } else if (strcasestr(detector.format, "pixels")) {
	      mcdetector_out_array_nexus(  f, "pixels", detector.p1, detector);
	    } else {
	      mcdetector_out_array_nexus(  f, "events", detector.p1, detector);
	    }
	    NXclosegroup(f);
	    NXopengroup(f, data_name, "NXdata");
	    NXgetgroupID(nxhandle, &pLink);
	    NXclosegroup(f);
	  } /* NXdata data_name*/
	  NXclosegroup(f);
	} /* NXdetector output */
	NXclosegroup(f);
      } /* NXdata detector.component */
      NXclosegroup(f);
    } /* NXdata components */
    NXclosegroup(f);
  } /* NXdata instrument */
  
  if (!strcasestr(detector.format, "pixels")) {
    if (NXopengroup(f, "data", "NXdetector") == NX_OK) {
      NXmakelink(nxhandle, &pLink);
      NXclosegroup(f);
    }
  }
  return(NX_OK);
} /* mcdetector_out_array_nexus */

#ifdef USE_MPI
/*******************************************************************************
* mcdetector_out_list_slaves: slaves send their list data to master which writes
*   requires: NXentry to be opened
* WARNING: this method has a flaw: it requires all nodes to flush the lists
*   the same number of times. In case one node is just below the buffer size
*   when finishing (e.g. monitor_nd), it may not trigger save but others may.
*   Then the number of recv/send is not constant along nodes, and simulation stalls.
*******************************************************************************/
MCDETECTOR mcdetector_out_list_slaves(MCDETECTOR detector)
{
  int     node_i=0;
  MPI_MASTER(
	     printf("\n** MPI master gathering slave node list data ** \n");
  );

  if (mpi_node_rank != mpi_node_root) {
    /* MPI slave: slaves send their data to master: 2 MPI_Send calls */
    /* m, n, p must be sent first, since all slaves do not have the same number of events */
    int mnp[3]={detector.m,detector.n,detector.p};

    if (mc_MPI_Send(mnp, 3, MPI_INT, mpi_node_root)!= MPI_SUCCESS)
      fprintf(stderr, "Warning: proc %i to master: MPI_Send mnp list error (mcdetector_out_list_slaves)\n", mpi_node_rank);
    if (!detector.p1
     || mc_MPI_Send(detector.p1, mnp[0]*mnp[1]*mnp[2], MPI_DOUBLE, mpi_node_root) != MPI_SUCCESS)
      fprintf(stderr, "Warning: proc %i to master: MPI_Send p1 list error: mnp=%i (mcdetector_out_list_slaves)\n", mpi_node_rank, abs(mnp[0]*mnp[1]*mnp[2]));
    /* slaves are done: sent mnp and p1 */
  } /* end slaves */

  /* MPI master: receive data from slaves sequentially: 2 MPI_Recv calls */

  if (mpi_node_rank == mpi_node_root) {
    for(node_i=0; node_i<mpi_node_count; node_i++) {
      double *this_p1=NULL;                               /* buffer to hold the list from slaves */
      int     mnp[3]={0,0,0};  /* size of this buffer */
      if (node_i != mpi_node_root) { /* get data from slaves */
	if (mc_MPI_Recv(mnp, 3, MPI_INT, node_i) != MPI_SUCCESS)
	  fprintf(stderr, "Warning: master from proc %i: "
		  "MPI_Recv mnp list error (mcdetector_write_data)\n", node_i);
	if (mnp[0]*mnp[1]*mnp[2]) {
	  this_p1 = (double *)calloc(mnp[0]*mnp[1]*mnp[2], sizeof(double));
	  if (!this_p1 || mc_MPI_Recv(this_p1, abs(mnp[0]*mnp[1]*mnp[2]), MPI_DOUBLE, node_i)!= MPI_SUCCESS)
	    fprintf(stderr, "Warning: master from proc %i: "
		    "MPI_Recv p1 list error: mnp=%i (mcdetector_write_data)\n", node_i, mnp[0]*mnp[1]*mnp[2]);
	  else {
	    printf(". MPI master writing data for slave node %i\n",node_i);
	    detector.p1 = this_p1;
	    detector.m  = mnp[0]; detector.n  = mnp[1]; detector.p  = mnp[2];

	    mcdetector_out_data_nexus(nxhandle, detector);
	  }
	}
      } /* if not master */
      free(this_p1);
    } /* for */
  MPI_MASTER(
	     printf("\n** Done ** \n");
  );
  }
  // Common return statement for slaves / master alike
  return(detector);
}
#endif

MCDETECTOR mcdetector_out_0D_nexus(MCDETECTOR detector)
{
  /* Write data set information to NeXus file. */
  MPI_MASTER(
    mcdatainfo_out_nexus(nxhandle, detector);
  );

  return(detector);
} /* mcdetector_out_0D_ascii */

MCDETECTOR mcdetector_out_1D_nexus(MCDETECTOR detector)
{
  MPI_MASTER(
  mcdatainfo_out_nexus(nxhandle, detector);
  mcdetector_out_data_nexus(nxhandle, detector);
  );
  return(detector);
} /* mcdetector_out_1D_ascii */

MCDETECTOR mcdetector_out_2D_nexus(MCDETECTOR detector)
{
  MPI_MASTER(
  mcdatainfo_out_nexus(nxhandle, detector);
  mcdetector_out_data_nexus(nxhandle, detector);
  );

#ifdef USE_MPI // and USE_NEXUS
  /* NeXus: slave nodes have master write their lists */
  if (strcasestr(detector.format, "list") && mpi_node_count > 1) {
    mcdetector_out_list_slaves(detector);
  }
#endif /* USE_MPI */

  return(detector);
} /* mcdetector_out_2D_nexus */

MCDETECTOR mcdetector_out_3D_nexus(MCDETECTOR detector)
{
  printf("Received detector from %s\n",detector.component);
  MPI_MASTER(
  mcdatainfo_out_nexus(nxhandle, detector);
  mcdetector_out_data_nexus(nxhandle, detector);
  );
  return(detector);
} /* mcdetector_out_3D_nexus */


#endif /* USE_NEXUS*/








/* ========================================================================== */

/*                            Main input functions                            */
/*            DETECTOR_OUT_xD function calls -> ascii or NeXus                */

/* ========================================================================== */

/*******************************************************************************
* siminfo_init:   open SIM and write header
*******************************************************************************/
FILE *siminfo_init(FILE *f)
{
  int exists=0;

  /* check format */
  if (!mcformat || !strlen(mcformat)
   || !strcasecmp(mcformat, "MCSTAS") || !strcasecmp(mcformat, "MCXTRACE")
   || !strcasecmp(mcformat, "PGPLOT") || !strcasecmp(mcformat, "GNUPLOT") || !strcasecmp(mcformat, "MCCODE")
   || !strcasecmp(mcformat, "MATLAB")) {
    mcformat="McCode";
#ifdef USE_NEXUS
  } else if (strcasestr(mcformat, "NeXus")) {
    /* Do nothing */
#endif
  } else {
    fprintf(stderr,
	    "Warning: You have requested the output format %s which is unsupported by this binary. Resetting to standard %s format.\n",mcformat ,"McCode");
    mcformat="McCode";
  }

  /* open the SIM file if not defined yet */
  if (siminfo_file || mcdisable_output_files)
    return (siminfo_file);

#ifdef USE_NEXUS
  /* only master writes NeXus header: calls NXopen(nxhandle) */
  if (mcformat && strcasestr(mcformat, "NeXus")) {
	  MPI_MASTER(
	  siminfo_file = mcnew_file(siminfo_name, "h5", &exists);
    if(!siminfo_file)
      fprintf(stderr,
	      "Warning: could not open simulation description file '%s'\n",
	      siminfo_name);
	  else
	    mcinfo_out_nexus(nxhandle);
	  );
    return(siminfo_file); /* points to nxhandle */
  }
#endif

  /* write main description file (only MASTER) */
  MPI_MASTER(

  siminfo_file = mcnew_file(siminfo_name, "sim", &exists);
  if(!siminfo_file)
    fprintf(stderr,
	    "Warning: could not open simulation description file '%s'\n",
	    siminfo_name);
  else
  {
    /* write SIM header */
    time_t t=time(NULL);
    siminfo_out("%s simulation description file for %s.\n",
      MCCODE_NAME, instrument_name);
    siminfo_out("Date:    %s", ctime(&t)); /* includes \n */
    siminfo_out("Program: %s\n\n", MCCODE_STRING);

    siminfo_out("begin instrument: %s\n", instrument_name);
    mcinfo_out(   "  ", siminfo_file);
    siminfo_out("end instrument\n");

    siminfo_out("\nbegin simulation: %s\n", dirname);
    mcruninfo_out("  ", siminfo_file);
    siminfo_out("end simulation\n");

  }
  return (siminfo_file);

  ); /* MPI_MASTER */

} /* siminfo_init */

/*******************************************************************************
*   siminfo_close:  close SIM
*******************************************************************************/
void siminfo_close()
{
#ifdef USE_MPI
  if(mpi_node_rank == mpi_node_root) {
#endif
  if(siminfo_file && !mcdisable_output_files) {
#ifdef USE_NEXUS
    if (mcformat && strcasestr(mcformat, "NeXus")) {
      time_t t=time(NULL);
      nxprintf(nxhandle, "end_time", ctime(&t));
      nxprintf(nxhandle, "duration", "%li", (long)t-mcstartdate);
      NXclosegroup(nxhandle); /* NXentry */
      NXclose(&nxhandle);
    } else {
#endif
      fclose(siminfo_file);
#ifdef USE_NEXUS
    }
#endif
#ifdef USE_MPI
  }
#endif
    siminfo_file = NULL;
  }
} /* siminfo_close */

/*******************************************************************************
* mcdetector_out_0D: wrapper for 0D (single value).
*   Output single detector/monitor data (p0, p1, p2).
*   Title is t, component name is c.
*******************************************************************************/
MCDETECTOR mcdetector_out_0D(char *t, double p0, double p1, double p2,
			     char *c, Coords posa, Rotation rota)
{
  /* import and perform basic detector analysis (and handle MPI reduce) */
  MCDETECTOR detector = detector_import(mcformat,
    c, (t ? t : MCCODE_STRING " data"),
    1, 1, 1,
    "I", "", "",
    "I", "", "",
    0, 0, 0, 0, 0, 0, c,
    &p0, &p1, &p2, posa, rota); /* write Detector: line */

#ifdef USE_NEXUS
  if (strcasestr(detector.format, "NeXus"))
    return(mcdetector_out_0D_nexus(detector));
  else
#endif
    return(mcdetector_out_0D_ascii(detector));

} /* mcdetector_out_0D */



/*******************************************************************************
* mcdetector_out_1D: wrapper for 1D.
*   Output 1d detector data (p0, p1, p2) for n bins linearly
*   distributed across the range x1..x2 (x1 is lower limit of first
*   bin, x2 is upper limit of last bin). Title is t, axis labels are xl
*   and yl. File name is f, component name is c.
*
*   t:    title
*   xl:   x-label
*   yl:   y-label
*   xvar: measured variable length
*   x1:   x axus min
*   x2:   x axis max
*   n:    1d data vector lenght
*   p0:   pntr to start of data block#0
*   p1:   pntr to start of data block#1
*   p2:   pntr to start of data block#2
*   f:    filename
*
*   Not included in the macro, and here forwarded to detector_import:
*   c:    ?
*   posa: ?
*******************************************************************************/
MCDETECTOR mcdetector_out_1D(char *t, char *xl, char *yl,
        char *xvar, double x1, double x2,
        long n,
        double *p0, double *p1, double *p2, char *f,
	char *c, Coords posa, Rotation rota)
{
  /* import and perform basic detector analysis (and handle MPI_Reduce) */
  // detector_import calls mcdetector_statistics, which will return different
  // MCDETECTOR versions for 1-D data based on the value of mcformat.
  //
  MCDETECTOR detector = detector_import(mcformat,
    c, (t ? t : MCCODE_STRING " 1D data"),
    n, 1, 1,
    xl, yl, (n > 1 ? "Signal per bin" : " Signal"),
    xvar, "(I,I_err)", "I",
    x1, x2, 0, 0, 0, 0, f,
    p0, p1, p2, posa, rota); /* write Detector: line */
  if (!detector.p1 || !detector.m) return(detector);

#ifdef USE_NEXUS
  if (strcasestr(detector.format, "NeXus"))
    detector = mcdetector_out_1D_nexus(detector);
  else
#endif
    detector = mcdetector_out_1D_ascii(detector);
  if (detector.p1 != p1 && detector.p1) {
    // mcdetector_statistics allocated memory but it hasn't been freed.
    free(detector.p1);
    // plus undo the other damage done there:
    detector.p0 = p0; // was set to NULL
    detector.p1 = p1; // was set to this_p1
    detector.p2 = p2; // was set to NULL
    detector.m = detector.n; // (e.g., labs(n))
    detector.n = 1;  // not (n x n)
    detector.istransposed = n < 0 ? 1 : 0;
  }
  return detector;

} /* mcdetector_out_1D */

/*******************************************************************************
* mcdetector_out_2D: wrapper for 2D.
*   Special case for list: master creates file first, then slaves append their
*   blocks without header-
*
*   t:    title
*   xl:   x-label
*   yl:   y-label
*   x1:   x axus min
*   x2:   x axis max
*   y1:   y axis min
*   y2:   y axis max
*   m:    dim 1 (x) size
*   n:    dim 2 (y) size
*   p0:   pntr to start of data block#0
*   p1:   pntr to start of data block#1
*   p2:   pntr to start of data block#2
*   f:    filename
*
*   Not included in the macro, and here forwarded to detector_import:
*   c:    ?
*   posa: ?
*   rota: ?
*******************************************************************************/
MCDETECTOR mcdetector_out_2D(char *t, char *xl, char *yl,
                  double x1, double x2, double y1, double y2,
                  long m, long n,
                  double *p0, double *p1, double *p2, char *f,
		  char *c, Coords posa, Rotation rota)
{
  char xvar[CHAR_BUF_LENGTH];
  char yvar[CHAR_BUF_LENGTH];

  /* create short axes labels */
  if (xl && strlen(xl)) { strncpy(xvar, xl, CHAR_BUF_LENGTH); xvar[2]='\0'; }
  else strcpy(xvar, "x");
  if (yl && strlen(yl)) { strncpy(yvar, yl, CHAR_BUF_LENGTH); yvar[2]='\0'; }
  else strcpy(yvar, "y");

  MCDETECTOR detector;

  /* import and perform basic detector analysis (and handle MPI_Reduce) */
  if (labs(m) == 1) {/* n>1 on Y, m==1 on X: 1D, no X axis*/
    detector = detector_import(mcformat,
      c, (t ? t : MCCODE_STRING " 1D data"),
      n, 1, 1,
      yl, "", "Signal per bin",
      yvar, "(I,Ierr)", "I",
      y1, y2, x1, x2, 0, 0, f,
      p0, p1, p2, posa, rota); /* write Detector: line */
  } else if (labs(n)==1) {/* m>1 on X, n==1 on Y: 1D, no Y axis*/
    detector = detector_import(mcformat,
      c, (t ? t : MCCODE_STRING " 1D data"),
      m, 1, 1,
      xl, "", "Signal per bin",
      xvar, "(I,Ierr)", "I",
      x1, x2, y1, y2, 0, 0, f,
      p0, p1, p2, posa, rota); /* write Detector: line */
  }else {
    detector = detector_import(mcformat,
      c, (t ? t : MCCODE_STRING " 2D data"),
      m, n, 1,
      xl, yl, "Signal per bin",
      xvar, yvar, "I",
      x1, x2, y1, y2, 0, 0, f,
      p0, p1, p2, posa, rota); /* write Detector: line */
  }

  if (!detector.p1 || !detector.m) return(detector);

#ifdef USE_NEXUS
  if (strcasestr(detector.format, "NeXus"))
    return(mcdetector_out_2D_nexus(detector));
  else
#endif
    return(mcdetector_out_2D_ascii(detector));

} /* mcdetector_out_2D */

/*******************************************************************************
* mcdetector_out_2D_list: List mode 2D including forwarding "options" from
* Monitor_nD
*
*   Special case for list: master creates file first, then slaves append their
*   blocks without header-
*
*   t:    title
*   xl:   x-label
*   yl:   y-label
*   x1:   x axus min
*   x2:   x axis max
*   y1:   y axis min
*   y2:   y axis max
*   m:    dim 1 (x) size
*   n:    dim 2 (y) size
*   p0:   pntr to start of data block#0
*   p1:   pntr to start of data block#1
*   p2:   pntr to start of data block#2
*   f:    filename
*
*   Not included in the macro, and here forwarded to detector_import:
*   c:    ?
*   posa: ?
*   rota: ?
*******************************************************************************/
MCDETECTOR mcdetector_out_2D_list(char *t, char *xl, char *yl,
                  double x1, double x2, double y1, double y2,
                  long m, long n,
                  double *p0, double *p1, double *p2, char *f,
		  char *c, Coords posa, Rotation rota, char* options)
{
  char xvar[CHAR_BUF_LENGTH];
  char yvar[CHAR_BUF_LENGTH];

  /* create short axes labels */
  if (xl && strlen(xl)) { strncpy(xvar, xl, CHAR_BUF_LENGTH); xvar[2]='\0'; }
  else strcpy(xvar, "x");
  if (yl && strlen(yl)) { strncpy(yvar, yl, CHAR_BUF_LENGTH); yvar[2]='\0'; }
  else strcpy(yvar, "y");

  MCDETECTOR detector;

  /* import and perform basic detector analysis (and handle MPI_Reduce) */
  if (labs(m) == 1) {/* n>1 on Y, m==1 on X: 1D, no X axis*/
    detector = detector_import(mcformat,
      c, (t ? t : MCCODE_STRING " 1D data"),
      n, 1, 1,
      yl, "", "Signal per bin",
      yvar, "(I,Ierr)", "I",
      y1, y2, x1, x2, 0, 0, f,
      p0, p1, p2, posa, rota); /* write Detector: line */
  } else if (labs(n)==1) {/* m>1 on X, n==1 on Y: 1D, no Y axis*/
    detector = detector_import(mcformat,
      c, (t ? t : MCCODE_STRING " 1D data"),
      m, 1, 1,
      xl, "", "Signal per bin",
      xvar, "(I,Ierr)", "I",
      x1, x2, y1, y2, 0, 0, f,
      p0, p1, p2, posa, rota); /* write Detector: line */
  }else {
    detector = detector_import(mcformat,
      c, (t ? t : MCCODE_STRING " 2D data"),
      m, n, 1,
      xl, yl, "Signal per bin",
      xvar, yvar, "I",
      x1, x2, y1, y2, 0, 0, f,
      p0, p1, p2, posa, rota); /* write Detector: line */
  }

  MPI_MASTER(
  if (strlen(options)) {
    strcpy(detector.options,options);
  } else {
    strcpy(detector.options,"None");
  }
  );

  if (!detector.p1 || !detector.m) return(detector);

#ifdef USE_NEXUS
  if (strcasestr(detector.format, "NeXus"))
    return(mcdetector_out_2D_nexus(detector));
  else
#endif
    return(mcdetector_out_2D_ascii(detector));

} /* mcdetector_out_2D_list */

/*******************************************************************************
* mcdetector_out_list: wrapper for list output (calls out_2D with mcformat+"list").
*   m=number of events, n=size of each event
*******************************************************************************/
MCDETECTOR mcdetector_out_list(char *t, char *xl, char *yl,
                  long m, long n,
                  double *p1, char *f,
			       char *c, Coords posa, Rotation rota, char* options)
{
  char       format_new[CHAR_BUF_LENGTH];
  char      *format_org;
  MCDETECTOR detector;

  format_org = mcformat;
  strcpy(format_new, mcformat);
  strcat(format_new, " list");
  mcformat = format_new;
  detector = mcdetector_out_2D_list(t, xl, yl,
                  1,labs(m),1,labs(n),
                  m,n,
                  NULL, p1, NULL, f,
		  c, posa,rota,options);

  mcformat = format_org;
  return(detector);
}

/*******************************************************************************
 * mcuse_dir: set data/sim storage directory and create it,
 * or exit with error if exists
 ******************************************************************************/
static void
mcuse_dir(char *dir)
{
  if (!dir || !strlen(dir)) return;
#ifdef MC_PORTABLE
  fprintf(stderr, "Error: "
          "Directory output cannot be used with portable simulation (mcuse_dir)\n");
  exit(1);
#else  /* !MC_PORTABLE */
  /* handle file://directory URL type */
  if (strncmp(dir, "file://", strlen("file://")))
    dirname = dir;
  else
    dirname = dir+strlen("file://");


#ifdef USE_MPI
  if(mpi_node_rank == mpi_node_root) {
#endif
    if(mkdir(dirname, 0777)) {
#ifndef DANSE
      fprintf(stderr, "Error: unable to create directory '%s' (mcuse_dir)\n", dir);
      fprintf(stderr, "(Maybe the directory already exists?)\n");
#endif
#ifdef USE_MPI
      MPI_Abort(MPI_COMM_WORLD, -1);
#endif
    exit(-1);
    }
#ifdef USE_MPI
    }
#endif

  /* remove trailing PATHSEP (if any) */
  while (strlen(dirname) && dirname[strlen(dirname) - 1] == MC_PATHSEP_C)
    dirname[strlen(dirname) - 1]='\0';
#endif /* !MC_PORTABLE */
} /* mcuse_dir */

/*******************************************************************************
* mcinfo: display instrument simulation info to stdout and exit
*******************************************************************************/
static void
mcinfo(void)
{
  fprintf(stdout, "begin instrument: %s\n", instrument_name);
  mcinfo_out("  ", stdout);
  fprintf(stdout, "end instrument\n");
  fprintf(stdout, "begin simulation: %s\n", dirname ? dirname : ".");
  mcruninfo_out("  ", stdout);
  fprintf(stdout, "end simulation\n");
  exit(0); /* includes MPI_Finalize in MPI mode */
} /* mcinfo */

/*******************************************************************************
* mcparameterinfo: display instrument parameter info to stdout and exit
*******************************************************************************/
static void
mcparameterinfo(void)
{
  mcparameterinfo_out("  ", stdout);
  exit(0); /* includes MPI_Finalize in MPI mode */
} /* mcparameterinfo */



#endif /* ndef MCCODE_R_IO_C */

/* end of the I/O section =================================================== */







/*******************************************************************************
* mcset_ncount: set total number of rays to generate
*******************************************************************************/
void mcset_ncount(unsigned long long int count)
{
  mcncount = count;
}

/* mcget_ncount: get total number of rays to generate */
unsigned long long int mcget_ncount(void)
{
  return mcncount;
}

/* mcget_run_num: get curent number of rays */
/* Within the TRACE scope we are now using _particle->uid directly */
unsigned long long int mcget_run_num() // shuld be (_class_particle* _particle) somehow
{
  /* This function only remains for the few cases outside TRACE where we need to know
     the number of simulated particles */
  return mcrun_num;
}

/* mcsetn_arg: get ncount from a string argument */
static void
mcsetn_arg(char *arg)
{
  mcset_ncount((long long int) strtod(arg, NULL));
}

/* mcsetseed: set the random generator seed from a string argument */
static void
mcsetseed(char *arg)
{
  mcseed = atol(arg);
  if(!mcseed) {
  //  srandom(mcseed);
  //} else {
    fprintf(stderr, "Error: seed must not be zero (mcsetseed)\n");
    exit(1);
  }
}

/* Following part is only embedded when not redundent with mccode-r.h ========= */

#ifndef MCCODE_H

/* SECTION: MCDISPLAY support. =============================================== */

/*******************************************************************************
* Just output MCDISPLAY keywords to be caught by an external plotter client.
*******************************************************************************/

void mcdis_magnify(char *what){
  // Do nothing here, better use interactive zoom from the tools
}

void mcdis_line(double x1, double y1, double z1,
                double x2, double y2, double z2){
  printf("MCDISPLAY: multiline(2,%g,%g,%g,%g,%g,%g)\n",
         x1,y1,z1,x2,y2,z2);
}

void mcdis_dashed_line(double x1, double y1, double z1,
		       double x2, double y2, double z2, int n){
  int i;
  const double dx = (x2-x1)/(2*n+1);
  const double dy = (y2-y1)/(2*n+1);
  const double dz = (z2-z1)/(2*n+1);

  for(i = 0; i < n+1; i++)
    mcdis_line(x1 + 2*i*dx,     y1 + 2*i*dy,     z1 + 2*i*dz,
	       x1 + (2*i+1)*dx, y1 + (2*i+1)*dy, z1 + (2*i+1)*dz);
}

void mcdis_multiline(int count, ...){
  va_list ap;
  double x,y,z;

  printf("MCDISPLAY: multiline(%d", count);
  va_start(ap, count);
  while(count--)
    {
    x = va_arg(ap, double);
    y = va_arg(ap, double);
    z = va_arg(ap, double);
    printf(",%g,%g,%g", x, y, z);
    }
  va_end(ap);
  printf(")\n");
}

void mcdis_rectangle(char* plane, double x, double y, double z,
		     double width, double height){
  /* draws a rectangle in the plane           */
  /* x is ALWAYS width and y is ALWAYS height */
  if (strcmp("xy", plane)==0) {
    mcdis_multiline(5,
		    x - width/2, y - height/2, z,
		    x + width/2, y - height/2, z,
		    x + width/2, y + height/2, z,
		    x - width/2, y + height/2, z,
		    x - width/2, y - height/2, z);
  } else if (strcmp("xz", plane)==0) {
    mcdis_multiline(5,
		    x - width/2, y, z - height/2,
		    x + width/2, y, z - height/2,
		    x + width/2, y, z + height/2,
		    x - width/2, y, z + height/2,
		    x - width/2, y, z - height/2);
  } else if (strcmp("yz", plane)==0) {
    mcdis_multiline(5,
		    x, y - height/2, z - width/2,
		    x, y - height/2, z + width/2,
		    x, y + height/2, z + width/2,
		    x, y + height/2, z - width/2,
		    x, y - height/2, z - width/2);
  } else {

    fprintf(stderr, "Error: Definition of plane %s unknown\n", plane);
    exit(1);
  }
}

void mcdis_circle(char *plane, double x, double y, double z, double r){
  printf("MCDISPLAY: circle('%s',%g,%g,%g,%g)\n", plane, x, y, z, r);
}

void mcdis_new_circle(double x, double y, double z, double r, double nx, double ny, double nz){
  printf("MCDISPLAY: new_circle(%g,%g,%g,%g,%g,%g,%g)\n", x, y, z, r, nx, ny, nz);
}


/* Draws a circle with center (x,y,z), radius (r), and in the plane
 * with normal (nx,ny,nz)*/
void mcdis_Circle(double x, double y, double z, double r, double nx, double ny, double nz){
    int i;
    if(nx==0 && ny && nz==0){
        for (i=0;i<24; i++){
            mcdis_line(x+r*sin(i*2*PI/24),y,z+r*cos(i*2*PI/24),
                    x+r*sin((i+1)*2*PI/24),y,z+r*cos((i+1)*2*PI/24));
        }
    }else{
        double mx,my,mz;
        /*generate perpendicular vector using (nx,ny,nz) and (0,1,0)*/
        vec_prod(mx,my,mz, 0,1,0, nx,ny,nz);
        NORM(mx,my,mz);
        /*draw circle*/
        for (i=0;i<24; i++){
            double ux,uy,uz;
            double wx,wy,wz;
            rotate(ux,uy,uz, mx,my,mz, i*2*PI/24, nx,ny,nz);
            rotate(wx,wy,wz, mx,my,mz, (i+1)*2*PI/24, nx,ny,nz);
            mcdis_line(x+ux*r,y+uy*r,z+uz*r,
                    x+wx*r,y+wy*r,z+wz*r);
        }
    }
}


/*  OLD IMPLEMENTATION
    draws a box with center at (x, y, z) and
    width (deltax), height (deltay), length (deltaz) */
void mcdis_legacy_box(double x, double y, double z,
	       double width, double height, double length){

  mcdis_rectangle("xy", x, y, z-length/2, width, height);
  mcdis_rectangle("xy", x, y, z+length/2, width, height);
  mcdis_line(x-width/2, y-height/2, z-length/2,
	     x-width/2, y-height/2, z+length/2);
  mcdis_line(x-width/2, y+height/2, z-length/2,
	     x-width/2, y+height/2, z+length/2);
  mcdis_line(x+width/2, y-height/2, z-length/2,
	     x+width/2, y-height/2, z+length/2);
  mcdis_line(x+width/2, y+height/2, z-length/2,
	     x+width/2, y+height/2, z+length/2);
}

/*  NEW 3D IMPLEMENTATION OF BOX SUPPORTS HOLLOW ALSO
    draws a box with center at (x, y, z) and
    width (deltax), height (deltay), length (deltaz) */
void mcdis_box(double x, double y, double z,
	       double width, double height, double length, double thickness, double nx, double ny, double nz){
  if (mcdotrace==2) {
    printf("MCDISPLAY: box(%g,%g,%g,%g,%g,%g,%g,%g,%g,%g)\n", x, y, z, width, height, length, thickness, nx, ny, nz);
  } else {
    mcdis_legacy_box(x, y, z, width, height, length);
    if (thickness)
      mcdis_legacy_box(x, y, z, width-thickness, height-thickness, length);
  }
}


/* OLD IMPLEMENTATION
Draws a cylinder with center at (x,y,z) with extent (r,height).
 * The cylinder axis is along the vector nx,ny,nz. */
void mcdis_legacy_cylinder( double x, double y, double z,
        double r, double height, int N, double nx, double ny, double nz){
    int i;
    /*no lines make little sense - so trigger the default*/
    if(N<=0) N=5;

    NORM(nx,ny,nz);
    double h_2=height/2.0;
    mcdis_Circle(x+nx*h_2,y+ny*h_2,z+nz*h_2,r,nx,ny,nz);
    mcdis_Circle(x-nx*h_2,y-ny*h_2,z-nz*h_2,r,nx,ny,nz);

    double mx,my,mz;
    /*generate perpendicular vector using (nx,ny,nz) and (0,1,0)*/
    if(nx==0 && ny && nz==0){
        mx=my=0;mz=1;
    }else{
        vec_prod(mx,my,mz, 0,1,0, nx,ny,nz);
        NORM(mx,my,mz);
    }
    /*draw circle*/
    for (i=0; i<24; i++){
        double ux,uy,uz;
        rotate(ux,uy,uz, mx,my,mz, i*2*PI/24, nx,ny,nz);
        mcdis_line(x+nx*h_2+ux*r, y+ny*h_2+uy*r, z+nz*h_2+uz*r,
                 x-nx*h_2+ux*r, y-ny*h_2+uy*r, z-nz*h_2+uz*r);
    }
}

/* NEW 3D IMPLEMENTATION ALSO SUPPORTING HOLLOW
Draws a cylinder with center at (x,y,z) with extent (r,height).
 * The cylinder axis is along the vector nx,ny,nz.*/
void mcdis_cylinder( double x, double y, double z,
        double r, double height, double thickness, double nx, double ny, double nz){
  if (mcdotrace==2) {
      printf("MCDISPLAY: cylinder(%g, %g, %g, %g, %g, %g, %g, %g, %g)\n",
         x, y, z, r, height, thickness, nx, ny, nz);
  } else {
    mcdis_legacy_cylinder(x, y, z,
			  r, height, 12, nx, ny, nz);
  }
}

/* Draws a cone with center at (x,y,z) with extent (r,height).
 * The cone axis is along the vector nx,ny,nz.*/
void mcdis_cone( double x, double y, double z,
        double r, double height, double nx, double ny, double nz){
  if (mcdotrace==2) {
    printf("MCDISPLAY: cone(%g, %g, %g, %g, %g, %g, %g, %g)\n",
       x, y, z, r, height, nx, ny, nz);
  } else {
    mcdis_Circle(x, y, z, r, nx, ny, nz);
    mcdis_Circle(x+0.25*height*nx, y+0.25*height*ny, z+0.25*height*nz, 0.75*r, nx, ny, nz);
    mcdis_Circle(x+0.5*height*nx, y+0.5*height*ny, z+0.5*height*nz, 0.5*r, nx, ny, nz);
    mcdis_Circle(x+0.75*height*nx, y+0.75*height*ny, z+0.75*height*nz, 0.25*r, nx, ny, nz);
    mcdis_line(x, y, z, x+height*nx, y+height*ny, z+height*nz);
  }
}

/* Draws a disc with center at (x,y,z) with extent (r).
 * The disc axis is along the vector nx,ny,nz.*/
void mcdis_disc( double x, double y, double z,
        double r, double nx, double ny, double nz){
  printf("MCDISPLAY: disc(%g, %g, %g, %g, %g, %g, %g)\n",
     x, y, z, r, nx, ny, nz);
}

/* Draws a annulus with center at (x,y,z) with extent (outer_radius) and remove inner_radius.
 * The annulus axis is along the vector nx,ny,nz.*/
void mcdis_annulus( double x, double y, double z,
        double outer_radius, double inner_radius, double nx, double ny, double nz){
  printf("MCDISPLAY: annulus(%g, %g, %g, %g, %g, %g, %g, %g)\n",
     x, y, z, outer_radius, inner_radius, nx, ny, nz);
}

/* draws a sphere with center at (x,y,z) with extent (r)*/
void mcdis_sphere(double x, double y, double z, double r){
  if (mcdotrace==2) {
    printf("MCDISPLAY: sphere(%g,%g,%g,%g)\n", x, y, z, r);
  } else {
    double nx,ny,nz;
    int i;
    int N=12;

    nx=0;ny=0;nz=1;
    mcdis_Circle(x,y,z,r,nx,ny,nz);
    for (i=1;i<N;i++){
        rotate(nx,ny,nz, nx,ny,nz, PI/N, 0,1,0);
        mcdis_Circle(x,y,z,r,nx,ny,nz);
    }
    /*lastly draw a great circle perpendicular to all N circles*/
    //mcdis_Circle(x,y,z,radius,1,0,0);

    for (i=1;i<=N;i++){
        double yy=-r+ 2*r*((double)i/(N+1));
        mcdis_Circle(x,y+yy ,z,  sqrt(r*r-yy*yy) ,0,1,0);
    }
  }
}
/* POLYHEDRON IMPLEMENTATION*/

void mcdis_polyhedron(char *vertices_faces){
  printf("MCDISPLAY: polyhedron %s\n", vertices_faces);
}

/* POLYGON IMPLEMENTATION */
void mcdis_polygon(int count, ...){
  va_list ap;
  double *x,*y,*z;

  double x0=0,y0=0,z0=0; /* Used for centre-of-mass in trace==2 */

  x=malloc(count*sizeof(double));
  y=malloc(count*sizeof(double));
  z=malloc(count*sizeof(double));

  va_start(ap, count);
  // Fallback for trace==1 is multiline, one rank higher
  if (mcdotrace==1) {
    printf("MCDISPLAY: multiline(%i,",count+1);
  }
  
  int j;
  for (j=0; j<count; j++) {
    x[j] = va_arg(ap, double);
    y[j] = va_arg(ap, double);
    z[j] = va_arg(ap, double);
    if (mcdotrace==1) {
      printf("%g,%g,%g,",x[j],y[j],z[j]);
    } else {
      // Calculation of polygon centre of mass
      x0 += x[j]; y0 += y[j]; z0 += z[j];
    }
  }
  va_end(ap);

  /* Patch data for multiline(count+1, ... use 0th point*/
  if (mcdotrace==1) {
    printf("%g,%g,%g)\n",x[0],y[0],z[0]);
  } else {
    x0 /= count; y0 /= count; z0 /= count;
    /* Build up a json string for a "polyhedron" */
    // Estimate size of the JSON string
    const int VERTEX_OVERHEAD = 30;
    const int FACE_OVERHEAD_BASE = 20;
    const int FACE_INDEX_OVERHEAD = 15;
    int estimated_size = 256; // Base size
    estimated_size += count * VERTEX_OVERHEAD;

    int faceSize;
    int vtxSize;
    if (count > 3) {
      /* Split in triangles - as many as polygon rank */
      faceSize=count;
      vtxSize=count+1;
    } else {
      faceSize=1;
      vtxSize=count;
    }
    
    for (int i = 0; i < faceSize;) {
        int num_indices = 3;
        estimated_size += FACE_OVERHEAD_BASE + num_indices * FACE_INDEX_OVERHEAD;
        i += num_indices + 1;
    }

    char *json_string = malloc(estimated_size);
    if (json_string == NULL) {
        fprintf(stderr, "Memory allocation failed.\n");
        return;
    }

    char *ptr = json_string;
    ptr += sprintf(ptr, "{ \"vertices\": [");

    if (count==3) { // Single, basic triangle
      ptr += sprintf(ptr, "[%g, %g, %g], [%g, %g, %g], [%g, %g, %g]", x[0], y[0], z[0], x[1], y[1], z[1], x[2], y[2], z[2]);
    } else {
      for (int i = 0; i < vtxSize-1; i++) {
        ptr += sprintf(ptr, "[%g, %g, %g]", x[i], y[i], z[i]);
        if (i < vtxSize - 2) {
	  ptr += sprintf(ptr, ", ");
        } else {
	  ptr += sprintf(ptr, ", [%g, %g, %g]", x0, y0, z0);
	}
      }
    }
    ptr += sprintf(ptr, "], \"faces\": [");
    if (count==3) { // Single, basic triangle, 1 face...
      ptr += sprintf(ptr, "{ \"face\": [");
      ptr += sprintf(ptr, "0, 1, 2");
      ptr += sprintf(ptr, "]}");
    } else {
      for (int i = 0; i < faceSize; i++) {
        int num = 3;
        ptr += sprintf(ptr, "{ \"face\": [");
	if (i < faceSize - 1) {
	  ptr += sprintf(ptr, "%d, %d, %d",i,i+1,count);
	} else {
	  ptr += sprintf(ptr, "%d, %d, %d",i,count,0);
	}
	ptr += sprintf(ptr, "]}");
	if (i < faceSize-1) {
	  ptr += sprintf(ptr, ", ");
	}
      }
    }
    ptr += sprintf(ptr, "]}");
    mcdis_polyhedron(json_string);

    free(json_string);
  }
  free(x);free(y);free(z);
}
/* END NEW POLYGON IMPLEMENTATION*/

/*
void mcdis_polygon(double x1, double y1, double z1,
                double x2, double y2, double z2){
  printf("MCDISPLAY: polygon(2,%g,%g,%g,%g,%g,%g)\n",
         x1,y1,z1,x2,y2,z2);
}
*/

/* SECTION: coordinates handling ============================================ */

/*******************************************************************************
* Since we use a lot of geometric calculations using Cartesian coordinates,
* we collect some useful routines here. However, it is also permissible to
* work directly on the underlying struct coords whenever that is most
* convenient (that is, the type Coords is not abstract).
*
* Coordinates are also used to store rotation angles around x/y/z axis.
*
* Since coordinates are used much like a basic type (such as double), the
* structure itself is passed and returned, rather than a pointer.
*
* At compile-time, the values of the coordinates may be unknown (for example
* a motor position). Hence coordinates are general expressions and not simple
* numbers. For this we used the type Coords_exp which has three CExp
* fields. For runtime (or calculations possible at compile time), we use
* Coords which contains three double fields.
*******************************************************************************/

/* coords_set: Assign coordinates. */
Coords coords_set(MCNUM x, MCNUM y, MCNUM z)
{
  Coords a;

  a.x = x;
  a.y = y;
  a.z = z;
  return a;
}

/* coords_get: get coordinates. Required when 'x','y','z' are #defined as ray pars */
Coords coords_get(Coords a, MCNUM *x, MCNUM *y, MCNUM *z)
{
  *x = a.x;
  *y = a.y;
  *z = a.z;
  return a;
}

/* coords_add: Add two coordinates. */
Coords coords_add(Coords a, Coords b)
{
  Coords c;

  c.x = a.x + b.x;
  c.y = a.y + b.y;
  c.z = a.z + b.z;
  if (fabs(c.z) < 1e-14) c.z=0.0;
  return c;
}

/* coords_sub: Subtract two coordinates. */
Coords coords_sub(Coords a, Coords b)
{
  Coords c;

  c.x = a.x - b.x;
  c.y = a.y - b.y;
  c.z = a.z - b.z;
  if (fabs(c.z) < 1e-14) c.z=0.0;
  return c;
}

/* coords_neg: Negate coordinates. */
Coords coords_neg(Coords a)
{
  Coords b;

  b.x = -a.x;
  b.y = -a.y;
  b.z = -a.z;
  return b;
}

/* coords_scale: Scale a vector. */
Coords coords_scale(Coords b, double scale) {
  Coords a;

  a.x = b.x*scale;
  a.y = b.y*scale;
  a.z = b.z*scale;
  return a;
}

/* coords_sp: Scalar product: a . b */
double coords_sp(Coords a, Coords b) {
  double value;

  value = a.x*b.x + a.y*b.y + a.z*b.z;
  return value;
}

/* coords_xp: Cross product: a = b x c. */
Coords coords_xp(Coords b, Coords c) {
  Coords a;

  a.x = b.y*c.z - c.y*b.z;
  a.y = b.z*c.x - c.z*b.x;
  a.z = b.x*c.y - c.x*b.y;
  return a;
}

/* coords_len: Gives length of coords set. */
double coords_len(Coords a) {
  return sqrt(a.x*a.x + a.y*a.y + a.z*a.z);
}

/* coords_mirror: Mirror a in plane (through the origin) defined by normal n*/
Coords coords_mirror(Coords a, Coords n) {
  double t = scalar_prod(n.x, n.y, n.z, n.x, n.y, n.z);
  Coords b;
  if (t!=1) {
    t = sqrt(t);
    n.x /= t;
    n.y /= t;
    n.z /= t;
  }
  t=scalar_prod(a.x, a.y, a.z, n.x, n.y, n.z);
  b.x = a.x-2*t*n.x;
  b.y = a.y-2*t*n.y;
  b.z = a.z-2*t*n.z;
  return b;
}

/* coords_print: Print out vector values. */
void coords_print(Coords a) {
  #ifndef OPENACC
  fprintf(stdout, "(%f, %f, %f)\n", a.x, a.y, a.z);
  #endif
  return;
}

mcstatic void coords_norm(Coords* c) {
	double temp = coords_sp(*c,*c);

	// Skip if we will end dividing by zero
	if (temp == 0) return;

	temp = sqrt(temp);

	c->x /= temp;
	c->y /= temp;
	c->z /= temp;
}

/* coords_test_zero: check if zero vector*/
int coords_test_zero(Coords a){
  return ( a.x==0 && a.y==0 && a.z==0 );
}

/*******************************************************************************
* The Rotation type implements a rotation transformation of a coordinate
* system in the form of a double[3][3] matrix.
*
* Contrary to the Coords type in coords.c, rotations are passed by
* reference. Functions that yield new rotations do so by writing to an
* explicit result parameter; rotations are not returned from functions. The
* reason for this is that arrays cannot by returned from functions (though
* structures can; thus an alternative would have been to wrap the
* double[3][3] array up in a struct). Such are the ways of C programming.
*
* A rotation represents the tranformation of the coordinates of a vector when
* changing between coordinate systems that are rotated with respect to each
* other. For example, suppose that coordinate system Q is rotated 45 degrees
* around the Z axis with respect to coordinate system P. Let T be the
* rotation transformation representing a 45 degree rotation around Z. Then to
* get the coordinates of a vector r in system Q, apply T to the coordinates
* of r in P. If r=(1,0,0) in P, it will be (sqrt(1/2),-sqrt(1/2),0) in
* Q. Thus we should be careful when interpreting the sign of rotation angles:
* they represent the rotation of the coordinate systems, not of the
* coordinates (which has opposite sign).
*******************************************************************************/

/*******************************************************************************
* rot_set_rotation: Get transformation for rotation first phx around x axis,
* then phy around y, then phz around z.
*******************************************************************************/
void rot_set_rotation(Rotation t, double phx, double phy, double phz)
{
  if ((phx == 0) && (phy == 0) && (phz == 0)) {
    t[0][0] = 1.0;
    t[0][1] = 0.0;
    t[0][2] = 0.0;
    t[1][0] = 0.0;
    t[1][1] = 1.0;
    t[1][2] = 0.0;
    t[2][0] = 0.0;
    t[2][1] = 0.0;
    t[2][2] = 1.0;
  } else {
    double cx = cos(phx);
    double sx = sin(phx);
    double cy = cos(phy);
    double sy = sin(phy);
    double cz = cos(phz);
    double sz = sin(phz);

    t[0][0] = cy*cz;
    t[0][1] = sx*sy*cz + cx*sz;
    t[0][2] = sx*sz - cx*sy*cz;
    t[1][0] = -cy*sz;
    t[1][1] = cx*cz - sx*sy*sz;
    t[1][2] = sx*cz + cx*sy*sz;
    t[2][0] = sy;
    t[2][1] = -sx*cy;
    t[2][2] = cx*cy;
  }
}

/*******************************************************************************
* rot_test_identity: Test if rotation is identity
*******************************************************************************/
int rot_test_identity(Rotation t)
{
  return (t[0][0] + t[1][1] + t[2][2] == 3);
}

/*******************************************************************************
* rot_mul: Matrix multiplication of transformations (this corresponds to
* combining transformations). After rot_mul(T1, T2, T3), doing T3 is
* equal to doing first T2, then T1.
* Note that T3 must not alias (use the same array as) T1 or T2.
*******************************************************************************/
void rot_mul(Rotation t1, Rotation t2, Rotation t3)
{
  if (rot_test_identity(t1)) {
    rot_copy(t3, t2);
  } else if (rot_test_identity(t2)) {
    rot_copy(t3, t1);
  } else {
    int i,j;
    for(i = 0; i < 3; i++)
      for(j = 0; j < 3; j++)
	t3[i][j] = t1[i][0]*t2[0][j] + t1[i][1]*t2[1][j] + t1[i][2]*t2[2][j];
  }
}

/*******************************************************************************
* rot_copy: Copy a rotation transformation (arrays cannot be assigned in C).
*******************************************************************************/
void rot_copy(Rotation dest, Rotation src)
{
  int i,j;
  for(i = 0; i < 3; i++)
    for(j = 0; j < 3; j++)
      dest[i][j] = src[i][j];
}

/*******************************************************************************
* rot_transpose: Matrix transposition, which is inversion for Rotation matrices
*******************************************************************************/
void rot_transpose(Rotation src, Rotation dst)
{
  dst[0][0] = src[0][0];
  dst[0][1] = src[1][0];
  dst[0][2] = src[2][0];
  dst[1][0] = src[0][1];
  dst[1][1] = src[1][1];
  dst[1][2] = src[2][1];
  dst[2][0] = src[0][2];
  dst[2][1] = src[1][2];
  dst[2][2] = src[2][2];
}

/*******************************************************************************
* rot_apply: returns t*a
*******************************************************************************/
Coords rot_apply(Rotation t, Coords a)
{
  Coords b;
  if (rot_test_identity(t)) {
    return a;
  } else {
    b.x = t[0][0]*a.x + t[0][1]*a.y + t[0][2]*a.z;
    b.y = t[1][0]*a.x + t[1][1]*a.y + t[1][2]*a.z;
    b.z = t[2][0]*a.x + t[2][1]*a.y + t[2][2]*a.z;
    return b;
  }
}

/**
 * Pretty-printing of rotation matrices.
 */
void rot_print(Rotation rot) {
	printf("[ %4.2f %4.2f %4.2f ]\n",
			rot[0][0], rot[0][1], rot[0][2]);
	printf("[ %4.2f %4.2f %4.2f ]\n",
			rot[1][0], rot[1][1], rot[1][2]);
	printf("[ %4.2f %4.2f %4.2f ]\n\n",
			rot[2][0], rot[2][1], rot[2][2]);
}

/**
 * Vector product: used by vec_prod (mccode-r.h). Use coords_xp for Coords.
 */
void vec_prod_func(double *x, double *y, double *z,
		double x1, double y1, double z1,
		double x2, double y2, double z2) {
    *x = (y1)*(z2) - (y2)*(z1);
    *y = (z1)*(x2) - (z2)*(x1);
    *z = (x1)*(y2) - (x2)*(y1);
}

/**
 * Scalar product: use coords_sp for Coords.
 */
double scalar_prod(
		double x1, double y1, double z1,
		double x2, double y2, double z2) {
	return ((x1 * x2) + (y1 * y2) + (z1 * z2));
}

mcstatic void norm_func(double *x, double *y, double *z) {
	double temp = (*x * *x) + (*y * *y) + (*z * *z);
	if (temp != 0) {
		temp = sqrt(temp);
		*x /= temp;
		*y /= temp;
		*z /= temp;
	}
}


/* SECTION: GPU algorithms ================================================== */


/*
*  Divide-and-conquer strategy for parallelizing this task: Sort absorbed
*  particles last.
*
*   particles:  the particle array, required to checking _absorbed
*   pbuffer:    same-size particle buffer array required for parallel sort
*   len:        sorting area-of-interest size (e.g. from previous calls)
*   buffer_len: total array size
*   flag_split: if set, multiply live particles into absorbed slots, up to buffer_len
*   multiplier: output arg, becomes the  SPLIT multiplier if flag_split is set
*/
#ifdef FUNNEL
long sort_absorb_last(_class_particle* particles, _class_particle* pbuffer, long len, long buffer_len, long flag_split, long* multiplier) {
  #define SAL_THREADS 1024 // num parallel sections
  if (len<SAL_THREADS) return sort_absorb_last_serial(particles, len);

  if (multiplier != NULL) *multiplier = -1; // set default out value for multiplier
  long newlen = 0;
  long los[SAL_THREADS]; // target array startidxs
  long lens[SAL_THREADS]; // target array sublens
  long l = floor(len/(SAL_THREADS-1)); // subproblem_len
  long ll = len - l*(SAL_THREADS-1); // last_subproblem_len

  // TODO: The l vs ll is too simplistic, since ll can become much larger
  // than l, resulting in idling. We should distribute lengths more evenly.

  // step 1: sort sub-arrays
  #pragma acc parallel loop present(particles[0:buffer_len], pbuffer[0:buffer_len])
  for (unsigned long tidx=0; tidx<SAL_THREADS; tidx++) {
    long lo = l*tidx;
    long loclen = l;
    if (tidx==(SAL_THREADS-1)) loclen = ll; // last sub-problem special case
    long i = lo;
    long j = lo + loclen - 1;

    // write into pbuffer at i and j
    #pragma acc loop seq
    while (i < j) {
      #pragma acc loop seq
      while (!particles[i]._absorbed && i<j) {
        pbuffer[i] = particles[i];
        i++;
      }
      #pragma acc loop seq
      while (particles[j]._absorbed && i<j) {
        pbuffer[j] = particles[j];
        j--;
      }
      if (i < j) {
        pbuffer[j] = particles[i];
        pbuffer[i] = particles[j];
        i++;
        j--;
      }
    }
    // transfer edge case
    if (i==j)
      pbuffer[i] = particles[i];

    lens[tidx] = i - lo;
    if (i==j && !particles[i]._absorbed) lens[tidx]++;
  }

  // determine lo's
  long accumlen = 0;
  #pragma acc loop seq
  for (long idx=0; idx<SAL_THREADS; idx++) {
    los[idx] = accumlen;
    accumlen = accumlen + lens[idx];
  }

  // step 2: write non-absorbed sub-arrays to psorted/output from the left
  #pragma acc parallel loop present(pbuffer[0:buffer_len])
  for (unsigned long tidx=0; tidx<SAL_THREADS; tidx++) {
    long j, k;
    #pragma acc loop seq
    for (long i=0; i<lens[tidx]; i++) {
      j = i + l*tidx;
      k = i + los[tidx];
      particles[k] = pbuffer[j];
    }
  }
  //for (int ii=0;ii<accumlen;ii++) printf("%ld ", (psorted[ii]->_absorbed));

  // return (no SPLIT)
  if (flag_split != 1)
    return accumlen;

  // SPLIT - repeat the non-absorbed block N-1 times, where len % accumlen = N + R
  int mult = buffer_len / accumlen; // TODO: possibly use a new arg, bufferlen, rather than len

  // not enough space for full-block split, return
  if (mult <= 1)
    return accumlen;

  // copy non-absorbed block
  #pragma acc parallel loop present(particles[0:buffer_len])
  for (long tidx = 0; tidx < accumlen; tidx++) { // tidx: thread index
    unsigned long randstate[7];
    _class_particle sourcebuffer;
    _class_particle targetbuffer;
    // assign reduced weight to all particles
    particles[tidx].p=particles[tidx].p/mult;
    #pragma acc loop seq
    for (long bidx = 1; bidx < mult; bidx++) { // bidx: block index
      // preserve absorbed particle (for randstate)
      sourcebuffer = particles[bidx*accumlen + tidx];
      // buffer full particle struct
      targetbuffer = particles[tidx];
      // reassign previous randstate
      targetbuffer.randstate[0] = sourcebuffer.randstate[0];
      targetbuffer.randstate[1] = sourcebuffer.randstate[1];
      targetbuffer.randstate[2] = sourcebuffer.randstate[2];
      targetbuffer.randstate[3] = sourcebuffer.randstate[3];
      targetbuffer.randstate[4] = sourcebuffer.randstate[4];
      targetbuffer.randstate[5] = sourcebuffer.randstate[5];
      targetbuffer.randstate[6] = sourcebuffer.randstate[6];
      // apply
      particles[bidx*accumlen + tidx] = targetbuffer;
    }
  }

  // set out split multiplier value
  *multiplier = mult;

  // return expanded array size
  return accumlen * mult;
}

#endif

/*
*  Fallback serial version of the one above.
*/
long sort_absorb_last_serial(_class_particle* particles, long len) {
  long i = 0;
  long j = len - 1;
  _class_particle pbuffer;

  // bubble
  while (i < j) {
    while (!particles[i]._absorbed && i<j) i++;
    while (particles[j]._absorbed && i<j) j--;
    if (i < j) {
      pbuffer = particles[j];
      particles[j] = particles[i];
      particles[i] = pbuffer;
      i++;
      j--;
    }
  }

  // return new length
  if (i==j && !particles[i]._absorbed)
    return i + 1;
  else
    return i;
}

/*******************************************************************************
* mccoordschange: applies rotation to (x y z) and (vx vy vz) and Spin (sx,sy,sz)
*******************************************************************************/
void mccoordschange(Coords a, Rotation t, _class_particle *particle)
{
  Coords b, c;

  b.x = particle->x;
  b.y = particle->y;
  b.z = particle->z;
  c = rot_apply(t, b);
  b = coords_add(c, a);
  particle->x = b.x;
  particle->y = b.y;
  particle->z = b.z;

#if MCCODE_PARTICLE_CODE == 2112
    if (particle->vz != 0.0 || particle->vx != 0.0 || particle->vy != 0.0)
      mccoordschange_polarisation(t, &(particle->vx), &(particle->vy), &(particle->vz));

    if (particle->sz != 0.0 || particle->sx != 0.0 || particle->sy != 0.0)
      mccoordschange_polarisation(t, &(particle->sx), &(particle->sy), &(particle->sz));
#elif MCCODE_PARTICLE_CODE == 22
    if (particle->kz != 0.0 || particle->kx != 0.0 || particle->ky != 0.0)
      mccoordschange_polarisation(t, &(particle->kx), &(particle->ky), &(particle->kz));

    if (particle->Ez != 0.0 || particle->Ex != 0.0 || particle->Ey != 0.0)
      mccoordschange_polarisation(t, &(particle->Ex), &(particle->Ey), &(particle->Ez));
#endif
}

/*******************************************************************************
* mccoordschange_polarisation: applies rotation to vector (sx sy sz)
*******************************************************************************/
void mccoordschange_polarisation(Rotation t, double *sx, double *sy, double *sz)
{
  Coords b, c;

  b.x = *sx;
  b.y = *sy;
  b.z = *sz;
  c = rot_apply(t, b);
  *sx = c.x;
  *sy = c.y;
  *sz = c.z;
}

/* SECTION: vector math  ==================================================== */

/* normal_vec_func: Compute normal vector to (x,y,z). */
void normal_vec(double *nx, double *ny, double *nz,
                double x, double y, double z)
{
  double ax = fabs(x);
  double ay = fabs(y);
  double az = fabs(z);
  double l;
  if(x == 0 && y == 0 && z == 0)
  {
    *nx = 0;
    *ny = 0;
    *nz = 0;
    return;
  }
  if(ax < ay)
  {
    if(ax < az)
    {                           /* Use X axis */
      l = sqrt(z*z + y*y);
      *nx = 0;
      *ny = z/l;
      *nz = -y/l;
      return;
    }
  }
  else
  {
    if(ay < az)
    {                           /* Use Y axis */
      l = sqrt(z*z + x*x);
      *nx = z/l;
      *ny = 0;
      *nz = -x/l;
      return;
    }
  }
  /* Use Z axis */
  l = sqrt(y*y + x*x);
  *nx = y/l;
  *ny = -x/l;
  *nz = 0;
} /* normal_vec */

/*******************************************************************************
 * solve_2nd_order: second order equation solve: A*t^2 + B*t + C = 0
 * solve_2nd_order(&t1, NULL, A,B,C)
 *   returns 0 if no solution was found, or set 't1' to the smallest positive
 *   solution.
 * solve_2nd_order(&t1, &t2, A,B,C)
 *   same as with &t2=NULL, but also returns the second solution.
 * EXAMPLE usage for intersection of a trajectory with a plane in gravitation
 * field (gx,gy,gz):
 * The neutron starts at point r=(x,y,z) with velocityv=(vx vy vz). The plane
 * has a normal vector n=(nx,ny,nz) and contains the point W=(wx,wy,wz).
 * The problem consists in solving the 2nd order equation:
 *      1/2.n.g.t^2 + n.v.t + n.(r-W) = 0
 * so that A = 0.5 n.g; B = n.v; C = n.(r-W);
 * Without acceleration, t=-n.(r-W)/n.v
 ******************************************************************************/
int solve_2nd_order_old(double *t1, double *t2,
                  double A,  double B,  double C)
{
  int ret=0;

  if (!t1) return 0;
  *t1 = 0;
  if (t2) *t2=0;

  if (fabs(A) < 1E-10) /* approximate to linear equation: A ~ 0 */
  {
    if (B) {  *t1 = -C/B; ret=1; if (t2) *t2=*t1; }
    /* else no intersection: A=B=0 ret=0 */
  }
  else
  {
    double D;
    D = B*B - 4*A*C;
    if (D >= 0) /* Delta > 0: two solutions */
    {
      double sD, dt1, dt2;
      sD = sqrt(D);
      dt1 = (-B + sD)/2/A;
      dt2 = (-B - sD)/2/A;
      /* we identify very small values with zero */
      if (fabs(dt1) < 1e-10) dt1=0.0;
      if (fabs(dt2) < 1e-10) dt2=0.0;

      /* now we choose the smallest positive solution */
      if      (dt1<=0.0 && dt2>0.0) ret=2; /* dt2 positive */
      else if (dt2<=0.0 && dt1>0.0) ret=1; /* dt1 positive */
      else if (dt1> 0.0 && dt2>0.0)
      {  if (dt1 < dt2) ret=1; else ret=2; } /* all positive: min(dt1,dt2) */
      /* else two solutions are negative. ret=-1 */
      if (ret==1) { *t1 = dt1;  if (t2) *t2=dt2; }
      else        { *t1 = dt2;  if (t2) *t2=dt1; }
      ret=2;  /* found 2 solutions and t1 is the positive one */
    } /* else Delta <0: no intersection. ret=0 */
  }
  return(ret);
} /* solve_2nd_order */

int solve_2nd_order(double *t0, double *t1, double A, double B, double C){
  int retval=0;
  double sign=copysign(1.0,B);
  double dt0,dt1;

  dt0=0;
  dt1=0;
  if(t1){ *t1=0;}

  /*protect against rounding errors by locally equating DBL_EPSILON with 0*/
  if (fabs(A)<DBL_EPSILON){
    A=0;
  }
  if (fabs(B)<DBL_EPSILON){
    B=0;
  }
  if (fabs(C)<DBL_EPSILON){
    C=0;
  }

  /*check if coefficient are sane*/
  if( A==0  && B==0){
    retval=0;
  }else{
    if(A==0){
      /*equation is linear*/
      dt0=-C/B;
      retval=1;
    }else if (C==0){
      /*one root is 0*/
      if(sign<0){
        dt0=0;dt1=-B/A;
      }else{
        dt0=-B/A;dt1=0;
      }
      retval=2;
    }else{
      /*a regular 2nd order eq. Also works out fine for B==0.*/
      double D;
      D=B*B-4*A*C;
      if (D>=0){
        dt0=(-B - sign*sqrt(B*B-4*A*C))/(2*A);
        dt1=C/(A*dt0);
        retval=2;
      }else{
        /*no real roots*/
        retval=0;
      }
    }
    /*sort the solutions*/
    if (retval==1){
      /*put both solutions in t0 and t1*/
      *t0=dt0;
      if(t1) *t1=dt1;
    }else{
      /*we have two solutions*/
      /*swap if both are positive and t1 smaller than t0 or t1 the only positive*/
      int swap=0;
      if(dt1>0 && ( dt1<dt0 || dt0<=0) ){
        swap=1;
      }
      if (swap){
        *t0=dt1;
        if(t1) *t1=dt0;
      }else{
        *t0=dt0;
        if(t1) *t1=dt0;
      }
    }

  }
  return retval;

} /*solve_2nd_order_improved*/


/*******************************************************************************
 * randvec_target_circle: Choose random direction towards target at (x,y,z)
 * with given radius.
 * If radius is zero, choose random direction in full 4PI, no target.
 ******************************************************************************/
void _randvec_target_circle(double *xo, double *yo, double *zo, double *solid_angle,
        double xi, double yi, double zi, double radius,
        _class_particle* _particle)
{
  double l2, phi, theta, nx, ny, nz, xt, yt, zt, xu, yu, zu;

  if(radius == 0.0)
  {
    /* No target, choose uniformly a direction in full 4PI solid angle. */
    theta = acos(1 - rand0max(2));
    phi = rand0max(2 * PI);
    if(solid_angle)
      *solid_angle = 4*PI;
    nx = 1;
    ny = 0;
    nz = 0;
    yi = sqrt(xi*xi+yi*yi+zi*zi);
    zi = 0;
    xi = 0;
  }
  else
  {
    double costheta0;
    l2 = xi*xi + yi*yi + zi*zi; /* sqr Distance to target. */
    costheta0 = sqrt(l2/(radius*radius+l2));
    if (radius < 0) costheta0 *= -1;
    if(solid_angle)
    {
      /* Compute solid angle of target as seen from origin. */
        *solid_angle = 2*PI*(1 - costheta0);
    }

    /* Now choose point uniformly on circle surface within angle theta0 */
    theta = acos (1 - rand0max(1 - costheta0)); /* radius on circle */
    phi = rand0max(2 * PI); /* rotation on circle at given radius */
    /* Now, to obtain the desired vector rotate (xi,yi,zi) angle theta around a
       perpendicular axis u=i x n and then angle phi around i. */
    if(xi == 0 && zi == 0)
    {
      nx = 1;
      ny = 0;
      nz = 0;
    }
    else
    {
      nx = -zi;
      nz = xi;
      ny = 0;
    }
  }

  /* [xyz]u = [xyz]i x n[xyz] (usually vertical) */
  vec_prod(xu,  yu,  zu, xi, yi, zi,        nx, ny, nz);
  /* [xyz]t = [xyz]i rotated theta around [xyz]u */
  rotate  (xt,  yt,  zt, xi, yi, zi, theta, xu, yu, zu);
  /* [xyz]o = [xyz]t rotated phi around n[xyz] */
  rotate (*xo, *yo, *zo, xt, yt, zt, phi, xi, yi, zi);
}
/* randvec_target_circle */

/*******************************************************************************
 * randvec_target_rect_angular: Choose random direction towards target at
 * (xi,yi,zi) with given ANGULAR dimension height x width. height=phi_x=[0,PI],
 * width=phi_y=[0,2*PI] (radians)
 * If height or width is zero, choose random direction in full 4PI, no target.
 *******************************************************************************/
void _randvec_target_rect_angular(double *xo, double *yo, double *zo, double *solid_angle,
        double xi, double yi, double zi, double width, double height, Rotation A,
        _class_particle* _particle)
{
  double theta, phi, nx, ny, nz, xt, yt, zt, xu, yu, zu;
  Coords tmp;
  Rotation Ainverse;

  rot_transpose(A, Ainverse);

  if(height == 0.0 || width == 0.0)
  {
    randvec_target_circle(xo, yo, zo, solid_angle, xi, yi, zi, 0);
    return;
  }
  else
  {
    if(solid_angle)
    {
      /* Compute solid angle of target as seen from origin. */
      *solid_angle = 2*fabs(width*sin(height/2));
    }

    /* Go to global coordinate system */

    tmp = coords_set(xi, yi, zi);
    tmp = rot_apply(Ainverse, tmp);
    coords_get(tmp, &xi, &yi, &zi);

    /* Now choose point uniformly on the unit sphere segment with angle theta/phi */
    phi   = width*randpm1()/2.0;
    theta = asin(randpm1()*sin(height/2.0));
    /* Now, to obtain the desired vector rotate (xi,yi,zi) angle theta around
       n, and then phi around u. */
    if(xi == 0 && zi == 0)
    {
      nx = 1;
      ny = 0;
      nz = 0;
    }
    else
    {
      nx = -zi;
      nz = xi;
      ny = 0;
    }
  }

  /* [xyz]u = [xyz]i x n[xyz] (usually vertical) */
  vec_prod(xu,  yu,  zu, xi, yi, zi,        nx, ny, nz);
  /* [xyz]t = [xyz]i rotated theta around [xyz]u */
  rotate  (xt,  yt,  zt, xi, yi, zi, theta, nx, ny, nz);
  /* [xyz]o = [xyz]t rotated phi around n[xyz] */
  rotate (*xo, *yo, *zo, xt, yt, zt, phi, xu,  yu,  zu);

  /* Go back to local coordinate system */
  tmp = coords_set(*xo, *yo, *zo);
  tmp = rot_apply(A, tmp);
  coords_get(tmp, &*xo, &*yo, &*zo);
}
/* randvec_target_rect_angular */

/*******************************************************************************
 * randvec_target_rect_real: Choose random direction towards target at (xi,yi,zi)
 * with given dimension height x width (in meters !).
 *
 * Local emission coordinate is taken into account and corrected for 'order' times.
 * (See remarks posted to mcstas-users by George Apostolopoulus <gapost@ipta.demokritos.gr>)
 *
 * If height or width is zero, choose random direction in full 4PI, no target.
 *
 * Traditionally, this routine had the name randvec_target_rect - this is now a
 * a define (see mcstas-r.h) pointing here. If you use the old rouine, you are NOT
 * taking the local emmission coordinate into account.
*******************************************************************************/
void _randvec_target_rect_real(double *xo, double *yo, double *zo, double *solid_angle,
        double xi, double yi, double zi,
        double width, double height, Rotation A,
        double lx, double ly, double lz, int order,
        _class_particle* _particle)
{
  double dx, dy, dist, dist_p, nx, ny, nz, mx, my, mz, n_norm, m_norm;
  double cos_theta;
  Coords tmp;
  Rotation Ainverse;

  rot_transpose(A, Ainverse);

  if(height == 0.0 || width == 0.0)
  {
    randvec_target_circle(xo, yo, zo, solid_angle,
               xi, yi, zi, 0);
    return;
  }
  else
  {
    /* Now choose point uniformly on rectangle within width x height */
    dx = width*randpm1()/2.0;
    dy = height*randpm1()/2.0;

    /* Determine distance to target plane*/
    dist = sqrt(xi*xi + yi*yi + zi*zi);
    /* Go to global coordinate system */

    tmp = coords_set(xi, yi, zi);
    tmp = rot_apply(Ainverse, tmp);
    coords_get(tmp, &xi, &yi, &zi);

    /* Determine vector normal to trajectory axis (z) and gravity [0 1 0] */
    vec_prod(nx, ny, nz, xi, yi, zi, 0, 1, 0);

    /* This now defines the x-axis, normalize: */
    n_norm=sqrt(nx*nx + ny*ny + nz*nz);
    nx = nx/n_norm;
    ny = ny/n_norm;
    nz = nz/n_norm;

    /* Now, determine our y-axis (vertical in many cases...) */
    vec_prod(mx, my, mz, xi, yi, zi, nx, ny, nz);
    m_norm=sqrt(mx*mx + my*my + mz*mz);
    mx = mx/m_norm;
    my = my/m_norm;
    mz = mz/m_norm;

    /* Our output, random vector can now be defined by linear combination: */

    *xo = xi + dx * nx + dy * mx;
    *yo = yi + dx * ny + dy * my;
    *zo = zi + dx * nz + dy * mz;

    /* Go back to local coordinate system */
    tmp = coords_set(*xo, *yo, *zo);
    tmp = rot_apply(A, tmp);
    coords_get(tmp, &*xo, &*yo, &*zo);

    /* Go back to local coordinate system */
    tmp = coords_set(xi, yi, zi);
    tmp = rot_apply(A, tmp);
    coords_get(tmp, &xi, &yi, &zi);

    if (solid_angle) {
      /* Calculate vector from local point to remote random point */
      lx = *xo - lx;
      ly = *yo - ly;
      lz = *zo - lz;
      dist_p = sqrt(lx*lx + ly*ly + lz*lz);

      /* Adjust the 'solid angle' */
      /* 1/r^2 to the chosen point times cos(\theta) between the normal */
      /* vector of the target rectangle and direction vector of the chosen point. */
      cos_theta = (xi * lx + yi * ly + zi * lz) / (dist * dist_p);
      *solid_angle = width * height / (dist_p * dist_p);
      int counter;
      for (counter = 0; counter < order; counter++) {
        *solid_angle = *solid_angle * cos_theta;
      }
    }
  }
}
/* randvec_target_rect_real */


/* SECTION: random numbers ==================================================

  How to add a new RNG:

  - Use an rng with a manegable state vector, e.g. of lengt 4 or 7. The state
  will sit on the particle struct as a "randstate_t state[RANDSTATE_LEN]"
  - If the rng has a long state (as MT), set an empty "srandom" and initialize
  it explicitly using the appropriate define (RNG_ALG)
  - Add a seed and a random function (the transforms will be reused)
  - Write the proper defines in mccode-r.h, e.g. randstate_t and RANDSTATE_LEN,
  srandom and random.
  - Compile using -DRNG_ALG=<selector int value>

============================================================================= */


/* "Mersenne Twister", by Makoto Matsumoto and Takuji Nishimura. */
/* See http://www.math.keio.ac.jp/~matumoto/emt.html for original source. */
/*
   A C-program for MT19937, with initialization improved 2002/1/26.
   Coded by Takuji Nishimura and Makoto Matsumoto.

   Before using, initialize the state by using mt_srandom(seed)
   or init_by_array(init_key, key_length).

   Copyright (C) 1997 - 2002, Makoto Matsumoto and Takuji Nishimura,
   All rights reserved.

   Redistribution and use in source and binary forms, with or without
   modification, are permitted provided that the following conditions
   are met:

     1. Redistributions of source code must retain the above copyright
        notice, this list of conditions and the following disclaimer.

     2. Redistributions in binary form must reproduce the above copyright
        notice, this list of conditions and the following disclaimer in the
        documentation and/or other materials provided with the distribution.

     3. The names of its contributors may not be used to endorse or promote
        products derived from this software without specific prior written
        permission.

   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
   CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
   EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
   PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
   PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
   LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.


   Any feedback is very welcome.
   http://www.math.keio.ac.jp/matumoto/emt.html
   email: matumoto@math.keio.ac.jp
*/
#include <stdio.h>
/* Period parameters */
#define N 624
#define M 397
#define MATRIX_A 0x9908b0dfUL   /* constant vector a */
#define UPPER_MASK 0x80000000UL /* most significant w-r bits */
#define LOWER_MASK 0x7fffffffUL /* least significant r bits */

unsigned long mt[N]; /* the array for the state vector  */
int mti=N+1; /* mti==N+1 means mt[N] is not initialized */

// required for common rng alg interface (see RNG_ALG usage in mccode-r.h)
void mt_srandom_empty() {}

// initializes mt[N] with a seed
void mt_srandom(unsigned long s)
{
    mt[0]= s & 0xffffffffUL;
    for (mti=1; mti<N; mti++) {
        mt[mti] =
            (1812433253UL * (mt[mti-1] ^ (mt[mti-1] >> 30)) + mti);
        /* See Knuth TAOCP Vol2. 3rd Ed. P.106 for multiplier. */
        /* In the previous versions, MSBs of the seed affect   */
        /* only MSBs of the array mt[].                        */
        /* 2002/01/09 modified by Makoto Matsumoto             */
        mt[mti] &= 0xffffffffUL;
        /* for >32 bit machines */
    }
}
/* Initialize by an array with array-length.
   Init_key is the array for initializing keys.
   key_length is its length. */
void init_by_array(unsigned long init_key[], unsigned long key_length)
{
    int i, j, k;
    mt_srandom(19650218UL);
    i=1; j=0;
    k = (N>key_length ? N : key_length);
    for (; k; k--) {
        mt[i] = (mt[i] ^ ((mt[i-1] ^ (mt[i-1] >> 30)) * 1664525UL))
          + init_key[j] + j; /* non linear */
        mt[i] &= 0xffffffffUL; /* for WORDSIZE > 32 machines */
        i++; j++;
        if (i>=N) { mt[0] = mt[N-1]; i=1; }
        if (j>=key_length) j=0;
    }
    for (k=N-1; k; k--) {
        mt[i] = (mt[i] ^ ((mt[i-1] ^ (mt[i-1] >> 30)) * 1566083941UL))
          - i; /* non linear */
        mt[i] &= 0xffffffffUL; /* for WORDSIZE > 32 machines */
        i++;
        if (i>=N) { mt[0] = mt[N-1]; i=1; }
    }

    mt[0] = 0x80000000UL; /* MSB is 1; assuring non-zero initial array */
}
/* generates a random number on [0,0xffffffff]-interval */
unsigned long mt_random(void)
{
    unsigned long y;
    unsigned long mag01[2]={0x0UL, MATRIX_A};
    /* mag01[x] = x * MATRIX_A  for x=0,1 */

    if (mti >= N) { /* generate N words at one time */
        int kk;

        if (mti == N+1)   /* if mt_srandom() has not been called, */
            mt_srandom(5489UL); /* a default initial seed is used */

        for (kk=0;kk<N-M;kk++) {
            y = (mt[kk]&UPPER_MASK)|(mt[kk+1]&LOWER_MASK);
            mt[kk] = mt[kk+M] ^ (y >> 1) ^ mag01[y & 0x1UL];
        }
        for (;kk<N-1;kk++) {
            y = (mt[kk]&UPPER_MASK)|(mt[kk+1]&LOWER_MASK);
            mt[kk] = mt[kk+(M-N)] ^ (y >> 1) ^ mag01[y & 0x1UL];
        }
        y = (mt[N-1]&UPPER_MASK)|(mt[0]&LOWER_MASK);
        mt[N-1] = mt[M-1] ^ (y >> 1) ^ mag01[y & 0x1UL];

        mti = 0;
    }

    y = mt[mti++];

    /* Tempering */
    y ^= (y >> 11);
    y ^= (y << 7) & 0x9d2c5680UL;
    y ^= (y << 15) & 0xefc60000UL;
    y ^= (y >> 18);

    return y;
}
#undef N
#undef M
#undef MATRIX_A
#undef UPPER_MASK
#undef LOWER_MASK
/* End of "Mersenne Twister". */


/*
KISS

 From: http://www.helsbreth.org/random/rng_kiss.html
 Scott Nelson 1999

 Based on Marsaglia's KISS or (KISS+SWB) <http://www.cs.yorku.ca/~oz/marsaglia-
rng.html>

 KISS - Keep it Simple Stupid PRNG

 the idea is to use simple, fast, individually promising
 generators to get a composite that will be fast, easy to code
 have a very long period and pass all the tests put to it.
 The three components of KISS are
        x(n)=a*x(n-1)+1 mod 2^32
        y(n)=y(n-1)(I+L^13)(I+R^17)(I+L^5),
        z(n)=2*z(n-1)+z(n-2) +carry mod 2^32
 The y's are a shift register sequence on 32bit binary vectors
 period 2^32-1;
 The z's are a simple multiply-with-carry sequence with period
 2^63+2^32-1.  The period of KISS is thus
      2^32*(2^32-1)*(2^63+2^32-1) > 2^127
*/

/* the KISS state is stored as a vector of 7 unsigned long        */
/*   0  1  2  3  4      5  6   */
/* [ x, y, z, w, carry, k, m ] */

unsigned long *kiss_srandom(unsigned long state[7], unsigned long seed) {
  if (seed == 0) seed = 1;
  state[0] = seed | 1; // x
  state[1] = seed | 2; // y
  state[2] = seed | 4; // z
  state[3] = seed | 8; // w
  state[4] = 0;        // carry
  return 0;
}

unsigned long kiss_random(unsigned long state[7]) {
    state[0] = state[0] * 69069 + 1;
    state[1] ^= state[1] << 13;
    state[1] ^= state[1] >> 17;
    state[1] ^= state[1] << 5;
    state[5] = (state[2] >> 2) + (state[3] >> 3) + (state[4] >> 2);
    state[6] = state[3] + state[3] + state[2] + state[4];
    state[2] = state[3];
    state[3] = state[6];
    state[4] = state[5] >> 30;
    return state[0] + state[1] + state[3];
}
/* end of "KISS" rng */


/* FAST KISS in another implementation (Hundt) */

//////////////////////////////////////////////////////////////////////////////
// fast keep it simple stupid generator
//////////////////////////////////////////////////////////////////////////////

/////////////////////////////////////////////////////////////////////////////
// Thomas Mueller hash for initialization of rngs
// http://stackoverflow.com/questions/664014/
//        what-integer-hash-function-are-good-that-accepts-an-integer-hash-key
//////////////////////////////////////////////////////////////////////////////
randstate_t _hash(randstate_t x) {
  x = ((x >> 16) ^ x) * 0x45d9f3b;
  x = ((x >> 16) ^ x) * 0x45d9f3b;
  x = ((x >> 16) ^ x);
  return x;
}


// SECTION: random number transforms ==========================================



// generate a random number from normal law
double _randnorm(randstate_t* state)
{
  static double v1, v2, s; /* removing static breaks comparison with McStas <= 2.5 */
  static int phase = 0;
  double X, u1, u2;

  if(phase == 0)
  {
    do
    {
      u1 = _rand01(state);
      u2 = _rand01(state);
      v1 = 2*u1 - 1;
      v2 = 2*u2 - 1;
      s = v1*v1 + v2*v2;
    } while(s >= 1 || s == 0);

    X = v1*sqrt(-2*log(s)/s);
  }
  else
  {
    X = v2*sqrt(-2*log(s)/s);
  }

  phase = 1 - phase;
  return X;
}
// another one
double _randnorm2(randstate_t* state) {
  double x, y, r;
  do {
      x = 2.0 * _rand01(state) - 1.0;
      y = 2.0 * _rand01(state) - 1.0;
      r = x*x + y*y;
  } while (r == 0.0 || r >= 1.0);
  return x * sqrt((-2.0 * log(r)) / r);
}

// Generate a random number from -1 to 1 with triangle distribution
double _randtriangle(randstate_t* state) {
	double randnum = _rand01(state);
	if (randnum>0.5) return(1-sqrt(2*(randnum-0.5)));
	else return(sqrt(2*randnum)-1);
}
double _rand01(randstate_t* state) {
	double randnum;
	randnum = (double) _random();
  // TODO: can we mult instead of div?
	randnum /= (double) MC_RAND_MAX + 1;
	return randnum;
}
// Return a random number between 1 and -1
double _randpm1(randstate_t* state) {
	double randnum;
	randnum = (double) _random();
	randnum /= ((double) MC_RAND_MAX + 1) / 2;
	randnum -= 1;
	return randnum;
}
// Return a random number between 0 and max.
double _rand0max(double max, randstate_t* state) {
	double randnum;
	randnum = (double) _random();
	randnum /= ((double) MC_RAND_MAX + 1) / max;
	return randnum;
}
// Return a random number between min and max.
double _randminmax(double min, double max, randstate_t* state) {
	return _rand0max(max - min, state) + max;
}


/* SECTION: main and signal handlers ======================================== */

/*******************************************************************************
* mchelp: displays instrument executable help with possible options
*******************************************************************************/
static void
mchelp(char *pgmname)
{
  int i;

  fprintf(stderr, "%s (%s) instrument simulation, generated with " MCCODE_STRING " (" MCCODE_DATE ")\n", instrument_name, instrument_source);
  fprintf(stderr, "Usage: %s [options] [parm=value ...]\n", pgmname);
  fprintf(stderr,
"Options are:\n"
"  -s SEED   --seed=SEED      Set random seed (must be != 0)\n"
"  -n COUNT  --ncount=COUNT   Set number of particles to simulate.\n"
"  -d DIR    --dir=DIR        Put all data files in directory DIR.\n"
"  -t        --trace          Enable trace of " MCCODE_PARTICLE "s through instrument.\n"
"                             (Use -t=2 or --trace=2 for modernised mcdisplay rendering)\n"
"  -g        --gravitation    Enable gravitation for all trajectories.\n"
"  --no-output-files          Do not write any data files.\n"
"  -h        --help           Show this help message.\n"
"  -i        --info           Detailed instrument information.\n"
"  --list-parameters          Print the instrument parameters to standard out\n"
"  --meta-list                Print names of components which defined metadata\n"
"  --meta-defined COMP[:NAME] Print component defined metadata names, or (0,1) if NAME provided\n"
"  --meta-type COMP:NAME      Print metadata format type specified in definition\n"
"  --meta-data COMP:NAME      Print the metadata text\n"
"  --source                   Show the instrument code which was compiled.\n"
#ifdef OPENACC
"\n"
"  --vecsize                  OpenACC vector-size (default: 128)\n"
"  --numgangs                 Number of OpenACC gangs (default: 7813)\n"
"  --gpu_innerloop            Maximum rays to process pr. OpenACC \n"
"                             kernel run (default: 2147483647)\n"
"\n"
#endif
"\n"
"  --bufsiz                   Monitor_nD list/buffer-size (default: 1000000)\n"
"  --format=FORMAT            Output data files using FORMAT="
   FLAVOR_UPPER
#ifdef USE_NEXUS
   " NEXUS\n"
"  --IDF                      Embed an xml-formatted IDF instrument definition\n"
"                             in the NeXus file (if existent in .)\n\n"
#else
"\n\n"
#endif
);
#ifdef USE_MPI
  fprintf(stderr,
  "This instrument has been compiled with MPI support.\n  Use 'mpirun %s [options] [parm=value ...]'.\n", pgmname);
#endif
#ifdef OPENACC
  fprintf(stderr,
  "This instrument has been compiled with NVIDIA GPU support through OpenACC.\n  Running on systems without such devices will lead to segfaults.\nFurter, fprintf, sprintf and printf have been removed from any component TRACE.\n");
#endif

  if(numipar > 0)
  {
    fprintf(stderr, "Instrument parameters are:\n");
    for(i = 0; i < numipar; i++)
      if (mcinputtable[i].val && strlen(mcinputtable[i].val))
        fprintf(stderr, "  %-16s(%s) [default='%s']\n", mcinputtable[i].name,
        (*mcinputtypes[mcinputtable[i].type].parminfo)(mcinputtable[i].name),
        mcinputtable[i].val);
      else
        fprintf(stderr, "  %-16s(%s)\n", mcinputtable[i].name,
        (*mcinputtypes[mcinputtable[i].type].parminfo)(mcinputtable[i].name));
  }

#ifndef NOSIGNALS
  fprintf(stderr, "Known signals are: "
#ifdef SIGUSR1
  "USR1 (status) "
#endif
#ifdef SIGUSR2
  "USR2 (save) "
#endif
#ifdef SIGBREAK
  "BREAK (save) "
#endif
#ifdef SIGTERM
  "TERM (save and exit)"
#endif
  "\n");
#endif /* !NOSIGNALS */
} /* mchelp */


/* mcshowhelp: show help and exit with 0 */
static void
mcshowhelp(char *pgmname)
{
  mchelp(pgmname);
  exit(0);
}

/* mcusage: display usage when error in input arguments and exit with 1 */
static void
mcusage(char *pgmname)
{
  fprintf(stderr, "Error: incorrect command line arguments\n");
  mchelp(pgmname);
  exit(1);
}

/* mcenabletrace: enable trace/mcdisplay or error if requires recompile */
static void
mcenabletrace(int mode)
{
 if(traceenabled) {
  mcdotrace = mode;
  #pragma acc update device ( mcdotrace )
 } else {
   fprintf(stderr,
           "Error: trace not enabled (mcenabletrace)\n"
           "Please re-run the " MCCODE_NAME " compiler "
                   "with the --trace option, or rerun the\n"
           "C compiler with the MC_TRACE_ENABLED macro defined.\n");
   exit(1);
 }
}

/*******************************************************************************
* mcreadparams: request parameters from the prompt (or use default)
*******************************************************************************/
void
mcreadparams(void)
{
  int i,j,status;
  static char buf[CHAR_BUF_LENGTH];
  char *p;
  int len;

  MPI_MASTER(printf("Instrument parameters for %s (%s)\n",
                    instrument_name, instrument_source));

  for(i = 0; mcinputtable[i].name != 0; i++)
  {
    do
    {
      MPI_MASTER(
                 if (mcinputtable[i].val && strlen(mcinputtable[i].val))
                   printf("Set value of instrument parameter %s (%s) [default='%s']:\n",
                          mcinputtable[i].name,
                          (*mcinputtypes[mcinputtable[i].type].parminfo)
                          (mcinputtable[i].name), mcinputtable[i].val);
                 else
                   printf("Set value of instrument parameter %s (%s):\n",
                          mcinputtable[i].name,
                          (*mcinputtypes[mcinputtable[i].type].parminfo)
                          (mcinputtable[i].name));
                 fflush(stdout);
                 );
#ifdef USE_MPI
      if(mpi_node_rank == mpi_node_root)
        {
          p = fgets(buf, CHAR_BUF_LENGTH, stdin);
          if(p == NULL)
            {
              fprintf(stderr, "Error: empty input for paramater %s (mcreadparams)\n", mcinputtable[i].name);
              exit(1);
            }
        }
      else
        p = buf;
      MPI_Bcast(buf, CHAR_BUF_LENGTH, MPI_CHAR, mpi_node_root, MPI_COMM_WORLD);
#else /* !USE_MPI */
      p = fgets(buf, CHAR_BUF_LENGTH, stdin);
      if(p == NULL)
        {
          fprintf(stderr, "Error: empty input for paramater %s (mcreadparams)\n", mcinputtable[i].name);
          exit(1);
        }
#endif /* USE_MPI */
      len = strlen(buf);
      if (!len || (len == 1 && (buf[0] == '\n' || buf[0] == '\r')))
      {
        if (mcinputtable[i].val && strlen(mcinputtable[i].val)) {
          strncpy(buf, mcinputtable[i].val, CHAR_BUF_LENGTH);  /* use default value */
          len = strlen(buf);
        }
      }
      for(j = 0; j < 2; j++)
      {
        if(len > 0 && (buf[len - 1] == '\n' || buf[len - 1] == '\r'))
        {
          len--;
          buf[len] = '\0';
        }
      }

      status = (*mcinputtypes[mcinputtable[i].type].getparm)
                   (buf, mcinputtable[i].par);
      if(!status)
      {
        (*mcinputtypes[mcinputtable[i].type].error)(mcinputtable[i].name, buf);
        if (!mcinputtable[i].val || strlen(mcinputtable[i].val)) {
          fprintf(stderr, "       Change %s default value in instrument definition.\n", mcinputtable[i].name);
          exit(1);
        }
      }
    } while(!status);
  }
} /* mcreadparams */

/*******************************************************************************
* mcparseoptions: parse command line arguments (options, parameters)
*******************************************************************************/
void
mcparseoptions(int argc, char *argv[])
{
  int i, j;
  char *p;
  int paramset = 0, *paramsetarray;
  char *usedir=NULL;

  /* Add one to numipar to avoid allocating zero size memory block. */
  paramsetarray = (int*)malloc((numipar + 1)*sizeof(*paramsetarray));
  if(paramsetarray == NULL)
  {
    fprintf(stderr, "Error: insufficient memory (mcparseoptions)\n");
    exit(1);
  }
  for(j = 0; j < numipar; j++)
    {
      paramsetarray[j] = 0;
      if (mcinputtable[j].val != NULL && strlen(mcinputtable[j].val))
      {
        int  status;
        char buf[CHAR_BUF_LENGTH];
        strncpy(buf, mcinputtable[j].val, CHAR_BUF_LENGTH);
        status = (*mcinputtypes[mcinputtable[j].type].getparm)
                   (buf, mcinputtable[j].par);
        if(!status) fprintf(stderr, "Invalid '%s' default value %s in instrument definition (mcparseoptions)\n", mcinputtable[j].name, buf);
        else paramsetarray[j] = 1;
      } else {
        (*mcinputtypes[mcinputtable[j].type].getparm)
          (NULL, mcinputtable[j].par);
        paramsetarray[j] = 0;
      }
    }
  for(i = 1; i < argc; i++)
  {
    if(!strcmp("-s", argv[i]) && (i + 1) < argc)
      mcsetseed(argv[++i]);
    else if(!strncmp("-s", argv[i], 2))
      mcsetseed(&argv[i][2]);
    else if(!strcmp("--seed", argv[i]) && (i + 1) < argc)
      mcsetseed(argv[++i]);
    else if(!strncmp("--seed=", argv[i], 7))
      mcsetseed(&argv[i][7]);
    else if(!strcmp("-n", argv[i]) && (i + 1) < argc)
      mcsetn_arg(argv[++i]);
    else if(!strncmp("-n", argv[i], 2))
      mcsetn_arg(&argv[i][2]);
    else if(!strcmp("--ncount", argv[i]) && (i + 1) < argc)
      mcsetn_arg(argv[++i]);
    else if(!strncmp("--ncount=", argv[i], 9))
      mcsetn_arg(&argv[i][9]);
    else if(!strcmp("-d", argv[i]) && (i + 1) < argc)
      usedir=argv[++i];  /* will create directory after parsing all arguments (end of this function) */
    else if(!strncmp("-d", argv[i], 2))
      usedir=&argv[i][2];
    else if(!strcmp("--dir", argv[i]) && (i + 1) < argc)
      usedir=argv[++i];
    else if(!strncmp("--dir=", argv[i], 6))
      usedir=&argv[i][6];
    else if(!strcmp("-h", argv[i]))
      mcshowhelp(argv[0]);
    else if(!strcmp("--help", argv[i]) || !strcmp("--version", argv[i]))
      mcshowhelp(argv[0]);
    else if(!strcmp("-i", argv[i])) {
      mcformat=FLAVOR_UPPER;
      mcinfo();
    }
    else if(!strcmp("--info", argv[i]))
      mcinfo();
    else if (!strcmp("--list-parameters", argv[i]))
      mcparameterinfo();
    else if (!strcmp("--meta-list", argv[i]) && ((i+1) >= argc || argv[i+1][0] == '-')){
      //printf("Components with metadata defined:\n");
      exit(metadata_table_print_all_components(num_metadata, metadata_table) == 0);
    }
    else if (!strcmp("--meta-defined", argv[i]) && (i+1) < argc){
      exit(metadata_table_print_component_keys(num_metadata, metadata_table, argv[i+1]) == 0);
    }
    else if (!strcmp("--meta-type", argv[i]) && (i+1) < argc){
      char * literal_type = metadata_table_type(num_metadata, metadata_table, argv[i+1]);
      if (literal_type == NULL) exit(1);
      printf("%s\n", literal_type);
      exit(0);
    }
    else if (!strcmp("--meta-data", argv[i]) && (i+1) < argc){
      char * literal = metadata_table_literal(num_metadata, metadata_table, argv[i+1]);
      if (literal == NULL) exit(1);
      printf("%s\n", literal);
      exit(0);
    }
    else if(!strncmp("--trace=", argv[i], 8)) {
      mcenabletrace(atoi(&argv[i][8]));
    } else if(!strncmp("-t=", argv[i], 3) || !strcmp("--verbose", argv[i])) {
      mcenabletrace(atoi(&argv[i][3]));
    } else if(!strcmp("-t", argv[i]))
      mcenabletrace(1);
    else if(!strcmp("--trace", argv[i]) || !strcmp("--verbose", argv[i]))
      mcenabletrace(1);
    else if(!strcmp("--gravitation", argv[i]))
      mcgravitation = 1;
    else if(!strcmp("-g", argv[i]))
      mcgravitation = 1;
    else if(!strncmp("--format=", argv[i], 9)) {
      mcformat=&argv[i][9];
    }
    else if(!strcmp("--format", argv[i]) && (i + 1) < argc) {
      mcformat=argv[++i];
    }
#ifdef USE_NEXUS
    else if(!strcmp("--IDF", argv[i])) {
      mcnexus_embed_idf = 1;
    }
#endif
    else if(!strncmp("--vecsize=", argv[i], 10)) {
      vecsize=atoi(&argv[i][10]);
    }    
    else if(!strcmp("--vecsize", argv[i]) && (i + 1) < argc) {
      vecsize=atoi(argv[++i]);
    }
    else if(!strncmp("--bufsiz=", argv[i], 9)) {
      MONND_BUFSIZ=atoi(&argv[i][9]);
    }
    else if(!strcmp("--bufsiz", argv[i]) && (i + 1) < argc) {
      MONND_BUFSIZ=atoi(argv[++i]);
    }
    else if(!strncmp("--numgangs=", argv[i], 11)) {
      numgangs=atoi(&argv[i][11]);
    }
    else if(!strcmp("--numgangs", argv[i]) && (i + 1) < argc) {
      numgangs=atoi(argv[++i]);
    }
    else if(!strncmp("--gpu_innerloop=", argv[i], 16)) {
      gpu_innerloop=(long)strtod(&argv[i][16], NULL);
    }
    else if(!strcmp("--gpu_innerloop", argv[i]) && (i + 1) < argc) {
      gpu_innerloop=(long)strtod(argv[++i], NULL);
    }

    else if(!strcmp("--no-output-files", argv[i]))
      mcdisable_output_files = 1;
    else if(!strcmp("--source", argv[i])) {
      printf("/* Source code %s from %s: */\n"
        "/******************************************************************************/\n"
        "%s\n"
        "/******************************************************************************/\n"
        "/* End of source code %s from %s */\n",
        instrument_name, instrument_source, instrument_code,
        instrument_name, instrument_source);
      exit(1);
    }
    else if(argv[i][0] != '-' && (p = strchr(argv[i], '=')) != NULL)
    {
      *p++ = '\0';

      for(j = 0; j < numipar; j++)
        if(!strcmp(mcinputtable[j].name, argv[i]))
        {
          int status;
          status = (*mcinputtypes[mcinputtable[j].type].getparm)(p,
                        mcinputtable[j].par);
          if(!status || !strlen(p))
          {
            (*mcinputtypes[mcinputtable[j].type].error)
              (mcinputtable[j].name, p);
            exit(1);
          }
          paramsetarray[j] = 1;
          paramset = 1;
          break;
        }
      if(j == numipar)
      {                                /* Unrecognized parameter name */
        fprintf(stderr, "Error: unrecognized parameter %s (mcparseoptions)\n", argv[i]);
        exit(1);
      }
    }
    else if(argv[i][0] == '-') {
      fprintf(stderr, "Error: unrecognized option argument %s (mcparseoptions). Ignored.\n", argv[i++]);
    }
    else {
      fprintf(stderr, "Error: unrecognized argument %s (mcparseoptions). Aborting.\n", argv[i]);
      mcusage(argv[0]);
    }
  }
  if(!paramset)
    mcreadparams();                /* Prompt for parameters if not specified. */
  else
  {
    for(j = 0; j < numipar; j++)
      if(!paramsetarray[j])
      {
        fprintf(stderr, "Error: Instrument parameter %s left unset (mcparseoptions)\n",
                mcinputtable[j].name);
        exit(1);
      }
  }
  free(paramsetarray);
#ifdef USE_MPI
  if (mcdotrace) mpi_node_count=1; /* disable threading when in trace mode */
#endif
  if (usedir && strlen(usedir) && !mcdisable_output_files) mcuse_dir(usedir);
} /* mcparseoptions */

#ifndef NOSIGNALS
/*******************************************************************************
* sighandler: signal handler that makes simulation stop, and save results
*******************************************************************************/
void sighandler(int sig)
{
  /* MOD: E. Farhi, Sep 20th 2001: give more info */
  time_t t1, t0;
#define SIG_SAVE 0
#define SIG_TERM 1
#define SIG_STAT 2
#define SIG_ABRT 3

  printf("\n# " MCCODE_STRING ": [pid %i] Signal %i detected", getpid(), sig);
#ifdef USE_MPI
  printf(" [proc %i]", mpi_node_rank);
#endif
#if defined(SIGUSR1) && defined(SIGUSR2) && defined(SIGKILL)
  if (!strcmp(mcsig_message, "sighandler") && (sig != SIGUSR1) && (sig != SIGUSR2))
  {
    printf("\n# Fatal : unrecoverable loop ! Suicide (naughty boy).\n");
    kill(0, SIGKILL); /* kill myself if error occurs within sighandler: loops */
  }
#endif
  switch (sig) {
#ifdef SIGINT
    case SIGINT : printf(" SIGINT (interrupt from terminal, Ctrl-C)"); sig = SIG_TERM; break;
#endif
#ifdef SIGILL
    case SIGILL  : printf(" SIGILL (Illegal instruction)"); sig = SIG_ABRT; break;
#endif
#ifdef SIGFPE
    case SIGFPE  : printf(" SIGFPE (Math Error)"); sig = SIG_ABRT; break;
#endif
#ifdef SIGSEGV
    case SIGSEGV : printf(" SIGSEGV (Mem Error)"); sig = SIG_ABRT; break;
#endif
#ifdef SIGTERM
    case SIGTERM : printf(" SIGTERM (Termination)"); sig = SIG_TERM; break;
#endif
#ifdef SIGABRT
    case SIGABRT : printf(" SIGABRT (Abort)"); sig = SIG_ABRT; break;
#endif
#ifdef SIGQUIT
    case SIGQUIT : printf(" SIGQUIT (Quit from terminal)"); sig = SIG_TERM; break;
#endif
#ifdef SIGTRAP
    case SIGTRAP : printf(" SIGTRAP (Trace trap)"); sig = SIG_ABRT; break;
#endif
#ifdef SIGPIPE
    case SIGPIPE : printf(" SIGPIPE (Broken pipe)"); sig = SIG_ABRT; break;
#endif
#ifdef SIGUSR1
    case SIGUSR1 : printf(" SIGUSR1 (Display info)"); sig = SIG_STAT; break;
#endif
#ifdef SIGUSR2
    case SIGUSR2 : printf(" SIGUSR2 (Save simulation)"); sig = SIG_SAVE; break;
#endif
#ifdef SIGHUP
    case SIGHUP  : printf(" SIGHUP (Hangup/update)"); sig = SIG_SAVE; break;
#endif
#ifdef SIGBUS
    case SIGBUS  : printf(" SIGBUS (Bus error)"); sig = SIG_ABRT; break;
#endif
#ifdef SIGURG
    case SIGURG  : printf(" SIGURG (Urgent socket condition)"); sig = SIG_ABRT; break;
#endif
#ifdef SIGBREAK
    case SIGBREAK: printf(" SIGBREAK (Break signal, Ctrl-Break)"); sig = SIG_SAVE; break;
#endif
    default : printf(" (look at signal list for signification)"); sig = SIG_ABRT; break;
  }
  printf("\n");
  printf("# Simulation: %s (%s) \n", instrument_name, instrument_source);
  printf("# Breakpoint: %s ", mcsig_message);
  if (strstr(mcsig_message, "Save") && (sig == SIG_SAVE))
    sig = SIG_STAT;
  SIG_MESSAGE("sighandler");
  if (mcget_ncount() == 0)
    printf("(0 %%)\n" );
  else
  {
    printf("%.2f %% (%10.1f/%10.1f)\n", 100.0*mcget_run_num()/mcget_ncount(), 1.0*mcget_run_num(), 1.0*mcget_ncount());
  }
  t0 = (time_t)mcstartdate;
  t1 = time(NULL);
  printf("# Date:      %s", ctime(&t1));
  printf("# Started:   %s", ctime(&t0));

  if (sig == SIG_STAT)
  {
    printf("# " MCCODE_STRING ": Resuming simulation (continue)\n");
    fflush(stdout);
    return;
  }
  else
  if (sig == SIG_SAVE)
  {
    printf("# " MCCODE_STRING ": Saving data and resume simulation (continue)\n");
    save(NULL);
    fflush(stdout);
    return;
  }
  else
  if (sig == SIG_TERM)
  {
    printf("# " MCCODE_STRING ": Finishing simulation (save results and exit)\n");
    finally();
    exit(0);
  }
  else
  {
    fflush(stdout);
    perror("# Last I/O Error");
    printf("# " MCCODE_STRING ": Simulation stop (abort).\n");
// This portion of the signal handling only works on UNIX
#if defined(__unix__) || defined(__APPLE__)
    signal(sig, SIG_DFL); /* force to use default sighandler now */
    kill(getpid(), sig);  /* and trigger it with the current signal */
#endif
    exit(-1);
  }
#undef SIG_SAVE
#undef SIG_TERM
#undef SIG_STAT
#undef SIG_ABRT

} /* sighandler */
#endif /* !NOSIGNALS */

#ifdef NEUTRONICS
/*Main neutronics function steers the McStas calls, initializes parameters etc */
/* Only called in case NEUTRONICS = TRUE */
void neutronics_main_(float *inx, float *iny, float *inz, float *invx, float *invy, float *invz, float *intime, float *insx, float *insy, float *insz, float *inw, float *outx, float *outy, float *outz, float *outvx, float *outvy, float *outvz, float *outtime, float *outsx, float *outsy, float *outsz, float *outwgt)
{

  extern double mcnx, mcny, mcnz, mcnvx, mcnvy, mcnvz;
  extern double mcnt, mcnsx, mcnsy, mcnsz, mcnp;

  /* External code governs iteration - McStas is iterated once per call to neutronics_main. I.e. below counter must be initiancated for each call to neutronics_main*/
  mcrun_num=0;

  time_t t;
  t = (time_t)mcstartdate;
  mcstartdate = t;  /* set start date before parsing options and creating sim file */
  init();

  /* *** parse options *** */
  SIG_MESSAGE("[" __FILE__ "] main START");
  mcformat=getenv(FLAVOR_UPPER "_FORMAT") ?
           getenv(FLAVOR_UPPER "_FORMAT") : FLAVOR_UPPER;

  /* Set neutron state based on input from neutronics code */
  mcsetstate(*inx,*iny,*inz,*invx,*invy,*invz,*intime,*insx,*insy,*insz,*inw);

  /* main neutron event loop - runs only one iteration */

  //mcstas_raytrace(&mcncount); /* prior to McStas 1.12 */

  mcallowbackprop = 1; //avoid absorbtion from negative dt
  int argc=1;
  char *argv[0];
  int dummy = mccode_main(argc, argv);

  *outx =  mcnx;
  *outy =  mcny;
  *outz =  mcnz;
  *outvx =  mcnvx;
  *outvy =  mcnvy;
  *outvz =  mcnvz;
  *outtime =  mcnt;
  *outsx =  mcnsx;
  *outsy =  mcnsy;
  *outsz =  mcnsz;
  *outwgt =  mcnp;

  return;
} /* neutronics_main */

#endif /*NEUTRONICS*/

#endif /* !MCCODE_H */
/* End of file "mccode-r.c". */
