Actual source code: trlan.c
slepc-3.17.1 2022-04-11
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: */
10: /*
11: This file implements a wrapper to the TRLAN package
12: */
14: #include <slepc/private/epsimpl.h>
15: #include "trlan.h"
17: /* Nasty global variable to access EPS data from TRLan_ */
18: static struct {
19: EPS eps;
20: Vec x,y;
21: } globaldata;
23: PetscErrorCode EPSSetUp_TRLAN(EPS eps)
24: {
25: EPS_TRLAN *tr = (EPS_TRLAN*)eps->data;
27: EPSCheckHermitian(eps);
28: EPSCheckStandard(eps);
29: PetscBLASIntCast(PetscMax(7,eps->nev+PetscMin(eps->nev,6)),&tr->maxlan);
30: if (eps->ncv!=PETSC_DEFAULT) {
32: } else eps->ncv = tr->maxlan;
33: if (eps->mpd!=PETSC_DEFAULT) PetscInfo(eps,"Warning: parameter mpd ignored\n");
34: if (eps->max_it==PETSC_DEFAULT) eps->max_it = PetscMax(1000,eps->n);
36: if (!eps->which) eps->which = EPS_LARGEST_REAL;
38: EPSCheckUnsupported(eps,EPS_FEATURE_ARBITRARY | EPS_FEATURE_REGION | EPS_FEATURE_CONVERGENCE | EPS_FEATURE_STOPPING);
39: EPSCheckIgnored(eps,EPS_FEATURE_BALANCE | EPS_FEATURE_EXTRACTION);
41: tr->restart = 0;
42: if (tr->maxlan+1-eps->ncv<=0) PetscBLASIntCast(tr->maxlan*(tr->maxlan+10),&tr->lwork);
43: else PetscBLASIntCast(eps->nloc*(tr->maxlan+1-eps->ncv) + tr->maxlan*(tr->maxlan+10),&tr->lwork);
44: if (tr->work) PetscFree(tr->work);
45: PetscMalloc1(tr->lwork,&tr->work);
46: PetscLogObjectMemory((PetscObject)eps,tr->lwork*sizeof(PetscReal));
48: EPSAllocateSolution(eps,0);
49: PetscFunctionReturn(0);
50: }
52: static PetscBLASInt MatMult_TRLAN(PetscBLASInt *n,PetscBLASInt *m,PetscReal *xin,PetscBLASInt *ldx,PetscReal *yout,PetscBLASInt *ldy)
53: {
54: Vec x=globaldata.x,y=globaldata.y;
55: EPS eps=globaldata.eps;
56: PetscBLASInt i;
58: for (i=0;i<*m;i++) {
59: VecPlaceArray(x,(PetscScalar*)xin+i*(*ldx));
60: VecPlaceArray(y,(PetscScalar*)yout+i*(*ldy));
61: STApply(eps->st,x,y);
62: BVOrthogonalizeVec(eps->V,y,NULL,NULL,NULL);
63: VecResetArray(x);
64: VecResetArray(y);
65: }
66: PetscFunctionReturn(0);
67: }
69: PetscErrorCode EPSSolve_TRLAN(EPS eps)
70: {
71: PetscInt i;
72: PetscBLASInt ipar[32],n,lohi,stat,ncv;
73: EPS_TRLAN *tr = (EPS_TRLAN*)eps->data;
74: PetscScalar *pV;
75: Vec v0;
76: Mat A;
77: #if !defined(PETSC_HAVE_MPIUNI)
78: MPI_Fint fcomm;
79: #endif
81: PetscBLASIntCast(eps->ncv,&ncv);
82: PetscBLASIntCast(eps->nloc,&n);
85: lohi = (eps->which==EPS_SMALLEST_REAL)? -1: 1;
87: globaldata.eps = eps;
88: STGetMatrix(eps->st,0,&A);
89: MatCreateVecsEmpty(A,&globaldata.x,&globaldata.y);
91: ipar[0] = 0; /* stat: error flag */
92: ipar[1] = lohi; /* smallest (lohi<0) or largest eigenvalues (lohi>0) */
93: PetscBLASIntCast(eps->nev,&ipar[2]); /* number of desired eigenpairs */
94: ipar[3] = 0; /* number of eigenpairs already converged */
95: ipar[4] = tr->maxlan; /* maximum Lanczos basis size */
96: ipar[5] = tr->restart; /* restarting scheme */
97: PetscBLASIntCast(eps->max_it,&ipar[6]); /* maximum number of MATVECs */
98: #if !defined(PETSC_HAVE_MPIUNI)
99: fcomm = MPI_Comm_c2f(PetscObjectComm((PetscObject)eps));
100: ipar[7] = fcomm;
101: #endif
102: ipar[8] = 0; /* verboseness */
103: ipar[9] = 99; /* Fortran IO unit number used to write log messages */
104: ipar[10] = 1; /* use supplied starting vector */
105: ipar[11] = 0; /* checkpointing flag */
106: ipar[12] = 98; /* Fortran IO unit number used to write checkpoint files */
107: ipar[13] = 0; /* number of flops per matvec per PE (not used) */
108: tr->work[0] = eps->tol; /* relative tolerance on residual norms */
110: for (i=0;i<eps->ncv;i++) eps->eigr[i]=0.0;
111: EPSGetStartVector(eps,0,NULL);
112: BVSetActiveColumns(eps->V,0,0); /* just for deflation space */
113: BVGetColumn(eps->V,0,&v0);
114: VecGetArray(v0,&pV);
116: PetscStackCall("TRLan",TRLan_(MatMult_TRLAN,ipar,&n,&ncv,eps->eigr,pV,&n,tr->work,&tr->lwork));
118: VecRestoreArray(v0,&pV);
119: BVRestoreColumn(eps->V,0,&v0);
121: stat = ipar[0];
122: eps->nconv = ipar[3];
123: eps->its = ipar[25];
124: eps->reason = EPS_CONVERGED_TOL;
126: VecDestroy(&globaldata.x);
127: VecDestroy(&globaldata.y);
129: PetscFunctionReturn(0);
130: }
132: PetscErrorCode EPSReset_TRLAN(EPS eps)
133: {
134: EPS_TRLAN *tr = (EPS_TRLAN*)eps->data;
136: PetscFree(tr->work);
137: PetscFunctionReturn(0);
138: }
140: PetscErrorCode EPSDestroy_TRLAN(EPS eps)
141: {
142: PetscFree(eps->data);
143: PetscFunctionReturn(0);
144: }
146: SLEPC_EXTERN PetscErrorCode EPSCreate_TRLAN(EPS eps)
147: {
148: EPS_TRLAN *ctx;
150: PetscNewLog(eps,&ctx);
151: eps->data = (void*)ctx;
153: eps->ops->solve = EPSSolve_TRLAN;
154: eps->ops->setup = EPSSetUp_TRLAN;
155: eps->ops->setupsort = EPSSetUpSort_Basic;
156: eps->ops->destroy = EPSDestroy_TRLAN;
157: eps->ops->reset = EPSReset_TRLAN;
158: eps->ops->backtransform = EPSBackTransform_Default;
159: PetscFunctionReturn(0);
160: }