Actual source code: trlan.c
slepc-3.18.1 2022-11-02
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);
47: EPSAllocateSolution(eps,0);
48: return 0;
49: }
51: static PetscBLASInt MatMult_TRLAN(PetscBLASInt *n,PetscBLASInt *m,PetscReal *xin,PetscBLASInt *ldx,PetscReal *yout,PetscBLASInt *ldy)
52: {
53: Vec x=globaldata.x,y=globaldata.y;
54: EPS eps=globaldata.eps;
55: PetscBLASInt i;
57: for (i=0;i<*m;i++) {
58: VecPlaceArray(x,(PetscScalar*)xin+i*(*ldx));
59: VecPlaceArray(y,(PetscScalar*)yout+i*(*ldy));
60: STApply(eps->st,x,y);
61: BVOrthogonalizeVec(eps->V,y,NULL,NULL,NULL);
62: VecResetArray(x);
63: VecResetArray(y);
64: }
65: return 0;
66: }
68: PetscErrorCode EPSSolve_TRLAN(EPS eps)
69: {
70: PetscInt i;
71: PetscBLASInt ipar[32],n,lohi,stat,ncv;
72: EPS_TRLAN *tr = (EPS_TRLAN*)eps->data;
73: PetscScalar *pV;
74: Vec v0;
75: Mat A;
76: #if !defined(PETSC_HAVE_MPIUNI)
77: MPI_Fint fcomm;
78: #endif
80: PetscBLASIntCast(eps->ncv,&ncv);
81: PetscBLASIntCast(eps->nloc,&n);
84: lohi = (eps->which==EPS_SMALLEST_REAL)? -1: 1;
86: globaldata.eps = eps;
87: STGetMatrix(eps->st,0,&A);
88: MatCreateVecsEmpty(A,&globaldata.x,&globaldata.y);
90: ipar[0] = 0; /* stat: error flag */
91: ipar[1] = lohi; /* smallest (lohi<0) or largest eigenvalues (lohi>0) */
92: PetscBLASIntCast(eps->nev,&ipar[2]); /* number of desired eigenpairs */
93: ipar[3] = 0; /* number of eigenpairs already converged */
94: ipar[4] = tr->maxlan; /* maximum Lanczos basis size */
95: ipar[5] = tr->restart; /* restarting scheme */
96: PetscBLASIntCast(eps->max_it,&ipar[6]); /* maximum number of MATVECs */
97: #if !defined(PETSC_HAVE_MPIUNI)
98: fcomm = MPI_Comm_c2f(PetscObjectComm((PetscObject)eps));
99: ipar[7] = fcomm;
100: #endif
101: ipar[8] = 0; /* verboseness */
102: ipar[9] = 99; /* Fortran IO unit number used to write log messages */
103: ipar[10] = 1; /* use supplied starting vector */
104: ipar[11] = 0; /* checkpointing flag */
105: ipar[12] = 98; /* Fortran IO unit number used to write checkpoint files */
106: ipar[13] = 0; /* number of flops per matvec per PE (not used) */
107: tr->work[0] = eps->tol; /* relative tolerance on residual norms */
109: for (i=0;i<eps->ncv;i++) eps->eigr[i]=0.0;
110: EPSGetStartVector(eps,0,NULL);
111: BVSetActiveColumns(eps->V,0,0); /* just for deflation space */
112: BVGetColumn(eps->V,0,&v0);
113: VecGetArray(v0,&pV);
115: PetscStackCallExternalVoid("TRLan",TRLan_(MatMult_TRLAN,ipar,&n,&ncv,eps->eigr,pV,&n,tr->work,&tr->lwork));
117: VecRestoreArray(v0,&pV);
118: BVRestoreColumn(eps->V,0,&v0);
120: stat = ipar[0];
121: eps->nconv = ipar[3];
122: eps->its = ipar[25];
123: eps->reason = EPS_CONVERGED_TOL;
125: VecDestroy(&globaldata.x);
126: VecDestroy(&globaldata.y);
128: return 0;
129: }
131: PetscErrorCode EPSReset_TRLAN(EPS eps)
132: {
133: EPS_TRLAN *tr = (EPS_TRLAN*)eps->data;
135: PetscFree(tr->work);
136: return 0;
137: }
139: PetscErrorCode EPSDestroy_TRLAN(EPS eps)
140: {
141: PetscFree(eps->data);
142: return 0;
143: }
145: SLEPC_EXTERN PetscErrorCode EPSCreate_TRLAN(EPS eps)
146: {
147: EPS_TRLAN *ctx;
149: PetscNew(&ctx);
150: eps->data = (void*)ctx;
152: eps->ops->solve = EPSSolve_TRLAN;
153: eps->ops->setup = EPSSetUp_TRLAN;
154: eps->ops->setupsort = EPSSetUpSort_Basic;
155: eps->ops->destroy = EPSDestroy_TRLAN;
156: eps->ops->reset = EPSReset_TRLAN;
157: eps->ops->backtransform = EPSBackTransform_Default;
158: return 0;
159: }