Date: 2021-02-01T14:41:40+00:00

Actual source code: fncombine.c
slepc-3.14.2 2021-02-01
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      1: /*
      2:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
      3:    SLEPc - Scalable Library for Eigenvalue Problem Computations
      4:    Copyright (c) 2002-2020, 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: {
     98:   FN_COMBINE     *ctx = (FN_COMBINE*)fn->data;
     99:   PetscScalar    *Aa,*Ba,*Wa,*Za,one=1.0,zero=0.0;
    100:   PetscBLASInt   n,ld,ld2,inc=1,*ipiv,info;
    101:   PetscInt       m;
    102:   Mat            W,Z;

    105:   FN_AllocateWorkMat(fn,A,&W);
    106:   MatDenseGetArray(A,&Aa);
    107:   MatDenseGetArray(B,&Ba);
    108:   MatDenseGetArray(W,&Wa);
    109:   MatGetSize(A,&m,NULL);
    110:   PetscBLASIntCast(m,&n);
    111:   ld  = n;
    112:   ld2 = ld*ld;

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

    146:   MatDenseRestoreArray(A,&Aa);
    147:   MatDenseRestoreArray(B,&Ba);
    148:   MatDenseRestoreArray(W,&Wa);
    149:   FN_FreeWorkMat(fn,&W);
    150:   return(0);
    151: }

    153: PetscErrorCode FNEvaluateFunctionMatVec_Combine(FN fn,Mat A,Vec v)
    154: {
    156:   FN_COMBINE     *ctx = (FN_COMBINE*)fn->data;
    157:   PetscScalar    *va,*Za;
    158:   PetscBLASInt   n,ld,*ipiv,info,one=1;
    159:   PetscInt       m;
    160:   Mat            Z;
    161:   Vec            w;

    164:   MatGetSize(A,&m,NULL);
    165:   PetscBLASIntCast(m,&n);
    166:   ld = n;

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

    212: PetscErrorCode FNView_Combine(FN fn,PetscViewer viewer)
    213: {
    215:   FN_COMBINE     *ctx = (FN_COMBINE*)fn->data;
    216:   PetscBool      isascii;

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

    243: static PetscErrorCode FNCombineSetChildren_Combine(FN fn,FNCombineType comb,FN f1,FN f2)
    244: {
    246:   FN_COMBINE     *ctx = (FN_COMBINE*)fn->data;

    249:   ctx->comb = comb;
    250:   PetscObjectReference((PetscObject)f1);
    251:   FNDestroy(&ctx->f1);
    252:   ctx->f1 = f1;
    253:   PetscLogObjectParent((PetscObject)fn,(PetscObject)ctx->f1);
    254:   PetscObjectReference((PetscObject)f2);
    255:   FNDestroy(&ctx->f2);
    256:   ctx->f2 = f2;
    257:   PetscLogObjectParent((PetscObject)fn,(PetscObject)ctx->f2);
    258:   return(0);
    259: }

    261: /*@
    262:    FNCombineSetChildren - Sets the two child functions that constitute this
    263:    combined function, and the way they must be combined.

    265:    Logically Collective on fn

    267:    Input Parameters:
    268: +  fn   - the math function context
    269: .  comb - how to combine the functions (addition, multiplication, division or composition)
    270: .  f1   - first function
    271: -  f2   - second function

    273:    Level: intermediate

    275: .seealso: FNCombineGetChildren()
    276: @*/
    277: PetscErrorCode FNCombineSetChildren(FN fn,FNCombineType comb,FN f1,FN f2)
    278: {

    286:   PetscTryMethod(fn,"FNCombineSetChildren_C",(FN,FNCombineType,FN,FN),(fn,comb,f1,f2));
    287:   return(0);
    288: }

    290: static PetscErrorCode FNCombineGetChildren_Combine(FN fn,FNCombineType *comb,FN *f1,FN *f2)
    291: {
    293:   FN_COMBINE     *ctx = (FN_COMBINE*)fn->data;

    296:   if (comb) *comb = ctx->comb;
    297:   if (f1) {
    298:     if (!ctx->f1) {
    299:       FNCreate(PetscObjectComm((PetscObject)fn),&ctx->f1);
    300:       PetscLogObjectParent((PetscObject)fn,(PetscObject)ctx->f1);
    301:     }
    302:     *f1 = ctx->f1;
    303:   }
    304:   if (f2) {
    305:     if (!ctx->f2) {
    306:       FNCreate(PetscObjectComm((PetscObject)fn),&ctx->f2);
    307:       PetscLogObjectParent((PetscObject)fn,(PetscObject)ctx->f2);
    308:     }
    309:     *f2 = ctx->f2;
    310:   }
    311:   return(0);
    312: }

    314: /*@
    315:    FNCombineGetChildren - Gets the two child functions that constitute this
    316:    combined function, and the way they are combined.

    318:    Not Collective

    320:    Input Parameter:
    321: .  fn   - the math function context

    323:    Output Parameters:
    324: +  comb - how to combine the functions (addition, multiplication, division or composition)
    325: .  f1   - first function
    326: -  f2   - second function

    328:    Level: intermediate

    330: .seealso: FNCombineSetChildren()
    331: @*/
    332: PetscErrorCode FNCombineGetChildren(FN fn,FNCombineType *comb,FN *f1,FN *f2)
    333: {

    338:   PetscUseMethod(fn,"FNCombineGetChildren_C",(FN,FNCombineType*,FN*,FN*),(fn,comb,f1,f2));
    339:   return(0);
    340: }

    342: PetscErrorCode FNDuplicate_Combine(FN fn,MPI_Comm comm,FN *newfn)
    343: {
    345:   FN_COMBINE     *ctx = (FN_COMBINE*)fn->data,*ctx2 = (FN_COMBINE*)(*newfn)->data;

    348:   ctx2->comb = ctx->comb;
    349:   FNDuplicate(ctx->f1,comm,&ctx2->f1);
    350:   FNDuplicate(ctx->f2,comm,&ctx2->f2);
    351:   return(0);
    352: }

    354: PetscErrorCode FNDestroy_Combine(FN fn)
    355: {
    357:   FN_COMBINE     *ctx = (FN_COMBINE*)fn->data;

    360:   FNDestroy(&ctx->f1);
    361:   FNDestroy(&ctx->f2);
    362:   PetscFree(fn->data);
    363:   PetscObjectComposeFunction((PetscObject)fn,"FNCombineSetChildren_C",NULL);
    364:   PetscObjectComposeFunction((PetscObject)fn,"FNCombineGetChildren_C",NULL);
    365:   return(0);
    366: }

    368: SLEPC_EXTERN PetscErrorCode FNCreate_Combine(FN fn)
    369: {
    371:   FN_COMBINE     *ctx;

    374:   PetscNewLog(fn,&ctx);
    375:   fn->data = (void*)ctx;

    377:   fn->ops->evaluatefunction          = FNEvaluateFunction_Combine;
    378:   fn->ops->evaluatederivative        = FNEvaluateDerivative_Combine;
    379:   fn->ops->evaluatefunctionmat[0]    = FNEvaluateFunctionMat_Combine;
    380:   fn->ops->evaluatefunctionmatvec[0] = FNEvaluateFunctionMatVec_Combine;
    381:   fn->ops->view                      = FNView_Combine;
    382:   fn->ops->duplicate                 = FNDuplicate_Combine;
    383:   fn->ops->destroy                   = FNDestroy_Combine;
    384:   PetscObjectComposeFunction((PetscObject)fn,"FNCombineSetChildren_C",FNCombineSetChildren_Combine);
    385:   PetscObjectComposeFunction((PetscObject)fn,"FNCombineGetChildren_C",FNCombineGetChildren_Combine);
    386:   return(0);
    387: }