Date: 2023-09-05T10:18:14+00:00

Actual source code: nepdefl.c
slepc-3.19.2 2023-09-05
Report Typos and Errors

      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: #include <slepc/private/nepimpl.h>
     12: #include <slepcblaslapack.h>
     13: #include "nepdefl.h"

     15: PetscErrorCode NEPDeflationGetInvariantPair(NEP_EXT_OP extop,BV *X,Mat *H)
     16: {
     17:   PetscFunctionBegin;
     18:   if (X) *X = extop->X;
     19:   if (H) PetscCall(MatCreateSeqDense(PETSC_COMM_SELF,extop->szd+1,extop->szd+1,extop->H,H));
     20:   PetscFunctionReturn(PETSC_SUCCESS);
     21: }

     23: PetscErrorCode NEPDeflationExtendInvariantPair(NEP_EXT_OP extop,Vec u,PetscScalar lambda,PetscInt k)
     24: {
     25:   Vec            uu;
     26:   PetscInt       ld,i;
     27:   PetscMPIInt    np;
     28:   PetscReal      norm;

     30:   PetscFunctionBegin;
     31:   PetscCall(BVGetColumn(extop->X,k,&uu));
     32:   ld = extop->szd+1;
     33:   PetscCall(NEPDeflationCopyToExtendedVec(extop,uu,extop->H+k*ld,u,PETSC_TRUE));
     34:   PetscCall(BVRestoreColumn(extop->X,k,&uu));
     35:   PetscCall(BVNormColumn(extop->X,k,NORM_2,&norm));
     36:   PetscCall(BVScaleColumn(extop->X,k,1.0/norm));
     37:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)u),&np));
     38:   for (i=0;i<k;i++) extop->H[k*ld+i] *= PetscSqrtReal(np)/norm;
     39:   extop->H[k*(ld+1)] = lambda;
     40:   PetscFunctionReturn(PETSC_SUCCESS);
     41: }

     43: PetscErrorCode NEPDeflationExtractEigenpair(NEP_EXT_OP extop,PetscInt k,Vec u,PetscScalar lambda,DS ds)
     44: {
     45:   Mat            A,H;
     46:   PetscInt       ldh=extop->szd+1,ldds,k1=k+1;
     47:   PetscScalar    *eigr,*eigi,*t,*Z;
     48:   Vec            x;

     50:   PetscFunctionBegin;
     51:   PetscCall(NEPDeflationExtendInvariantPair(extop,u,lambda,k));
     52:   PetscCall(MatCreateSeqDense(PETSC_COMM_SELF,k1,k1,extop->H,&H));
     53:   PetscCall(MatDenseSetLDA(H,ldh));
     54:   PetscCall(PetscCalloc3(k1,&eigr,k1,&eigi,extop->szd,&t));
     55:   PetscCall(DSReset(ds));
     56:   PetscCall(DSSetType(ds,DSNHEP));
     57:   PetscCall(DSAllocate(ds,ldh));
     58:   PetscCall(DSGetLeadingDimension(ds,&ldds));
     59:   PetscCall(DSSetDimensions(ds,k1,0,k1));
     60:   PetscCall(DSGetMat(ds,DS_MAT_A,&A));
     61:   PetscCall(MatCopy(H,A,SAME_NONZERO_PATTERN));
     62:   PetscCall(DSRestoreMat(ds,DS_MAT_A,&A));
     63:   PetscCall(MatDestroy(&H));
     64:   PetscCall(DSSolve(ds,eigr,eigi));
     65:   PetscCall(DSVectors(ds,DS_MAT_X,&k,NULL));
     66:   PetscCall(DSGetArray(ds,DS_MAT_X,&Z));
     67:   PetscCall(BVMultColumn(extop->X,1.0,Z[k*ldds+k],k,Z+k*ldds));
     68:   PetscCall(DSRestoreArray(ds,DS_MAT_X,&Z));
     69:   PetscCall(BVGetColumn(extop->X,k,&x));
     70:   PetscCall(NEPDeflationCopyToExtendedVec(extop,x,t,u,PETSC_FALSE));
     71:   PetscCall(BVRestoreColumn(extop->X,k,&x));
     72:   PetscCall(PetscFree3(eigr,eigi,t));
     73:   PetscFunctionReturn(PETSC_SUCCESS);
     74: }

     76: PetscErrorCode NEPDeflationCopyToExtendedVec(NEP_EXT_OP extop,Vec v,PetscScalar *a,Vec vex,PetscBool back)
     77: {
     78:   PetscMPIInt    np,rk,count;
     79:   PetscScalar    *array1,*array2;
     80:   PetscInt       nloc;

     82:   PetscFunctionBegin;
     83:   if (extop->szd) {
     84:     PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)vex),&rk));
     85:     PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)vex),&np));
     86:     PetscCall(BVGetSizes(extop->nep->V,&nloc,NULL,NULL));
     87:     if (v) {
     88:       PetscCall(VecGetArray(v,&array1));
     89:       PetscCall(VecGetArray(vex,&array2));
     90:       if (back) PetscCall(PetscArraycpy(array1,array2,nloc));
     91:       else PetscCall(PetscArraycpy(array2,array1,nloc));
     92:       PetscCall(VecRestoreArray(v,&array1));
     93:       PetscCall(VecRestoreArray(vex,&array2));
     94:     }
     95:     if (a) {
     96:       PetscCall(VecGetArray(vex,&array2));
     97:       if (back) {
     98:         PetscCall(PetscArraycpy(a,array2+nloc,extop->szd));
     99:         PetscCall(PetscMPIIntCast(extop->szd,&count));
    100:         PetscCallMPI(MPI_Bcast(a,count,MPIU_SCALAR,np-1,PetscObjectComm((PetscObject)vex)));
    101:       } else {
    102:         PetscCall(PetscArraycpy(array2+nloc,a,extop->szd));
    103:         PetscCall(PetscMPIIntCast(extop->szd,&count));
    104:         PetscCallMPI(MPI_Bcast(array2+nloc,count,MPIU_SCALAR,np-1,PetscObjectComm((PetscObject)vex)));
    105:       }
    106:       PetscCall(VecRestoreArray(vex,&array2));
    107:     }
    108:   } else {
    109:     if (back) PetscCall(VecCopy(vex,v));
    110:     else PetscCall(VecCopy(v,vex));
    111:   }
    112:   PetscFunctionReturn(PETSC_SUCCESS);
    113: }

    115: PetscErrorCode NEPDeflationCreateVec(NEP_EXT_OP extop,Vec *v)
    116: {
    117:   PetscInt       nloc;
    118:   Vec            u;
    119:   VecType        type;

    121:   PetscFunctionBegin;
    122:   if (extop->szd) {
    123:     PetscCall(BVGetColumn(extop->nep->V,0,&u));
    124:     PetscCall(VecGetType(u,&type));
    125:     PetscCall(BVRestoreColumn(extop->nep->V,0,&u));
    126:     PetscCall(VecCreate(PetscObjectComm((PetscObject)extop->nep),v));
    127:     PetscCall(VecSetType(*v,type));
    128:     PetscCall(BVGetSizes(extop->nep->V,&nloc,NULL,NULL));
    129:     nloc += extop->szd;
    130:     PetscCall(VecSetSizes(*v,nloc,PETSC_DECIDE));
    131:   } else PetscCall(BVCreateVec(extop->nep->V,v));
    132:   PetscFunctionReturn(PETSC_SUCCESS);
    133: }

    135: PetscErrorCode NEPDeflationCreateBV(NEP_EXT_OP extop,PetscInt sz,BV *V)
    136: {
    137:   PetscInt           nloc;
    138:   BVType             type;
    139:   BVOrthogType       otype;
    140:   BVOrthogRefineType oref;
    141:   PetscReal          oeta;
    142:   BVOrthogBlockType  oblock;
    143:   NEP                nep=extop->nep;

    145:   PetscFunctionBegin;
    146:   if (extop->szd) {
    147:     PetscCall(BVGetSizes(nep->V,&nloc,NULL,NULL));
    148:     PetscCall(BVCreate(PetscObjectComm((PetscObject)nep),V));
    149:     PetscCall(BVSetSizes(*V,nloc+extop->szd,PETSC_DECIDE,sz));
    150:     PetscCall(BVGetType(nep->V,&type));
    151:     PetscCall(BVSetType(*V,type));
    152:     PetscCall(BVGetOrthogonalization(nep->V,&otype,&oref,&oeta,&oblock));
    153:     PetscCall(BVSetOrthogonalization(*V,otype,oref,oeta,oblock));
    154:     PetscCall(PetscObjectStateIncrease((PetscObject)*V));
    155:   } else PetscCall(BVDuplicateResize(nep->V,sz,V));
    156:   PetscFunctionReturn(PETSC_SUCCESS);
    157: }

    159: PetscErrorCode NEPDeflationSetRandomVec(NEP_EXT_OP extop,Vec v)
    160: {
    161:   PetscInt       n,next,i;
    162:   PetscRandom    rand;
    163:   PetscScalar    *array;
    164:   PetscMPIInt    nn,np;

    166:   PetscFunctionBegin;
    167:   PetscCall(BVGetRandomContext(extop->nep->V,&rand));
    168:   PetscCall(VecSetRandom(v,rand));
    169:   if (extop->szd) {
    170:     PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)v),&np));
    171:     PetscCall(BVGetSizes(extop->nep->V,&n,NULL,NULL));
    172:     PetscCall(VecGetLocalSize(v,&next));
    173:     PetscCall(VecGetArray(v,&array));
    174:     for (i=n+extop->n;i<next;i++) array[i] = 0.0;
    175:     for (i=n;i<n+extop->n;i++) array[i] /= PetscSqrtReal(np);
    176:     PetscCall(PetscMPIIntCast(extop->n,&nn));
    177:     PetscCallMPI(MPI_Bcast(array+n,nn,MPIU_SCALAR,0,PetscObjectComm((PetscObject)v)));
    178:     PetscCall(VecRestoreArray(v,&array));
    179:   }
    180:   PetscFunctionReturn(PETSC_SUCCESS);
    181: }

    183: static PetscErrorCode NEPDeflationEvaluateBasisMat(NEP_EXT_OP extop,PetscInt idx,PetscBool hat,PetscScalar *bval,PetscScalar *Hj,PetscScalar *Hjprev)
    184: {
    185:   PetscInt       i,k,n=extop->n,ldhj=extop->szd,ldh=extop->szd+1;
    186:   PetscScalar    sone=1.0,zero=0.0;
    187:   PetscBLASInt   ldh_,ldhj_,n_;

    189:   PetscFunctionBegin;
    190:   i = (idx<0)?extop->szd*extop->szd*(-idx):extop->szd*extop->szd;
    191:   PetscCall(PetscArrayzero(Hj,i));
    192:   PetscCall(PetscBLASIntCast(ldhj+1,&ldh_));
    193:   PetscCall(PetscBLASIntCast(ldhj,&ldhj_));
    194:   PetscCall(PetscBLASIntCast(n,&n_));
    195:   if (idx<1) {
    196:     if (!hat) for (i=0;i<extop->n;i++) Hj[i+i*ldhj] = 1.0;
    197:     else for (i=0;i<extop->n;i++) Hj[i+i*ldhj] = 0.0;
    198:   } else {
    199:       for (i=0;i<n;i++) extop->H[i*ldh+i] -= extop->bc[idx-1];
    200:       PetscCallBLAS("BLASgemm",BLASgemm_("N","N",&n_,&n_,&n_,&sone,extop->H,&ldh_,Hjprev,&ldhj_,&zero,Hj,&ldhj_));
    201:       for (i=0;i<n;i++) extop->H[i*ldh+i] += extop->bc[idx-1];
    202:       if (hat) for (i=0;i<n;i++) Hj[i*(ldhj+1)] += bval[idx-1];
    203:   }
    204:   if (idx<0) {
    205:     idx = -idx;
    206:     for (k=1;k<idx;k++) {
    207:       for (i=0;i<n;i++) extop->H[i*ldh+i] -= extop->bc[k-1];
    208:       PetscCallBLAS("BLASgemm",BLASgemm_("N","N",&n_,&n_,&n_,&sone,extop->H,&ldh_,Hj+(k-1)*ldhj*ldhj,&ldhj_,&zero,Hj+k*ldhj*ldhj,&ldhj_));
    209:       for (i=0;i<n;i++) extop->H[i*ldh+i] += extop->bc[k-1];
    210:       if (hat) for (i=0;i<n;i++) Hj[i*(ldhj+1)] += bval[k-1];
    211:     }
    212:   }
    213:   PetscFunctionReturn(PETSC_SUCCESS);
    214: }

    216: PetscErrorCode NEPDeflationLocking(NEP_EXT_OP extop,Vec u,PetscScalar lambda)
    217: {
    218:   PetscInt       i;

    220:   PetscFunctionBegin;
    221:   PetscCall(NEPDeflationExtendInvariantPair(extop,u,lambda,extop->n));
    222:   extop->n++;
    223:   PetscCall(BVSetActiveColumns(extop->X,0,extop->n));
    224:   if (extop->n <= extop->szd) {
    225:     /* update XpX */
    226:     PetscCall(BVDotColumn(extop->X,extop->n-1,extop->XpX+(extop->n-1)*extop->szd));
    227:     extop->XpX[(extop->n-1)*(1+extop->szd)] = 1.0;
    228:     for (i=0;i<extop->n-1;i++) extop->XpX[i*extop->szd+extop->n-1] = PetscConj(extop->XpX[(extop->n-1)*extop->szd+i]);
    229:     /* determine minimality index */
    230:     extop->midx = PetscMin(extop->max_midx,extop->n);
    231:     /* polynominal basis coefficients */
    232:     for (i=0;i<extop->midx;i++) extop->bc[i] = extop->nep->target;
    233:     /* evaluate the polynomial basis in H */
    234:     PetscCall(NEPDeflationEvaluateBasisMat(extop,-extop->midx,PETSC_FALSE,NULL,extop->Hj,NULL));
    235:   }
    236:   PetscFunctionReturn(PETSC_SUCCESS);
    237: }

    239: static PetscErrorCode NEPDeflationEvaluateHatFunction(NEP_EXT_OP extop, PetscInt idx,PetscScalar lambda,PetscScalar *y,PetscScalar *hfj,PetscScalar *hfjp,PetscInt ld)
    240: {
    241:   PetscInt          i,j,k,off,ini,fin,sz,ldh,n=extop->n;
    242:   Mat               A,B;
    243:   PetscScalar       *array;
    244:   const PetscScalar *barray;

    246:   PetscFunctionBegin;
    247:   if (idx<0) {ini = 0; fin = extop->nep->nt;}
    248:   else {ini = idx; fin = idx+1;}
    249:   if (y) sz = hfjp?n+2:n+1;
    250:   else sz = hfjp?3*n:2*n;
    251:   ldh = extop->szd+1;
    252:   PetscCall(MatCreateSeqDense(PETSC_COMM_SELF,sz,sz,NULL,&A));
    253:   PetscCall(MatCreateSeqDense(PETSC_COMM_SELF,sz,sz,NULL,&B));
    254:   PetscCall(MatDenseGetArray(A,&array));
    255:   for (j=0;j<n;j++)
    256:     for (i=0;i<n;i++) array[j*sz+i] = extop->H[j*ldh+i];
    257:   PetscCall(MatDenseRestoreArrayWrite(A,&array));
    258:   if (y) {
    259:     PetscCall(MatDenseGetArray(A,&array));
    260:     array[extop->n*(sz+1)] = lambda;
    261:     if (hfjp) { array[(n+1)*sz+n] = 1.0; array[(n+1)*sz+n+1] = lambda;}
    262:     for (i=0;i<n;i++) array[n*sz+i] = y[i];
    263:     PetscCall(MatDenseRestoreArrayWrite(A,&array));
    264:     for (j=ini;j<fin;j++) {
    265:       PetscCall(FNEvaluateFunctionMat(extop->nep->f[j],A,B));
    266:       PetscCall(MatDenseGetArrayRead(B,&barray));
    267:       for (i=0;i<n;i++) hfj[j*ld+i] = barray[n*sz+i];
    268:       if (hfjp) for (i=0;i<n;i++) hfjp[j*ld+i] = barray[(n+1)*sz+i];
    269:       PetscCall(MatDenseRestoreArrayRead(B,&barray));
    270:     }
    271:   } else {
    272:     off = idx<0?ld*n:0;
    273:     PetscCall(MatDenseGetArray(A,&array));
    274:     for (k=0;k<n;k++) {
    275:       array[(n+k)*sz+k] = 1.0;
    276:       array[(n+k)*sz+n+k] = lambda;
    277:     }
    278:     if (hfjp) for (k=0;k<n;k++) {
    279:       array[(2*n+k)*sz+n+k] = 1.0;
    280:       array[(2*n+k)*sz+2*n+k] = lambda;
    281:     }
    282:     PetscCall(MatDenseRestoreArray(A,&array));
    283:     for (j=ini;j<fin;j++) {
    284:       PetscCall(FNEvaluateFunctionMat(extop->nep->f[j],A,B));
    285:       PetscCall(MatDenseGetArrayRead(B,&barray));
    286:       for (i=0;i<n;i++) for (k=0;k<n;k++) hfj[j*off+i*ld+k] = barray[n*sz+i*sz+k];
    287:       if (hfjp) for (k=0;k<n;k++) for (i=0;i<n;i++) hfjp[j*off+i*ld+k] = barray[2*n*sz+i*sz+k];
    288:       PetscCall(MatDenseRestoreArrayRead(B,&barray));
    289:     }
    290:   }
    291:   PetscCall(MatDestroy(&A));
    292:   PetscCall(MatDestroy(&B));
    293:   PetscFunctionReturn(PETSC_SUCCESS);
    294: }

    296: static PetscErrorCode MatMult_NEPDeflation(Mat M,Vec x,Vec y)
    297: {
    298:   NEP_DEF_MATSHELL  *matctx;
    299:   NEP_EXT_OP        extop;
    300:   Vec               x1,y1;
    301:   PetscScalar       *yy,sone=1.0,zero=0.0;
    302:   const PetscScalar *xx;
    303:   PetscInt          nloc,i;
    304:   PetscMPIInt       np;
    305:   PetscBLASInt      n_,one=1,szd_;

    307:   PetscFunctionBegin;
    308:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)M),&np));
    309:   PetscCall(MatShellGetContext(M,&matctx));
    310:   extop = matctx->extop;
    311:   if (extop->ref) PetscCall(VecZeroEntries(y));
    312:   if (extop->szd) {
    313:     x1 = matctx->w[0]; y1 = matctx->w[1];
    314:     PetscCall(VecGetArrayRead(x,&xx));
    315:     PetscCall(VecPlaceArray(x1,xx));
    316:     PetscCall(VecGetArray(y,&yy));
    317:     PetscCall(VecPlaceArray(y1,yy));
    318:     PetscCall(MatMult(matctx->T,x1,y1));
    319:     if (!extop->ref && extop->n) {
    320:       PetscCall(VecGetLocalSize(x1,&nloc));
    321:       /* copy for avoiding warning of constant array xx */
    322:       for (i=0;i<extop->n;i++) matctx->work[i] = xx[nloc+i]*PetscSqrtReal(np);
    323:       PetscCall(BVMultVec(matctx->U,1.0,1.0,y1,matctx->work));
    324:       PetscCall(BVDotVec(extop->X,x1,matctx->work));
    325:       PetscCall(PetscBLASIntCast(extop->n,&n_));
    326:       PetscCall(PetscBLASIntCast(extop->szd,&szd_));
    327:       PetscCallBLAS("BLASgemv",BLASgemv_("N",&n_,&n_,&sone,matctx->A,&szd_,matctx->work,&one,&zero,yy+nloc,&one));
    328:       PetscCallBLAS("BLASgemv",BLASgemv_("N",&n_,&n_,&sone,matctx->B,&szd_,xx+nloc,&one,&sone,yy+nloc,&one));
    329:       for (i=0;i<extop->n;i++) yy[nloc+i] /= PetscSqrtReal(np);
    330:     }
    331:     PetscCall(VecResetArray(x1));
    332:     PetscCall(VecRestoreArrayRead(x,&xx));
    333:     PetscCall(VecResetArray(y1));
    334:     PetscCall(VecRestoreArray(y,&yy));
    335:   } else PetscCall(MatMult(matctx->T,x,y));
    336:   PetscFunctionReturn(PETSC_SUCCESS);
    337: }

    339: static PetscErrorCode MatCreateVecs_NEPDeflation(Mat M,Vec *right,Vec *left)
    340: {
    341:   NEP_DEF_MATSHELL *matctx;

    343:   PetscFunctionBegin;
    344:   PetscCall(MatShellGetContext(M,&matctx));
    345:   if (right) PetscCall(VecDuplicate(matctx->w[0],right));
    346:   if (left) PetscCall(VecDuplicate(matctx->w[0],left));
    347:   PetscFunctionReturn(PETSC_SUCCESS);
    348: }

    350: static PetscErrorCode MatDestroy_NEPDeflation(Mat M)
    351: {
    352:   NEP_DEF_MATSHELL *matctx;

    354:   PetscFunctionBegin;
    355:   PetscCall(MatShellGetContext(M,&matctx));
    356:   if (matctx->extop->szd) {
    357:     PetscCall(BVDestroy(&matctx->U));
    358:     PetscCall(PetscFree2(matctx->hfj,matctx->work));
    359:     PetscCall(PetscFree2(matctx->A,matctx->B));
    360:     PetscCall(VecDestroy(&matctx->w[0]));
    361:     PetscCall(VecDestroy(&matctx->w[1]));
    362:   }
    363:   if (matctx->P != matctx->T) PetscCall(MatDestroy(&matctx->P));
    364:   PetscCall(MatDestroy(&matctx->T));
    365:   PetscCall(PetscFree(matctx));
    366:   PetscFunctionReturn(PETSC_SUCCESS);
    367: }

    369: static PetscErrorCode NEPDeflationEvaluateBasis(NEP_EXT_OP extop,PetscScalar lambda,PetscInt n,PetscScalar *val,PetscBool jacobian)
    370: {
    371:   PetscScalar p;
    372:   PetscInt    i;

    374:   PetscFunctionBegin;
    375:   if (!jacobian) {
    376:     val[0] = 1.0;
    377:     for (i=1;i<extop->n;i++) val[i] = val[i-1]*(lambda-extop->bc[i-1]);
    378:   } else {
    379:     val[0] = 0.0;
    380:     p = 1.0;
    381:     for (i=1;i<extop->n;i++) {
    382:       val[i] = val[i-1]*(lambda-extop->bc[i-1])+p;
    383:       p *= (lambda-extop->bc[i-1]);
    384:     }
    385:   }
    386:   PetscFunctionReturn(PETSC_SUCCESS);
    387: }

    389: static PetscErrorCode NEPDeflationComputeShellMat(NEP_EXT_OP extop,PetscScalar lambda,PetscBool jacobian,Mat *M)
    390: {
    391:   NEP_DEF_MATSHELL *matctx,*matctxC;
    392:   PetscInt         nloc,mloc,n=extop->n,j,i,szd=extop->szd,ldh=szd+1,k;
    393:   Mat              F,Mshell,Mcomp;
    394:   PetscBool        ini=PETSC_FALSE;
    395:   PetscScalar      *hf,*hfj,*hfjp,sone=1.0,*hH,*hHprev,*pts,*B,*A,*Hj=extop->Hj,*basisv,zero=0.0;
    396:   PetscBLASInt     n_,info,szd_;

    398:   PetscFunctionBegin;
    399:   if (!M) Mshell = jacobian?extop->MJ:extop->MF;
    400:   else Mshell = *M;
    401:   Mcomp = jacobian?extop->MF:extop->MJ;
    402:   if (!Mshell) {
    403:     ini = PETSC_TRUE;
    404:     PetscCall(PetscNew(&matctx));
    405:     PetscCall(MatGetLocalSize(extop->nep->function,&mloc,&nloc));
    406:     nloc += szd; mloc += szd;
    407:     PetscCall(MatCreateShell(PetscObjectComm((PetscObject)extop->nep),nloc,mloc,PETSC_DETERMINE,PETSC_DETERMINE,matctx,&Mshell));
    408:     PetscCall(MatShellSetOperation(Mshell,MATOP_MULT,(void(*)(void))MatMult_NEPDeflation));
    409:     PetscCall(MatShellSetOperation(Mshell,MATOP_CREATE_VECS,(void(*)(void))MatCreateVecs_NEPDeflation));
    410:     PetscCall(MatShellSetOperation(Mshell,MATOP_DESTROY,(void(*)(void))MatDestroy_NEPDeflation));
    411:     matctx->nep = extop->nep;
    412:     matctx->extop = extop;
    413:     if (!M) {
    414:       if (jacobian) { matctx->jacob = PETSC_TRUE; matctx->T = extop->nep->jacobian; extop->MJ = Mshell; }
    415:       else { matctx->jacob = PETSC_FALSE; matctx->T = extop->nep->function; extop->MF = Mshell; }
    416:       PetscCall(PetscObjectReference((PetscObject)matctx->T));
    417:       if (!jacobian) {
    418:         if (extop->nep->function_pre && extop->nep->function_pre != extop->nep->function) {
    419:           matctx->P = extop->nep->function_pre;
    420:           PetscCall(PetscObjectReference((PetscObject)matctx->P));
    421:         } else matctx->P = matctx->T;
    422:       }
    423:     } else {
    424:       matctx->jacob = jacobian;
    425:       PetscCall(MatDuplicate(jacobian?extop->nep->jacobian:extop->nep->function,MAT_DO_NOT_COPY_VALUES,&matctx->T));
    426:       *M = Mshell;
    427:       if (!jacobian) {
    428:         if (extop->nep->function_pre && extop->nep->function_pre != extop->nep->function) PetscCall(MatDuplicate(extop->nep->function_pre,MAT_DO_NOT_COPY_VALUES,&matctx->P));
    429:         else matctx->P = matctx->T;
    430:       }
    431:     }
    432:     if (szd) {
    433:       PetscCall(BVCreateVec(extop->nep->V,matctx->w));
    434:       PetscCall(VecDuplicate(matctx->w[0],matctx->w+1));
    435:       PetscCall(BVDuplicateResize(extop->nep->V,szd,&matctx->U));
    436:       PetscCall(PetscMalloc2(extop->simpU?2*(szd)*(szd):2*(szd)*(szd)*extop->nep->nt,&matctx->hfj,szd,&matctx->work));
    437:       PetscCall(PetscMalloc2(szd*szd,&matctx->A,szd*szd,&matctx->B));
    438:     }
    439:   } else PetscCall(MatShellGetContext(Mshell,&matctx));
    440:   if (ini || matctx->theta != lambda || matctx->n != extop->n) {
    441:     if (ini || matctx->theta != lambda) {
    442:       if (jacobian) PetscCall(NEPComputeJacobian(extop->nep,lambda,matctx->T));
    443:       else PetscCall(NEPComputeFunction(extop->nep,lambda,matctx->T,matctx->P));
    444:     }
    445:     if (n) {
    446:       matctx->hfjset = PETSC_FALSE;
    447:       if (!extop->simpU) {
    448:         /* likely hfjp has been already computed */
    449:         if (Mcomp) {
    450:           PetscCall(MatShellGetContext(Mcomp,&matctxC));
    451:           if (matctxC->hfjset && matctxC->theta == lambda && matctxC->n == extop->n) {
    452:             PetscCall(PetscArraycpy(matctx->hfj,matctxC->hfj,2*extop->szd*extop->szd*extop->nep->nt));
    453:             matctx->hfjset = PETSC_TRUE;
    454:           }
    455:         }
    456:         hfj = matctx->hfj; hfjp = matctx->hfj+extop->szd*extop->szd*extop->nep->nt;
    457:         if (!matctx->hfjset) {
    458:           PetscCall(NEPDeflationEvaluateHatFunction(extop,-1,lambda,NULL,hfj,hfjp,n));
    459:           matctx->hfjset = PETSC_TRUE;
    460:         }
    461:         PetscCall(BVSetActiveColumns(matctx->U,0,n));
    462:         hf = jacobian?hfjp:hfj;
    463:         PetscCall(MatCreateSeqDense(PETSC_COMM_SELF,n,n,hf,&F));
    464:         PetscCall(BVMatMult(extop->X,extop->nep->A[0],matctx->U));
    465:         PetscCall(BVMultInPlace(matctx->U,F,0,n));
    466:         PetscCall(BVSetActiveColumns(extop->W,0,extop->n));
    467:         for (j=1;j<extop->nep->nt;j++) {
    468:           PetscCall(BVMatMult(extop->X,extop->nep->A[j],extop->W));
    469:           PetscCall(MatDensePlaceArray(F,hf+j*n*n));
    470:           PetscCall(BVMult(matctx->U,1.0,1.0,extop->W,F));
    471:           PetscCall(MatDenseResetArray(F));
    472:         }
    473:         PetscCall(MatDestroy(&F));
    474:       } else {
    475:         hfj = matctx->hfj;
    476:         PetscCall(BVSetActiveColumns(matctx->U,0,n));
    477:         PetscCall(BVMatMult(extop->X,matctx->T,matctx->U));
    478:         for (j=0;j<n;j++) {
    479:           for (i=0;i<n;i++) hfj[j*n+i] = -extop->H[j*ldh+i];
    480:           hfj[j*(n+1)] += lambda;
    481:         }
    482:         PetscCall(PetscBLASIntCast(n,&n_));
    483:         PetscCall(PetscFPTrapPush(PETSC_FP_TRAP_OFF));
    484:         PetscCallBLAS("LAPACKtrtri",LAPACKtrtri_("U","N",&n_,hfj,&n_,&info));
    485:         PetscCall(PetscFPTrapPop());
    486:         SlepcCheckLapackInfo("trtri",info);
    487:         PetscCall(MatCreateSeqDense(PETSC_COMM_SELF,n,n,hfj,&F));
    488:         PetscCall(BVMultInPlace(matctx->U,F,0,n));
    489:         if (jacobian) {
    490:           PetscCall(NEPDeflationComputeFunction(extop,lambda,NULL));
    491:           PetscCall(MatShellGetContext(extop->MF,&matctxC));
    492:           PetscCall(BVMult(matctx->U,-1.0,1.0,matctxC->U,F));
    493:         }
    494:         PetscCall(MatDestroy(&F));
    495:       }
    496:       PetscCall(PetscCalloc3(n,&basisv,szd*szd,&hH,szd*szd,&hHprev));
    497:       PetscCall(NEPDeflationEvaluateBasis(extop,lambda,n,basisv,jacobian));
    498:       A = matctx->A;
    499:       PetscCall(PetscArrayzero(A,szd*szd));
    500:       if (!jacobian) for (i=0;i<n;i++) A[i*(szd+1)] = 1.0;
    501:       for (j=0;j<n;j++)
    502:         for (i=0;i<n;i++)
    503:           for (k=1;k<extop->midx;k++) A[j*szd+i] += basisv[k]*PetscConj(Hj[k*szd*szd+i*szd+j]);
    504:       PetscCall(PetscBLASIntCast(n,&n_));
    505:       PetscCall(PetscBLASIntCast(szd,&szd_));
    506:       B = matctx->B;
    507:       PetscCall(PetscArrayzero(B,szd*szd));
    508:       for (i=1;i<extop->midx;i++) {
    509:         PetscCall(NEPDeflationEvaluateBasisMat(extop,i,PETSC_TRUE,basisv,hH,hHprev));
    510:         PetscCallBLAS("BLASgemm",BLASgemm_("N","N",&n_,&n_,&n_,&sone,extop->XpX,&szd_,hH,&szd_,&zero,hHprev,&szd_));
    511:         PetscCallBLAS("BLASgemm",BLASgemm_("C","N",&n_,&n_,&n_,&sone,extop->Hj+szd*szd*i,&szd_,hHprev,&szd_,&sone,B,&szd_));
    512:         pts = hHprev; hHprev = hH; hH = pts;
    513:       }
    514:       PetscCall(PetscFree3(basisv,hH,hHprev));
    515:     }
    516:     matctx->theta = lambda;
    517:     matctx->n = extop->n;
    518:   }
    519:   PetscFunctionReturn(PETSC_SUCCESS);
    520: }

    522: PetscErrorCode NEPDeflationComputeFunction(NEP_EXT_OP extop,PetscScalar lambda,Mat *F)
    523: {
    524:   PetscFunctionBegin;
    525:   PetscCall(NEPDeflationComputeShellMat(extop,lambda,PETSC_FALSE,NULL));
    526:   if (F) *F = extop->MF;
    527:   PetscFunctionReturn(PETSC_SUCCESS);
    528: }

    530: PetscErrorCode NEPDeflationComputeJacobian(NEP_EXT_OP extop,PetscScalar lambda,Mat *J)
    531: {
    532:   PetscFunctionBegin;
    533:   PetscCall(NEPDeflationComputeShellMat(extop,lambda,PETSC_TRUE,NULL));
    534:   if (J) *J = extop->MJ;
    535:   PetscFunctionReturn(PETSC_SUCCESS);
    536: }

    538: PetscErrorCode NEPDeflationSolveSetUp(NEP_EXT_OP extop,PetscScalar lambda)
    539: {
    540:   NEP_DEF_MATSHELL  *matctx;
    541:   NEP_DEF_FUN_SOLVE solve;
    542:   PetscInt          i,j,n=extop->n;
    543:   Vec               u,tu;
    544:   Mat               F;
    545:   PetscScalar       snone=-1.0,sone=1.0;
    546:   PetscBLASInt      n_,szd_,ldh_,*p,info;
    547:   Mat               Mshell;

    549:   PetscFunctionBegin;
    550:   solve = extop->solve;
    551:   if (lambda!=solve->theta || n!=solve->n) {
    552:     PetscCall(NEPDeflationComputeShellMat(extop,lambda,PETSC_FALSE,solve->sincf?NULL:&solve->T));
    553:     Mshell = (solve->sincf)?extop->MF:solve->T;
    554:     PetscCall(MatShellGetContext(Mshell,&matctx));
    555:     PetscCall(NEP_KSPSetOperators(solve->ksp,matctx->T,matctx->P));
    556:     if (!extop->ref && n) {
    557:       PetscCall(PetscBLASIntCast(n,&n_));
    558:       PetscCall(PetscBLASIntCast(extop->szd,&szd_));
    559:       PetscCall(PetscBLASIntCast(extop->szd+1,&ldh_));
    560:       if (!extop->simpU) {
    561:         PetscCall(BVSetActiveColumns(solve->T_1U,0,n));
    562:         for (i=0;i<n;i++) {
    563:           PetscCall(BVGetColumn(matctx->U,i,&u));
    564:           PetscCall(BVGetColumn(solve->T_1U,i,&tu));
    565:           PetscCall(KSPSolve(solve->ksp,u,tu));
    566:           PetscCall(BVRestoreColumn(solve->T_1U,i,&tu));
    567:           PetscCall(BVRestoreColumn(matctx->U,i,&u));
    568:         }
    569:         PetscCall(MatCreateSeqDense(PETSC_COMM_SELF,n,n,solve->work,&F));
    570:         PetscCall(BVDot(solve->T_1U,extop->X,F));
    571:         PetscCall(MatDestroy(&F));
    572:       } else {
    573:         for (j=0;j<n;j++)
    574:           for (i=0;i<n;i++) solve->work[j*n+i] = extop->XpX[j*extop->szd+i];
    575:         for (i=0;i<n;i++) extop->H[i*ldh_+i] -= lambda;
    576:         PetscCallBLAS("BLAStrsm",BLAStrsm_("R","U","N","N",&n_,&n_,&snone,extop->H,&ldh_,solve->work,&n_));
    577:         for (i=0;i<n;i++) extop->H[i*ldh_+i] += lambda;
    578:       }
    579:       PetscCall(PetscArraycpy(solve->M,matctx->B,extop->szd*extop->szd));
    580:       PetscCallBLAS("BLASgemm",BLASgemm_("N","N",&n_,&n_,&n_,&snone,matctx->A,&szd_,solve->work,&n_,&sone,solve->M,&szd_));
    581:       PetscCall(PetscMalloc1(n,&p));
    582:       PetscCall(PetscFPTrapPush(PETSC_FP_TRAP_OFF));
    583:       PetscCallBLAS("LAPACKgetrf",LAPACKgetrf_(&n_,&n_,solve->M,&szd_,p,&info));
    584:       SlepcCheckLapackInfo("getrf",info);
    585:       PetscCallBLAS("LAPACKgetri",LAPACKgetri_(&n_,solve->M,&szd_,p,solve->work,&n_,&info));
    586:       SlepcCheckLapackInfo("getri",info);
    587:       PetscCall(PetscFPTrapPop());
    588:       PetscCall(PetscFree(p));
    589:     }
    590:     solve->theta = lambda;
    591:     solve->n = n;
    592:   }
    593:   PetscFunctionReturn(PETSC_SUCCESS);
    594: }

    596: PetscErrorCode NEPDeflationFunctionSolve(NEP_EXT_OP extop,Vec b,Vec x)
    597: {
    598:   Vec               b1,x1;
    599:   PetscScalar       *xx,*bb,*x2,*b2,*w,*w2,snone=-1.0,sone=1.0,zero=0.0;
    600:   NEP_DEF_MATSHELL  *matctx;
    601:   NEP_DEF_FUN_SOLVE solve=extop->solve;
    602:   PetscBLASInt      one=1,szd_,n_,ldh_;
    603:   PetscInt          nloc,i;
    604:   PetscMPIInt       np,count;

    606:   PetscFunctionBegin;
    607:   if (extop->ref) PetscCall(VecZeroEntries(x));
    608:   if (extop->szd) {
    609:     x1 = solve->w[0]; b1 = solve->w[1];
    610:     PetscCall(VecGetArray(x,&xx));
    611:     PetscCall(VecPlaceArray(x1,xx));
    612:     PetscCall(VecGetArray(b,&bb));
    613:     PetscCall(VecPlaceArray(b1,bb));
    614:   } else {
    615:     b1 = b; x1 = x;
    616:   }
    617:   PetscCall(KSPSolve(extop->solve->ksp,b1,x1));
    618:   if (!extop->ref && extop->n && extop->szd) {
    619:     PetscCall(PetscBLASIntCast(extop->szd,&szd_));
    620:     PetscCall(PetscBLASIntCast(extop->n,&n_));
    621:     PetscCall(PetscBLASIntCast(extop->szd+1,&ldh_));
    622:     PetscCall(BVGetSizes(extop->nep->V,&nloc,NULL,NULL));
    623:     PetscCall(PetscMalloc2(extop->n,&b2,extop->n,&x2));
    624:     PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)b),&np));
    625:     for (i=0;i<extop->n;i++) b2[i] = bb[nloc+i]*PetscSqrtReal(np);
    626:     w = solve->work; w2 = solve->work+extop->n;
    627:     PetscCall(MatShellGetContext(solve->sincf?extop->MF:solve->T,&matctx));
    628:     PetscCall(PetscArraycpy(w2,b2,extop->n));
    629:     PetscCall(BVDotVec(extop->X,x1,w));
    630:     PetscCallBLAS("BLASgemv",BLASgemv_("N",&n_,&n_,&snone,matctx->A,&szd_,w,&one,&sone,w2,&one));
    631:     PetscCallBLAS("BLASgemv",BLASgemv_("N",&n_,&n_,&sone,solve->M,&szd_,w2,&one,&zero,x2,&one));
    632:     if (extop->simpU) {
    633:       for (i=0;i<extop->n;i++) extop->H[i+i*(extop->szd+1)] -= solve->theta;
    634:       for (i=0;i<extop->n;i++) w[i] = x2[i];
    635:       PetscCallBLAS("BLAStrsm",BLAStrsm_("L","U","N","N",&n_,&one,&snone,extop->H,&ldh_,w,&n_));
    636:       for (i=0;i<extop->n;i++) extop->H[i+i*(extop->szd+1)] += solve->theta;
    637:       PetscCall(BVMultVec(extop->X,-1.0,1.0,x1,w));
    638:     } else PetscCall(BVMultVec(solve->T_1U,-1.0,1.0,x1,x2));
    639:     for (i=0;i<extop->n;i++) xx[i+nloc] = x2[i]/PetscSqrtReal(np);
    640:     PetscCall(PetscMPIIntCast(extop->n,&count));
    641:     PetscCallMPI(MPI_Bcast(xx+nloc,count,MPIU_SCALAR,np-1,PetscObjectComm((PetscObject)b)));
    642:   }
    643:   if (extop->szd) {
    644:     PetscCall(VecResetArray(x1));
    645:     PetscCall(VecRestoreArray(x,&xx));
    646:     PetscCall(VecResetArray(b1));
    647:     PetscCall(VecRestoreArray(b,&bb));
    648:     if (!extop->ref && extop->n) PetscCall(PetscFree2(b2,x2));
    649:   }
    650:   PetscFunctionReturn(PETSC_SUCCESS);
    651: }

    653: PetscErrorCode NEPDeflationSetRefine(NEP_EXT_OP extop,PetscBool ref)
    654: {
    655:   PetscFunctionBegin;
    656:   extop->ref = ref;
    657:   PetscFunctionReturn(PETSC_SUCCESS);
    658: }

    660: PetscErrorCode NEPDeflationReset(NEP_EXT_OP extop)
    661: {
    662:   PetscInt          j;
    663:   NEP_DEF_FUN_SOLVE solve;

    665:   PetscFunctionBegin;
    666:   if (!extop) PetscFunctionReturn(PETSC_SUCCESS);
    667:   PetscCall(PetscFree(extop->H));
    668:   PetscCall(BVDestroy(&extop->X));
    669:   if (extop->szd) {
    670:     PetscCall(VecDestroy(&extop->w));
    671:     PetscCall(PetscFree3(extop->Hj,extop->XpX,extop->bc));
    672:     PetscCall(BVDestroy(&extop->W));
    673:   }
    674:   PetscCall(MatDestroy(&extop->MF));
    675:   PetscCall(MatDestroy(&extop->MJ));
    676:   if (extop->solve) {
    677:     solve = extop->solve;
    678:     if (extop->szd) {
    679:       if (!extop->simpU) PetscCall(BVDestroy(&solve->T_1U));
    680:       PetscCall(PetscFree2(solve->M,solve->work));
    681:       PetscCall(VecDestroy(&solve->w[0]));
    682:       PetscCall(VecDestroy(&solve->w[1]));
    683:     }
    684:     if (!solve->sincf) PetscCall(MatDestroy(&solve->T));
    685:     PetscCall(PetscFree(extop->solve));
    686:   }
    687:   if (extop->proj) {
    688:     if (extop->szd) {
    689:       for (j=0;j<extop->nep->nt;j++) PetscCall(MatDestroy(&extop->proj->V1pApX[j]));
    690:       PetscCall(MatDestroy(&extop->proj->XpV1));
    691:       PetscCall(PetscFree3(extop->proj->V2,extop->proj->V1pApX,extop->proj->work));
    692:       PetscCall(VecDestroy(&extop->proj->w));
    693:       PetscCall(BVDestroy(&extop->proj->V1));
    694:     }
    695:     PetscCall(PetscFree(extop->proj));
    696:   }
    697:   PetscCall(PetscFree(extop));
    698:   PetscFunctionReturn(PETSC_SUCCESS);
    699: }

    701: PetscErrorCode NEPDeflationInitialize(NEP nep,BV X,KSP ksp,PetscBool sincfun,PetscInt sz,NEP_EXT_OP *extop)
    702: {
    703:   NEP_EXT_OP        op;
    704:   NEP_DEF_FUN_SOLVE solve;
    705:   PetscInt          szd;
    706:   Vec               x;

    708:   PetscFunctionBegin;
    709:   PetscCall(NEPDeflationReset(*extop));
    710:   PetscCall(PetscNew(&op));
    711:   *extop  = op;
    712:   op->nep = nep;
    713:   op->n   = 0;
    714:   op->szd = szd = sz-1;
    715:   op->max_midx = PetscMin(MAX_MINIDX,szd);
    716:   op->X = X;
    717:   if (!X) PetscCall(BVDuplicateResize(nep->V,sz,&op->X));
    718:   else PetscCall(PetscObjectReference((PetscObject)X));
    719:   PetscCall(PetscCalloc1(sz*sz,&(op)->H));
    720:   if (op->szd) {
    721:     PetscCall(BVGetColumn(op->X,0,&x));
    722:     PetscCall(VecDuplicate(x,&op->w));
    723:     PetscCall(BVRestoreColumn(op->X,0,&x));
    724:     op->simpU = PETSC_FALSE;
    725:     if (nep->fui==NEP_USER_INTERFACE_SPLIT) {
    726:       /* undocumented option to use the simple expression for U = T*X*inv(lambda-H) */
    727:       PetscCall(PetscOptionsGetBool(NULL,NULL,"-nep_deflation_simpleu",&op->simpU,NULL));
    728:     } else {
    729:       op->simpU = PETSC_TRUE;
    730:     }
    731:     PetscCall(PetscCalloc3(szd*szd*op->max_midx,&(op)->Hj,szd*szd,&(op)->XpX,szd,&op->bc));
    732:     PetscCall(BVDuplicateResize(op->X,op->szd,&op->W));
    733:   }
    734:   if (ksp) {
    735:     PetscCall(PetscNew(&solve));
    736:     op->solve    = solve;
    737:     solve->ksp   = ksp;
    738:     solve->sincf = sincfun;
    739:     solve->n     = -1;
    740:     if (op->szd) {
    741:       if (!op->simpU) PetscCall(BVDuplicateResize(nep->V,szd,&solve->T_1U));
    742:       PetscCall(PetscMalloc2(szd*szd,&solve->M,2*szd*szd,&solve->work));
    743:       PetscCall(BVCreateVec(nep->V,&solve->w[0]));
    744:       PetscCall(VecDuplicate(solve->w[0],&solve->w[1]));
    745:     }
    746:   }
    747:   PetscFunctionReturn(PETSC_SUCCESS);
    748: }

    750: PetscErrorCode NEPDeflationDSNEPComputeMatrix(DS ds,PetscScalar lambda,PetscBool deriv,DSMatType mat,void *ctx)
    751: {
    752:   Mat               A,Ei;
    753:   PetscScalar       *T,*w1,*w2,*w=NULL,*ww,*hH,*hHprev,*pts;
    754:   PetscScalar       alpha,alpha2,*AB,sone=1.0,zero=0.0,*basisv,s;
    755:   const PetscScalar *E;
    756:   PetscInt          i,ldds,nwork=0,szd,nv,j,k,n;
    757:   PetscBLASInt      inc=1,nv_,ldds_,dim_,szdk,szd_,n_,ldh_;
    758:   PetscMPIInt       np;
    759:   NEP_DEF_PROJECT   proj=(NEP_DEF_PROJECT)ctx;
    760:   NEP_EXT_OP        extop=proj->extop;
    761:   NEP               nep=extop->nep;

    763:   PetscFunctionBegin;
    764:   PetscCall(DSGetDimensions(ds,&nv,NULL,NULL,NULL));
    765:   PetscCall(DSGetLeadingDimension(ds,&ldds));
    766:   PetscCall(DSGetMat(ds,mat,&A));
    767:   PetscCall(MatZeroEntries(A));
    768:   /* mat = V1^*T(lambda)V1 */
    769:   for (i=0;i<nep->nt;i++) {
    770:     if (deriv) PetscCall(FNEvaluateDerivative(nep->f[i],lambda,&alpha));
    771:     else PetscCall(FNEvaluateFunction(nep->f[i],lambda,&alpha));
    772:     PetscCall(DSGetMat(ds,DSMatExtra[i],&Ei));
    773:     PetscCall(MatAXPY(A,alpha,Ei,SAME_NONZERO_PATTERN));
    774:     PetscCall(DSRestoreMat(ds,DSMatExtra[i],&Ei));
    775:   }
    776:   PetscCall(DSRestoreMat(ds,mat,&A));
    777:   if (!extop->ref && extop->n) {
    778:     PetscCall(DSGetArray(ds,mat,&T));
    779:     n = extop->n;
    780:     szd = extop->szd;
    781:     PetscCall(PetscArrayzero(proj->work,proj->lwork));
    782:     PetscCall(PetscBLASIntCast(nv,&nv_));
    783:     PetscCall(PetscBLASIntCast(n,&n_));
    784:     PetscCall(PetscBLASIntCast(ldds,&ldds_));
    785:     PetscCall(PetscBLASIntCast(szd,&szd_));
    786:     PetscCall(PetscBLASIntCast(proj->dim,&dim_));
    787:     PetscCall(PetscBLASIntCast(extop->szd+1,&ldh_));
    788:     w1 = proj->work; w2 = proj->work+proj->dim*proj->dim;
    789:     nwork += 2*proj->dim*proj->dim;

    791:     /* mat = mat + V1^*U(lambda)V2 */
    792:     for (i=0;i<nep->nt;i++) {
    793:       if (extop->simpU) {
    794:         if (deriv) PetscCall(FNEvaluateDerivative(nep->f[i],lambda,&alpha));
    795:         else PetscCall(FNEvaluateFunction(nep->f[i],lambda,&alpha));
    796:         ww = w1; w = w2;
    797:         PetscCall(PetscArraycpy(ww,proj->V2,szd*nv));
    798:         PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)ds),&np));
    799:         for (j=0;j<szd*nv;j++) ww[j] *= PetscSqrtReal(np);
    800:         for (j=0;j<n;j++) extop->H[j*ldh_+j] -= lambda;
    801:         alpha = -alpha;
    802:         PetscCallBLAS("BLAStrsm",BLAStrsm_("L","U","N","N",&n_,&nv_,&alpha,extop->H,&ldh_,ww,&szd_));
    803:         if (deriv) {
    804:           PetscCall(PetscBLASIntCast(szd*nv,&szdk));
    805:           PetscCall(FNEvaluateFunction(nep->f[i],lambda,&alpha2));
    806:           PetscCall(PetscArraycpy(w,proj->V2,szd*nv));
    807:           for (j=0;j<szd*nv;j++) w[j] *= PetscSqrtReal(np);
    808:           alpha2 = -alpha2;
    809:           PetscCallBLAS("BLAStrsm",BLAStrsm_("L","U","N","N",&n_,&nv_,&alpha2,extop->H,&ldh_,w,&szd_));
    810:           alpha2 = 1.0;
    811:           PetscCallBLAS("BLAStrsm",BLAStrsm_("L","U","N","N",&n_,&nv_,&alpha2,extop->H,&ldh_,w,&szd_));
    812:           PetscCallBLAS("BLASaxpy",BLASaxpy_(&szdk,&sone,w,&inc,ww,&inc));
    813:         }
    814:         for (j=0;j<n;j++) extop->H[j*ldh_+j] += lambda;
    815:       } else {
    816:         PetscCall(NEPDeflationEvaluateHatFunction(extop,i,lambda,NULL,w1,w2,szd));
    817:         w = deriv?w2:w1; ww = deriv?w1:w2;
    818:         PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)ds),&np));
    819:         s = PetscSqrtReal(np);
    820:         PetscCallBLAS("BLASgemm",BLASgemm_("N","N",&n_,&nv_,&n_,&s,w,&szd_,proj->V2,&szd_,&zero,ww,&szd_));
    821:       }
    822:       PetscCall(MatDenseGetArrayRead(proj->V1pApX[i],&E));
    823:       PetscCallBLAS("BLASgemm",BLASgemm_("N","N",&nv_,&nv_,&n_,&sone,E,&dim_,ww,&szd_,&sone,T,&ldds_));
    824:       PetscCall(MatDenseRestoreArrayRead(proj->V1pApX[i],&E));
    825:     }

    827:     /* mat = mat + V2^*A(lambda)V1 */
    828:     basisv = proj->work+nwork; nwork += szd;
    829:     hH     = proj->work+nwork; nwork += szd*szd;
    830:     hHprev = proj->work+nwork; nwork += szd*szd;
    831:     AB     = proj->work+nwork;
    832:     PetscCall(NEPDeflationEvaluateBasis(extop,lambda,n,basisv,deriv));
    833:     if (!deriv) for (i=0;i<n;i++) AB[i*(szd+1)] = 1.0;
    834:     for (j=0;j<n;j++)
    835:       for (i=0;i<n;i++)
    836:         for (k=1;k<extop->midx;k++) AB[j*szd+i] += basisv[k]*PetscConj(extop->Hj[k*szd*szd+i*szd+j]);
    837:     PetscCall(MatDenseGetArrayRead(proj->XpV1,&E));
    838:     PetscCallBLAS("BLASgemm",BLASgemm_("N","N",&n_,&nv_,&n_,&sone,AB,&szd_,E,&szd_,&zero,w,&szd_));
    839:     PetscCallBLAS("BLASgemm",BLASgemm_("C","N",&nv_,&nv_,&n_,&sone,proj->V2,&szd_,w,&szd_,&sone,T,&ldds_));
    840:     PetscCall(MatDenseRestoreArrayRead(proj->XpV1,&E));

    842:     /* mat = mat + V2^*B(lambda)V2 */
    843:     PetscCall(PetscArrayzero(AB,szd*szd));
    844:     for (i=1;i<extop->midx;i++) {
    845:       PetscCall(NEPDeflationEvaluateBasisMat(extop,i,PETSC_TRUE,basisv,hH,hHprev));
    846:       PetscCallBLAS("BLASgemm",BLASgemm_("N","N",&n_,&n_,&n_,&sone,extop->XpX,&szd_,hH,&szd_,&zero,hHprev,&szd_));
    847:       PetscCallBLAS("BLASgemm",BLASgemm_("C","N",&n_,&n_,&n_,&sone,extop->Hj+szd*szd*i,&szd_,hHprev,&szd_,&sone,AB,&szd_));
    848:       pts = hHprev; hHprev = hH; hH = pts;
    849:     }
    850:     PetscCallBLAS("BLASgemm",BLASgemm_("N","N",&n_,&nv_,&n_,&sone,AB,&szd_,proj->V2,&szd_,&zero,w,&szd_));
    851:     PetscCallBLAS("BLASgemm",BLASgemm_("C","N",&nv_,&nv_,&n_,&sone,proj->V2,&szd_,w,&szd_,&sone,T,&ldds_));
    852:     PetscCall(DSRestoreArray(ds,mat,&T));
    853:   }
    854:   PetscFunctionReturn(PETSC_SUCCESS);
    855: }

    857: PetscErrorCode NEPDeflationProjectOperator(NEP_EXT_OP extop,BV Vext,DS ds,PetscInt j0,PetscInt j1)
    858: {
    859:   PetscInt        k,j,n=extop->n,dim;
    860:   Vec             v,ve;
    861:   BV              V1;
    862:   Mat             G;
    863:   NEP             nep=extop->nep;
    864:   NEP_DEF_PROJECT proj;

    866:   PetscFunctionBegin;
    867:   NEPCheckSplit(extop->nep,1);
    868:   proj = extop->proj;
    869:   if (!proj) {
    870:     /* Initialize the projection data structure */
    871:     PetscCall(PetscNew(&proj));
    872:     extop->proj = proj;
    873:     proj->extop = extop;
    874:     PetscCall(BVGetSizes(Vext,NULL,NULL,&dim));
    875:     proj->dim = dim;
    876:     if (extop->szd) {
    877:       proj->lwork = 3*dim*dim+2*extop->szd*extop->szd+extop->szd;
    878:       PetscCall(PetscMalloc3(dim*extop->szd,&proj->V2,nep->nt,&proj->V1pApX,proj->lwork,&proj->work));
    879:       for (j=0;j<nep->nt;j++) PetscCall(MatCreateSeqDense(PETSC_COMM_SELF,proj->dim,extop->szd,NULL,&proj->V1pApX[j]));
    880:       PetscCall(MatCreateSeqDense(PETSC_COMM_SELF,extop->szd,proj->dim,NULL,&proj->XpV1));
    881:       PetscCall(BVCreateVec(extop->X,&proj->w));
    882:       PetscCall(BVDuplicateResize(extop->X,proj->dim,&proj->V1));
    883:     }
    884:     PetscCall(DSNEPSetComputeMatrixFunction(ds,NEPDeflationDSNEPComputeMatrix,(void*)proj));
    885:   }

    887:   /* Split Vext in V1 and V2 */
    888:   if (extop->szd) {
    889:     for (j=j0;j<j1;j++) {
    890:       PetscCall(BVGetColumn(Vext,j,&ve));
    891:       PetscCall(BVGetColumn(proj->V1,j,&v));
    892:       PetscCall(NEPDeflationCopyToExtendedVec(extop,v,proj->V2+j*extop->szd,ve,PETSC_TRUE));
    893:       PetscCall(BVRestoreColumn(proj->V1,j,&v));
    894:       PetscCall(BVRestoreColumn(Vext,j,&ve));
    895:     }
    896:     V1 = proj->V1;
    897:   } else V1 = Vext;

    899:   /* Compute matrices V1^* A_i V1 */
    900:   PetscCall(BVSetActiveColumns(V1,j0,j1));
    901:   for (k=0;k<nep->nt;k++) {
    902:     PetscCall(DSGetMat(ds,DSMatExtra[k],&G));
    903:     PetscCall(BVMatProject(V1,nep->A[k],V1,G));
    904:     PetscCall(DSRestoreMat(ds,DSMatExtra[k],&G));
    905:   }

    907:   if (extop->n) {
    908:     if (extop->szd) {
    909:       /* Compute matrices V1^* A_i X  and V1^* X */
    910:       PetscCall(BVSetActiveColumns(extop->W,0,n));
    911:       for (k=0;k<nep->nt;k++) {
    912:         PetscCall(BVMatMult(extop->X,nep->A[k],extop->W));
    913:         PetscCall(BVDot(extop->W,V1,proj->V1pApX[k]));
    914:       }
    915:       PetscCall(BVDot(V1,extop->X,proj->XpV1));
    916:     }
    917:   }
    918:   PetscFunctionReturn(PETSC_SUCCESS);
    919: }