Date: 2021-09-20T09:43:37+00:00

Actual source code: fncombine.c
slepc-3.15.2 2021-09-20
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      1: /*
      2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
      4:    Copyright (c) 2002-2021, 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: */
     10: /*
     11:    A function that is obtained by combining two other functions (either by
     12:    addition, multiplication, division or composition)

     14:       addition:          f(x) = f1(x)+f2(x)
     15:       multiplication:    f(x) = f1(x)*f2(x)
     16:       division:          f(x) = f1(x)/f2(x)      f(A) = f2(A)\f1(A)
     17:       composition:       f(x) = f2(f1(x))
     18: */

     20: #include <slepc/private/fnimpl.h>
     21: #include <slepcblaslapack.h>

     23: typedef struct {
     24:   FN            f1,f2;    /* functions */
     25:   FNCombineType comb;     /* how the functions are combined */
     26: } FN_COMBINE;

     28: PetscErrorCode FNEvaluateFunction_Combine(FN fn,PetscScalar x,PetscScalar *y)
     29: {
     31:   FN_COMBINE     *ctx = (FN_COMBINE*)fn->data;
     32:   PetscScalar    a,b;

     35:   FNEvaluateFunction(ctx->f1,x,&a);
     36:   switch (ctx->comb) {
     37:     case FN_COMBINE_ADD:
     38:       FNEvaluateFunction(ctx->f2,x,&b);
     39:       *y = a+b;
     40:       break;
     41:     case FN_COMBINE_MULTIPLY:
     42:       FNEvaluateFunction(ctx->f2,x,&b);
     43:       *y = a*b;
     44:       break;
     45:     case FN_COMBINE_DIVIDE:
     46:       FNEvaluateFunction(ctx->f2,x,&b);
     47:       if (b==0.0) SETERRQ(PETSC_COMM_SELF,1,"Function not defined in the requested value");
     48:       *y = a/b;
     49:       break;
     50:     case FN_COMBINE_COMPOSE:
     51:       FNEvaluateFunction(ctx->f2,a,y);
     52:       break;
     53:   }
     54:   return(0);
     55: }

     57: PetscErrorCode FNEvaluateDerivative_Combine(FN fn,PetscScalar x,PetscScalar *yp)
     58: {
     60:   FN_COMBINE     *ctx = (FN_COMBINE*)fn->data;
     61:   PetscScalar    a,b,ap,bp;

     64:   switch (ctx->comb) {
     65:     case FN_COMBINE_ADD:
     66:       FNEvaluateDerivative(ctx->f1,x,&ap);
     67:       FNEvaluateDerivative(ctx->f2,x,&bp);
     68:       *yp = ap+bp;
     69:       break;
     70:     case FN_COMBINE_MULTIPLY:
     71:       FNEvaluateDerivative(ctx->f1,x,&ap);
     72:       FNEvaluateDerivative(ctx->f2,x,&bp);
     73:       FNEvaluateFunction(ctx->f1,x,&a);
     74:       FNEvaluateFunction(ctx->f2,x,&b);
     75:       *yp = ap*b+a*bp;
     76:       break;
     77:     case FN_COMBINE_DIVIDE:
     78:       FNEvaluateDerivative(ctx->f1,x,&ap);
     79:       FNEvaluateDerivative(ctx->f2,x,&bp);
     80:       FNEvaluateFunction(ctx->f1,x,&a);
     81:       FNEvaluateFunction(ctx->f2,x,&b);
     82:       if (b==0.0) SETERRQ(PETSC_COMM_SELF,1,"Derivative not defined in the requested value");
     83:       *yp = (ap*b-a*bp)/(b*b);
     84:       break;
     85:     case FN_COMBINE_COMPOSE:
     86:       FNEvaluateFunction(ctx->f1,x,&a);
     87:       FNEvaluateDerivative(ctx->f1,x,&ap);
     88:       FNEvaluateDerivative(ctx->f2,a,yp);
     89:       *yp *= ap;
     90:       break;
     91:   }
     92:   return(0);
     93: }

     95: PetscErrorCode FNEvaluateFunctionMat_Combine(FN fn,Mat A,Mat B)
     96: {
     97:   PetscErrorCode    ierr;
     98:   FN_COMBINE        *ctx = (FN_COMBINE*)fn->data;
     99:   PetscScalar       *Ba,*Wa,one=1.0,zero=0.0;
    100:   const PetscScalar *Za;
    101:   PetscBLASInt      n,ld,ld2,inc=1,*ipiv,info;
    102:   PetscInt          m;
    103:   Mat               W,Z;

    106:   FN_AllocateWorkMat(fn,A,&W);
    107:   MatGetSize(A,&m,NULL);
    108:   PetscBLASIntCast(m,&n);
    109:   ld  = n;
    110:   ld2 = ld*ld;

    112:   switch (ctx->comb) {
    113:     case FN_COMBINE_ADD:
    114:       FNEvaluateFunctionMat_Private(ctx->f1,A,W,PETSC_FALSE);
    115:       FNEvaluateFunctionMat_Private(ctx->f2,A,B,PETSC_FALSE);
    116:       MatDenseGetArray(B,&Ba);
    117:       MatDenseGetArray(W,&Wa);
    118:       PetscStackCallBLAS("BLASaxpy",BLASaxpy_(&ld2,&one,Wa,&inc,Ba,&inc));
    119:       PetscLogFlops(1.0*n*n);
    120:       MatDenseRestoreArray(B,&Ba);
    121:       MatDenseRestoreArray(W,&Wa);
    122:       break;
    123:     case FN_COMBINE_MULTIPLY:
    124:       FN_AllocateWorkMat(fn,A,&Z);
    125:       FNEvaluateFunctionMat_Private(ctx->f1,A,W,PETSC_FALSE);
    126:       FNEvaluateFunctionMat_Private(ctx->f2,A,Z,PETSC_FALSE);
    127:       MatDenseGetArray(B,&Ba);
    128:       MatDenseGetArray(W,&Wa);
    129:       MatDenseGetArrayRead(Z,&Za);
    130:       PetscStackCallBLAS("BLASgemm",BLASgemm_("N","N",&n,&n,&n,&one,Wa,&ld,Za,&ld,&zero,Ba,&ld));
    131:       PetscLogFlops(2.0*n*n*n);
    132:       MatDenseRestoreArray(B,&Ba);
    133:       MatDenseRestoreArray(W,&Wa);
    134:       MatDenseRestoreArrayRead(Z,&Za);
    135:       FN_FreeWorkMat(fn,&Z);
    136:       break;
    137:     case FN_COMBINE_DIVIDE:
    138:       FNEvaluateFunctionMat_Private(ctx->f2,A,W,PETSC_FALSE);
    139:       FNEvaluateFunctionMat_Private(ctx->f1,A,B,PETSC_FALSE);
    140:       PetscMalloc1(ld,&ipiv);
    141:       MatDenseGetArray(B,&Ba);
    142:       MatDenseGetArray(W,&Wa);
    143:       PetscStackCallBLAS("LAPACKgesv",LAPACKgesv_(&n,&n,Wa,&ld,ipiv,Ba,&ld,&info));
    144:       SlepcCheckLapackInfo("gesv",info);
    145:       PetscLogFlops(2.0*n*n*n/3.0+2.0*n*n*n);
    146:       MatDenseRestoreArray(B,&Ba);
    147:       MatDenseRestoreArray(W,&Wa);
    148:       PetscFree(ipiv);
    149:       break;
    150:     case FN_COMBINE_COMPOSE:
    151:       FNEvaluateFunctionMat_Private(ctx->f1,A,W,PETSC_FALSE);
    152:       FNEvaluateFunctionMat_Private(ctx->f2,W,B,PETSC_FALSE);
    153:       break;
    154:   }

    156:   FN_FreeWorkMat(fn,&W);
    157:   return(0);
    158: }

    160: PetscErrorCode FNEvaluateFunctionMatVec_Combine(FN fn,Mat A,Vec v)
    161: {
    163:   FN_COMBINE     *ctx = (FN_COMBINE*)fn->data;
    164:   PetscScalar    *va,*Za;
    165:   PetscBLASInt   n,ld,*ipiv,info,one=1;
    166:   PetscInt       m;
    167:   Mat            Z;
    168:   Vec            w;

    171:   MatGetSize(A,&m,NULL);
    172:   PetscBLASIntCast(m,&n);
    173:   ld = n;

    175:   switch (ctx->comb) {
    176:     case FN_COMBINE_ADD:
    177:       VecDuplicate(v,&w);
    178:       FNEvaluateFunctionMatVec(ctx->f1,A,w);
    179:       FNEvaluateFunctionMatVec(ctx->f2,A,v);
    180:       VecAXPY(v,1.0,w);
    181:       VecDestroy(&w);
    182:       break;
    183:     case FN_COMBINE_MULTIPLY:
    184:       VecDuplicate(v,&w);
    185:       FN_AllocateWorkMat(fn,A,&Z);
    186:       FNEvaluateFunctionMat_Private(ctx->f1,A,Z,PETSC_FALSE);
    187:       FNEvaluateFunctionMatVec_Private(ctx->f2,A,w,PETSC_FALSE);
    188:       MatMult(Z,w,v);
    189:       FN_FreeWorkMat(fn,&Z);
    190:       VecDestroy(&w);
    191:       break;
    192:     case FN_COMBINE_DIVIDE:
    193:       VecDuplicate(v,&w);
    194:       FN_AllocateWorkMat(fn,A,&Z);
    195:       FNEvaluateFunctionMat_Private(ctx->f2,A,Z,PETSC_FALSE);
    196:       FNEvaluateFunctionMatVec_Private(ctx->f1,A,v,PETSC_FALSE);
    197:       PetscMalloc1(ld,&ipiv);
    198:       MatDenseGetArray(Z,&Za);
    199:       VecGetArray(v,&va);
    200:       PetscStackCallBLAS("LAPACKgesv",LAPACKgesv_(&n,&one,Za,&ld,ipiv,va,&ld,&info));
    201:       SlepcCheckLapackInfo("gesv",info);
    202:       PetscLogFlops(2.0*n*n*n/3.0+2.0*n*n);
    203:       VecRestoreArray(v,&va);
    204:       MatDenseRestoreArray(Z,&Za);
    205:       PetscFree(ipiv);
    206:       FN_FreeWorkMat(fn,&Z);
    207:       VecDestroy(&w);
    208:       break;
    209:     case FN_COMBINE_COMPOSE:
    210:       FN_AllocateWorkMat(fn,A,&Z);
    211:       FNEvaluateFunctionMat_Private(ctx->f1,A,Z,PETSC_FALSE);
    212:       FNEvaluateFunctionMatVec_Private(ctx->f2,Z,v,PETSC_FALSE);
    213:       FN_FreeWorkMat(fn,&Z);
    214:       break;
    215:   }
    216:   return(0);
    217: }

    219: PetscErrorCode FNView_Combine(FN fn,PetscViewer viewer)
    220: {
    222:   FN_COMBINE     *ctx = (FN_COMBINE*)fn->data;
    223:   PetscBool      isascii;

    226:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&isascii);
    227:   if (isascii) {
    228:     switch (ctx->comb) {
    229:       case FN_COMBINE_ADD:
    230:         PetscViewerASCIIPrintf(viewer,"  Two added functions f1+f2\n");
    231:         break;
    232:       case FN_COMBINE_MULTIPLY:
    233:         PetscViewerASCIIPrintf(viewer,"  Two multiplied functions f1*f2\n");
    234:         break;
    235:       case FN_COMBINE_DIVIDE:
    236:         PetscViewerASCIIPrintf(viewer,"  A quotient of two functions f1/f2\n");
    237:         break;
    238:       case FN_COMBINE_COMPOSE:
    239:         PetscViewerASCIIPrintf(viewer,"  Two composed functions f2(f1(.))\n");
    240:         break;
    241:     }
    242:     PetscViewerASCIIPushTab(viewer);
    243:     FNView(ctx->f1,viewer);
    244:     FNView(ctx->f2,viewer);
    245:     PetscViewerASCIIPopTab(viewer);
    246:   }
    247:   return(0);
    248: }

    250: static PetscErrorCode FNCombineSetChildren_Combine(FN fn,FNCombineType comb,FN f1,FN f2)
    251: {
    253:   FN_COMBINE     *ctx = (FN_COMBINE*)fn->data;

    256:   ctx->comb = comb;
    257:   PetscObjectReference((PetscObject)f1);
    258:   FNDestroy(&ctx->f1);
    259:   ctx->f1 = f1;
    260:   PetscLogObjectParent((PetscObject)fn,(PetscObject)ctx->f1);
    261:   PetscObjectReference((PetscObject)f2);
    262:   FNDestroy(&ctx->f2);
    263:   ctx->f2 = f2;
    264:   PetscLogObjectParent((PetscObject)fn,(PetscObject)ctx->f2);
    265:   return(0);
    266: }

    268: /*@
    269:    FNCombineSetChildren - Sets the two child functions that constitute this
    270:    combined function, and the way they must be combined.

    272:    Logically Collective on fn

    274:    Input Parameters:
    275: +  fn   - the math function context
    276: .  comb - how to combine the functions (addition, multiplication, division or composition)
    277: .  f1   - first function
    278: -  f2   - second function

    280:    Level: intermediate

    282: .seealso: FNCombineGetChildren()
    283: @*/
    284: PetscErrorCode FNCombineSetChildren(FN fn,FNCombineType comb,FN f1,FN f2)
    285: {

    293:   PetscTryMethod(fn,"FNCombineSetChildren_C",(FN,FNCombineType,FN,FN),(fn,comb,f1,f2));
    294:   return(0);
    295: }

    297: static PetscErrorCode FNCombineGetChildren_Combine(FN fn,FNCombineType *comb,FN *f1,FN *f2)
    298: {
    300:   FN_COMBINE     *ctx = (FN_COMBINE*)fn->data;

    303:   if (comb) *comb = ctx->comb;
    304:   if (f1) {
    305:     if (!ctx->f1) {
    306:       FNCreate(PetscObjectComm((PetscObject)fn),&ctx->f1);
    307:       PetscLogObjectParent((PetscObject)fn,(PetscObject)ctx->f1);
    308:     }
    309:     *f1 = ctx->f1;
    310:   }
    311:   if (f2) {
    312:     if (!ctx->f2) {
    313:       FNCreate(PetscObjectComm((PetscObject)fn),&ctx->f2);
    314:       PetscLogObjectParent((PetscObject)fn,(PetscObject)ctx->f2);
    315:     }
    316:     *f2 = ctx->f2;
    317:   }
    318:   return(0);
    319: }

    321: /*@
    322:    FNCombineGetChildren - Gets the two child functions that constitute this
    323:    combined function, and the way they are combined.

    325:    Not Collective

    327:    Input Parameter:
    328: .  fn   - the math function context

    330:    Output Parameters:
    331: +  comb - how to combine the functions (addition, multiplication, division or composition)
    332: .  f1   - first function
    333: -  f2   - second function

    335:    Level: intermediate

    337: .seealso: FNCombineSetChildren()
    338: @*/
    339: PetscErrorCode FNCombineGetChildren(FN fn,FNCombineType *comb,FN *f1,FN *f2)
    340: {

    345:   PetscUseMethod(fn,"FNCombineGetChildren_C",(FN,FNCombineType*,FN*,FN*),(fn,comb,f1,f2));
    346:   return(0);
    347: }

    349: PetscErrorCode FNDuplicate_Combine(FN fn,MPI_Comm comm,FN *newfn)
    350: {
    352:   FN_COMBINE     *ctx = (FN_COMBINE*)fn->data,*ctx2 = (FN_COMBINE*)(*newfn)->data;

    355:   ctx2->comb = ctx->comb;
    356:   FNDuplicate(ctx->f1,comm,&ctx2->f1);
    357:   FNDuplicate(ctx->f2,comm,&ctx2->f2);
    358:   return(0);
    359: }

    361: PetscErrorCode FNDestroy_Combine(FN fn)
    362: {
    364:   FN_COMBINE     *ctx = (FN_COMBINE*)fn->data;

    367:   FNDestroy(&ctx->f1);
    368:   FNDestroy(&ctx->f2);
    369:   PetscFree(fn->data);
    370:   PetscObjectComposeFunction((PetscObject)fn,"FNCombineSetChildren_C",NULL);
    371:   PetscObjectComposeFunction((PetscObject)fn,"FNCombineGetChildren_C",NULL);
    372:   return(0);
    373: }

    375: SLEPC_EXTERN PetscErrorCode FNCreate_Combine(FN fn)
    376: {
    378:   FN_COMBINE     *ctx;

    381:   PetscNewLog(fn,&ctx);
    382:   fn->data = (void*)ctx;

    384:   fn->ops->evaluatefunction          = FNEvaluateFunction_Combine;
    385:   fn->ops->evaluatederivative        = FNEvaluateDerivative_Combine;
    386:   fn->ops->evaluatefunctionmat[0]    = FNEvaluateFunctionMat_Combine;
    387:   fn->ops->evaluatefunctionmatvec[0] = FNEvaluateFunctionMatVec_Combine;
    388:   fn->ops->view                      = FNView_Combine;
    389:   fn->ops->duplicate                 = FNDuplicate_Combine;
    390:   fn->ops->destroy                   = FNDestroy_Combine;
    391:   PetscObjectComposeFunction((PetscObject)fn,"FNCombineSetChildren_C",FNCombineSetChildren_Combine);
    392:   PetscObjectComposeFunction((PetscObject)fn,"FNCombineGetChildren_C",FNCombineGetChildren_Combine);
    393:   return(0);
    394: }