Date: 2021-09-20T09:44:02+00:00

Actual source code: svdscalap.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:    This file implements a wrapper to the ScaLAPACK SVD solver
     12: */

     14: #include <slepc/private/svdimpl.h>
     15: #include <slepc/private/slepcscalapack.h>

     17: typedef struct {
     18:   Mat As;        /* converted matrix */
     19: } SVD_ScaLAPACK;

     21: PetscErrorCode SVDSetUp_ScaLAPACK(SVD svd)
     22: {
     24:   SVD_ScaLAPACK  *ctx = (SVD_ScaLAPACK*)svd->data;
     25:   PetscInt       M,N;

     28:   SVDCheckStandard(svd);
     29:   MatGetSize(svd->A,&M,&N);
     30:   svd->ncv = N;
     31:   if (svd->mpd!=PETSC_DEFAULT) { PetscInfo(svd,"Warning: parameter mpd ignored\n"); }
     32:   if (svd->max_it==PETSC_DEFAULT) svd->max_it = 1;
     33:   svd->leftbasis = PETSC_TRUE;
     34:   SVDCheckUnsupported(svd,SVD_FEATURE_STOPPING);
     35:   SVDAllocateSolution(svd,0);

     37:   /* convert matrix */
     38:   MatDestroy(&ctx->As);
     39:   MatConvert(svd->OP,MATSCALAPACK,MAT_INITIAL_MATRIX,&ctx->As);
     40:   return(0);
     41: }

     43: PetscErrorCode SVDSolve_ScaLAPACK(SVD svd)
     44: {
     46:   SVD_ScaLAPACK  *ctx = (SVD_ScaLAPACK*)svd->data;
     47:   Mat            A = ctx->As,Z,Q,QT,U,V;
     48:   Mat_ScaLAPACK  *a = (Mat_ScaLAPACK*)A->data,*q,*z;
     49:   PetscScalar    *work,minlwork;
     50:   PetscBLASInt   info,lwork=-1,one=1;
     51:   PetscInt       M,N,m,n,mn;
     52: #if defined(PETSC_USE_COMPLEX)
     53:   PetscBLASInt   lrwork;
     54:   PetscReal      *rwork,dummy;
     55: #endif

     58:   MatGetSize(A,&M,&N);
     59:   MatGetLocalSize(A,&m,&n);
     60:   mn = (M>=N)? n: m;
     61:   MatCreate(PetscObjectComm((PetscObject)A),&Z);
     62:   MatSetSizes(Z,m,mn,PETSC_DECIDE,PETSC_DECIDE);
     63:   MatSetType(Z,MATSCALAPACK);
     64:   MatSetUp(Z);
     65:   MatAssemblyBegin(Z,MAT_FINAL_ASSEMBLY);
     66:   MatAssemblyEnd(Z,MAT_FINAL_ASSEMBLY);
     67:   z = (Mat_ScaLAPACK*)Z->data;
     68:   MatCreate(PetscObjectComm((PetscObject)A),&QT);
     69:   MatSetSizes(QT,mn,n,PETSC_DECIDE,PETSC_DECIDE);
     70:   MatSetType(QT,MATSCALAPACK);
     71:   MatSetUp(QT);
     72:   MatAssemblyBegin(QT,MAT_FINAL_ASSEMBLY);
     73:   MatAssemblyEnd(QT,MAT_FINAL_ASSEMBLY);
     74:   q = (Mat_ScaLAPACK*)QT->data;

     76:   PetscFPTrapPush(PETSC_FP_TRAP_OFF);
     77: #if !defined(PETSC_USE_COMPLEX)
     78:   /* allocate workspace */
     79:   PetscStackCallBLAS("SCALAPACKgesvd",SCALAPACKgesvd_("V","V",&a->M,&a->N,a->loc,&one,&one,a->desc,svd->sigma,z->loc,&one,&one,z->desc,q->loc,&one,&one,q->desc,&minlwork,&lwork,&info));
     81:   PetscBLASIntCast((PetscInt)minlwork,&lwork);
     82:   PetscMalloc1(lwork,&work);
     83:   /* call computational routine */
     84:   PetscStackCallBLAS("SCALAPACKgesvd",SCALAPACKgesvd_("V","V",&a->M,&a->N,a->loc,&one,&one,a->desc,svd->sigma,z->loc,&one,&one,z->desc,q->loc,&one,&one,q->desc,work,&lwork,&info));
     86:   PetscFree(work);
     87: #else
     88:   /* allocate workspace */
     89:   PetscStackCallBLAS("SCALAPACKgesvd",SCALAPACKgesvd_("V","V",&a->M,&a->N,a->loc,&one,&one,a->desc,svd->sigma,z->loc,&one,&one,z->desc,q->loc,&one,&one,q->desc,&minlwork,&lwork,&dummy,&info));
     91:   PetscBLASIntCast((PetscInt)PetscRealPart(minlwork),&lwork);
     92:   lrwork = 1+4*PetscMax(a->M,a->N);
     93:   PetscMalloc2(lwork,&work,lrwork,&rwork);
     94:   /* call computational routine */
     95:   PetscStackCallBLAS("SCALAPACKgesvd",SCALAPACKgesvd_("V","V",&a->M,&a->N,a->loc,&one,&one,a->desc,svd->sigma,z->loc,&one,&one,z->desc,q->loc,&one,&one,q->desc,work,&lwork,rwork,&info));
     97:   PetscFree2(work,rwork);
     98: #endif
     99:   PetscFPTrapPop();

    101:   MatHermitianTranspose(QT,MAT_INITIAL_MATRIX,&Q);
    102:   MatDestroy(&QT);
    103:   BVGetMat(svd->U,&U);
    104:   BVGetMat(svd->V,&V);
    105:   if (M>=N) {
    106:     MatConvert(Z,MATDENSE,MAT_REUSE_MATRIX,&U);
    107:     MatConvert(Q,MATDENSE,MAT_REUSE_MATRIX,&V);
    108:   } else {
    109:     MatConvert(Q,MATDENSE,MAT_REUSE_MATRIX,&U);
    110:     MatConvert(Z,MATDENSE,MAT_REUSE_MATRIX,&V);
    111:   }
    112:   BVRestoreMat(svd->U,&U);
    113:   BVRestoreMat(svd->V,&V);
    114:   MatDestroy(&Z);
    115:   MatDestroy(&Q);

    117:   svd->nconv  = svd->ncv;
    118:   svd->its    = 1;
    119:   svd->reason = SVD_CONVERGED_TOL;
    120:   return(0);
    121: }

    123: PetscErrorCode SVDDestroy_ScaLAPACK(SVD svd)
    124: {

    128:   PetscFree(svd->data);
    129:   return(0);
    130: }

    132: PetscErrorCode SVDReset_ScaLAPACK(SVD svd)
    133: {
    135:   SVD_ScaLAPACK  *ctx = (SVD_ScaLAPACK*)svd->data;

    138:   MatDestroy(&ctx->As);
    139:   return(0);
    140: }

    142: SLEPC_EXTERN PetscErrorCode SVDCreate_ScaLAPACK(SVD svd)
    143: {
    145:   SVD_ScaLAPACK  *ctx;

    148:   PetscNewLog(svd,&ctx);
    149:   svd->data = (void*)ctx;

    151:   svd->ops->solve          = SVDSolve_ScaLAPACK;
    152:   svd->ops->setup          = SVDSetUp_ScaLAPACK;
    153:   svd->ops->destroy        = SVDDestroy_ScaLAPACK;
    154:   svd->ops->reset          = SVDReset_ScaLAPACK;
    155:   return(0);
    156: }