Actual source code: svdscalap.c
slepc-3.14.2 2021-02-01
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: 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: SVDMatGetSize(svd,&M,&N);
29: svd->ncv = N;
30: if (svd->mpd!=PETSC_DEFAULT) { PetscInfo(svd,"Warning: parameter mpd ignored\n"); }
31: if (svd->max_it==PETSC_DEFAULT) svd->max_it = 1;
32: svd->leftbasis = PETSC_TRUE;
33: SVDCheckUnsupported(svd,SVD_FEATURE_STOPPING);
34: SVDAllocateSolution(svd,0);
36: /* convert matrix */
37: MatDestroy(&ctx->As);
38: MatConvert(svd->OP,MATSCALAPACK,MAT_INITIAL_MATRIX,&ctx->As);
39: return(0);
40: }
42: PetscErrorCode SVDSolve_ScaLAPACK(SVD svd)
43: {
45: SVD_ScaLAPACK *ctx = (SVD_ScaLAPACK*)svd->data;
46: Mat A = ctx->As,Z,Q,QT,U,V;
47: Mat_ScaLAPACK *a = (Mat_ScaLAPACK*)A->data,*q,*z;
48: PetscScalar *work,minlwork;
49: PetscBLASInt info,lwork=-1,one=1;
50: PetscInt M,N,m,n,mn;
51: #if defined(PETSC_USE_COMPLEX)
52: PetscBLASInt lrwork;
53: PetscReal *rwork,dummy;
54: #endif
57: MatGetSize(A,&M,&N);
58: MatGetLocalSize(A,&m,&n);
59: mn = (M>=N)? n: m;
60: MatCreate(PetscObjectComm((PetscObject)A),&Z);
61: MatSetSizes(Z,m,mn,PETSC_DECIDE,PETSC_DECIDE);
62: MatSetType(Z,MATSCALAPACK);
63: MatSetUp(Z);
64: MatAssemblyBegin(Z,MAT_FINAL_ASSEMBLY);
65: MatAssemblyEnd(Z,MAT_FINAL_ASSEMBLY);
66: z = (Mat_ScaLAPACK*)Z->data;
67: MatCreate(PetscObjectComm((PetscObject)A),&QT);
68: MatSetSizes(QT,mn,n,PETSC_DECIDE,PETSC_DECIDE);
69: MatSetType(QT,MATSCALAPACK);
70: MatSetUp(QT);
71: MatAssemblyBegin(QT,MAT_FINAL_ASSEMBLY);
72: MatAssemblyEnd(QT,MAT_FINAL_ASSEMBLY);
73: q = (Mat_ScaLAPACK*)QT->data;
75: #if !defined(PETSC_USE_COMPLEX)
76: /* allocate workspace */
77: 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));
79: PetscBLASIntCast((PetscInt)minlwork,&lwork);
80: PetscMalloc1(lwork,&work);
81: /* call computational routine */
82: 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));
84: PetscFree(work);
85: #else
86: /* allocate workspace */
87: 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));
89: PetscBLASIntCast((PetscInt)PetscRealPart(minlwork),&lwork);
90: lrwork = 1+4*PetscMax(a->M,a->N);
91: PetscMalloc2(lwork,&work,lrwork,&rwork);
92: /* call computational routine */
93: 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));
95: PetscFree2(work,rwork);
96: #endif
98: MatHermitianTranspose(QT,MAT_INITIAL_MATRIX,&Q);
99: MatDestroy(&QT);
100: BVGetMat(svd->U,&U);
101: BVGetMat(svd->V,&V);
102: if (M>=N) {
103: MatConvert(Z,MATDENSE,MAT_REUSE_MATRIX,&U);
104: MatConvert(Q,MATDENSE,MAT_REUSE_MATRIX,&V);
105: } else {
106: MatConvert(Q,MATDENSE,MAT_REUSE_MATRIX,&U);
107: MatConvert(Z,MATDENSE,MAT_REUSE_MATRIX,&V);
108: }
109: BVRestoreMat(svd->U,&U);
110: BVRestoreMat(svd->V,&V);
111: MatDestroy(&Z);
112: MatDestroy(&Q);
114: svd->nconv = svd->ncv;
115: svd->its = 1;
116: svd->reason = SVD_CONVERGED_TOL;
117: return(0);
118: }
120: PetscErrorCode SVDDestroy_ScaLAPACK(SVD svd)
121: {
125: PetscFree(svd->data);
126: return(0);
127: }
129: PetscErrorCode SVDReset_ScaLAPACK(SVD svd)
130: {
132: SVD_ScaLAPACK *ctx = (SVD_ScaLAPACK*)svd->data;
135: MatDestroy(&ctx->As);
136: return(0);
137: }
139: SLEPC_EXTERN PetscErrorCode SVDCreate_ScaLAPACK(SVD svd)
140: {
142: SVD_ScaLAPACK *ctx;
145: PetscNewLog(svd,&ctx);
146: svd->data = (void*)ctx;
148: svd->ops->solve = SVDSolve_ScaLAPACK;
149: svd->ops->setup = SVDSetUp_ScaLAPACK;
150: svd->ops->destroy = SVDDestroy_ScaLAPACK;
151: svd->ops->reset = SVDReset_ScaLAPACK;
152: return(0);
153: }