Date: 2026-01-20T11:35:26+00:00

Actual source code: test18.c

      1: /*
      2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
      4:    Copyright (c) 2002-, Universitat Politecnica de Valencia, Spain

      6:    This file is part of SLEPc.
      7:    SLEPc is distributed under a 2-clause BSD license (see LICENSE).
      8:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      9: */

     11: static char help[] = "Test DSSynchronize() on a NHEP.\n\n";

     13: #include <slepcds.h>

     15: PetscErrorCode CheckArray(PetscScalar *A,const char *label,PetscInt k)
     16: {
     17:   PetscInt       j;
     18:   PetscMPIInt    p,size,rank,k_;
     19:   PetscScalar    dif,*buf;
     20:   PetscReal      error;

     22:   PetscFunctionBeginUser;
     23:   PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD,&size));
     24:   PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD,&rank));
     25:   PetscCall(PetscMPIIntCast(k,&k_));
     26:   if (rank) PetscCallMPI(MPI_Send(A,k_,MPIU_SCALAR,0,111,PETSC_COMM_WORLD));
     27:   else {
     28:     PetscCall(PetscMalloc1(k,&buf));
     29:     for (p=1;p<size;p++) {
     30:       PetscCallMPI(MPI_Recv(buf,k_,MPIU_SCALAR,p,111,PETSC_COMM_WORLD,MPI_STATUS_IGNORE));
     31:       dif = 0.0;
     32:       for (j=0;j<k;j++) dif += A[j]-buf[j];
     33:       error = PetscAbsScalar(dif);
     34:       if (error>10*PETSC_MACHINE_EPSILON) PetscCall(PetscPrintf(PETSC_COMM_WORLD," Array %s differs in proc %d: %g\n",label,(int)p,(double)error));
     35:     }
     36:     PetscCall(PetscFree(buf));
     37:   }
     38:   PetscFunctionReturn(PETSC_SUCCESS);
     39: }

     41: int main(int argc,char **argv)
     42: {
     43:   DS             ds;
     44:   SlepcSC        sc;
     45:   PetscScalar    *A,*Q,*wr,*wi;
     46:   PetscReal      re,im;
     47:   PetscInt       i,j,n=10;
     48:   PetscMPIInt    size;

     50:   PetscFunctionBeginUser;
     51:   PetscCall(SlepcInitialize(&argc,&argv,NULL,help));
     52:   PetscCall(PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL));
     53:   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"Solve a Dense System of type NHEP - dimension %" PetscInt_FMT ".\n",n));

     55:   /* Create DS object */
     56:   PetscCall(DSCreate(PETSC_COMM_WORLD,&ds));
     57:   PetscCall(DSSetType(ds,DSNHEP));
     58:   PetscCall(DSSetFromOptions(ds));
     59:   PetscCall(DSAllocate(ds,n));
     60:   PetscCall(DSSetDimensions(ds,n,0,0));

     62:   /* Fill with Grcar matrix */
     63:   PetscCall(DSGetArray(ds,DS_MAT_A,&A));
     64:   for (i=1;i<n;i++) A[i+(i-1)*n]=-1.0;
     65:   for (j=0;j<4;j++) {
     66:     for (i=0;i<n-j;i++) A[i+(i+j)*n]=1.0;
     67:   }
     68:   PetscCall(DSRestoreArray(ds,DS_MAT_A,&A));
     69:   PetscCall(DSSetState(ds,DS_STATE_INTERMEDIATE));

     71:   /* Solve */
     72:   PetscCall(PetscMalloc2(n,&wr,n,&wi));
     73:   PetscCall(DSGetSlepcSC(ds,&sc));
     74:   sc->comparison    = SlepcCompareLargestMagnitude;
     75:   sc->comparisonctx = NULL;
     76:   sc->map           = NULL;
     77:   sc->mapobj        = NULL;
     78:   PetscCall(DSSolve(ds,wr,wi));
     79:   PetscCall(DSSort(ds,wr,wi,NULL,NULL,NULL));

     81:   /* Print eigenvalues */
     82:   PetscCall(PetscPrintf(PETSC_COMM_WORLD,"Computed eigenvalues =\n"));
     83:   for (i=0;i<n;i++) {
     84: #if defined(PETSC_USE_COMPLEX)
     85:     re = PetscRealPart(wr[i]);
     86:     im = PetscImaginaryPart(wr[i]);
     87: #else
     88:     re = wr[i];
     89:     im = wi[i];
     90: #endif
     91:     if (PetscAbs(im)<1e-10) PetscCall(PetscPrintf(PETSC_COMM_WORLD,"  %.5f\n",(double)re));
     92:     else PetscCall(PetscPrintf(PETSC_COMM_WORLD,"  %.5f%+.5fi\n",(double)re,(double)im));
     93:   }

     95:   /* Synchronize data and check */
     96:   PetscCall(DSSynchronize(ds,wr,wi));
     97:   PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD,&size));
     98:   if (size>1) {
     99:     PetscCall(CheckArray(wr,"wr",n));
    100: #if !defined(PETSC_USE_COMPLEX)
    101:     PetscCall(CheckArray(wi,"wi",n));
    102: #endif
    103:     PetscCall(DSGetArray(ds,DS_MAT_A,&A));
    104:     PetscCall(CheckArray(A,"A",n*n));
    105:     PetscCall(DSRestoreArray(ds,DS_MAT_A,&A));
    106:     PetscCall(DSGetArray(ds,DS_MAT_Q,&Q));
    107:     PetscCall(CheckArray(Q,"Q",n*n));
    108:     PetscCall(DSRestoreArray(ds,DS_MAT_Q,&Q));
    109:   }

    111:   PetscCall(PetscFree2(wr,wi));
    112:   PetscCall(DSDestroy(&ds));
    113:   PetscCall(SlepcFinalize());
    114:   return 0;
    115: }

    117: /*TEST

    119:    testset:
    120:       nsize: {{1 2 3}}
    121:       filter: sed -e "s/[+-]\([0-9]\.[0-9]*i\)/+-\\1/" | sed -e "s/1.58254/1.58255/" | sed -e "s/1.75989/1.75988/" | sed -e "s/1.01945/1.01946/"
    122:       output_file: output/test18_1.out
    123:       test:
    124:          suffix: 1
    125:          args: -ds_parallel redundant
    126:       test:
    127:          suffix: 2
    128:          args: -ds_parallel synchronized

    130: TEST*/