Actual source code: trlan.c
1: /*
2: This file implements a wrapper to the TRLAN package
4: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
5: SLEPc - Scalable Library for Eigenvalue Problem Computations
6: Copyright (c) 2002-2010, Universidad Politecnica de Valencia, Spain
8: This file is part of SLEPc.
9:
10: SLEPc is free software: you can redistribute it and/or modify it under the
11: terms of version 3 of the GNU Lesser General Public License as published by
12: the Free Software Foundation.
14: SLEPc is distributed in the hope that it will be useful, but WITHOUT ANY
15: WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
16: FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for
17: more details.
19: You should have received a copy of the GNU Lesser General Public License
20: along with SLEPc. If not, see <http://www.gnu.org/licenses/>.
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22: */
24: #include src/eps/impls/external/trlan/trlanp.h
26: PetscErrorCode EPSSolve_TRLAN(EPS);
28: /* Nasty global variable to access EPS data from TRLan_ */
29: static EPS globaleps;
33: PetscErrorCode EPSSetUp_TRLAN(EPS eps)
34: {
36: EPS_TRLAN *tr = (EPS_TRLAN *)eps->data;
39: if (eps->ncv) {
40: if (eps->ncv<eps->nev) SETERRQ(1,"The value of ncv must be at least nev");
41: }
42: else eps->ncv = eps->nev;
43: if (eps->mpd) PetscInfo(eps,"Warning: parameter mpd ignored\n");
44: if (!eps->max_it) eps->max_it = PetscMax(1000,eps->n);
45:
46: if (!eps->ishermitian)
47: SETERRQ(PETSC_ERR_SUP,"Requested method is only available for Hermitian problems");
49: if (eps->isgeneralized)
50: SETERRQ(PETSC_ERR_SUP,"Requested method is not available for generalized problems");
52: if (!eps->which) eps->which = EPS_LARGEST_REAL;
53: if (eps->which!=EPS_LARGEST_REAL && eps->which!=EPS_SMALLEST_REAL && eps->which!=EPS_TARGET_REAL)
54: SETERRQ(1,"Wrong value of eps->which");
56: tr->restart = 0;
57: tr->maxlan = PetscBLASIntCast(eps->nev+PetscMin(eps->nev,6));
58: if (tr->maxlan+1-eps->ncv<=0) { tr->lwork = PetscBLASIntCast(tr->maxlan*(tr->maxlan+10)); }
59: else { tr->lwork = PetscBLASIntCast(eps->nloc*(tr->maxlan+1-eps->ncv) + tr->maxlan*(tr->maxlan+10)); }
60: PetscMalloc(tr->lwork*sizeof(PetscReal),&tr->work);
62: if (eps->extraction) {
63: PetscInfo(eps,"Warning: extraction type ignored\n");
64: }
66: EPSAllocateSolution(eps);
68: /* dispatch solve method */
69: if (eps->leftvecs) SETERRQ(PETSC_ERR_SUP,"Left vectors not supported in this solver");
70: eps->ops->solve = EPSSolve_TRLAN;
71: return(0);
72: }
76: static PetscBLASInt MatMult_TRLAN(PetscBLASInt *n,PetscBLASInt *m,PetscReal *xin,PetscBLASInt *ldx,PetscReal *yout,PetscBLASInt *ldy)
77: {
79: Vec x,y;
80: PetscBLASInt i;
83: VecCreateMPIWithArray(((PetscObject)globaleps)->comm,*n,PETSC_DECIDE,PETSC_NULL,&x);
84: VecCreateMPIWithArray(((PetscObject)globaleps)->comm,*n,PETSC_DECIDE,PETSC_NULL,&y);
85: for (i=0;i<*m;i++) {
86: VecPlaceArray(x,(PetscScalar*)xin+i*(*ldx));
87: VecPlaceArray(y,(PetscScalar*)yout+i*(*ldy));
88: STApply(globaleps->OP,x,y);
89: IPOrthogonalize(globaleps->ip,0,PETSC_NULL,globaleps->nds,PETSC_NULL,globaleps->DS,y,PETSC_NULL,PETSC_NULL,PETSC_NULL);
90: VecResetArray(x);
91: VecResetArray(y);
92: }
93: VecDestroy(x);
94: VecDestroy(y);
95: return(0);
96: }
100: PetscErrorCode EPSSolve_TRLAN(EPS eps)
101: {
103: PetscInt i;
104: PetscBLASInt ipar[32], n, lohi, stat, ncv;
105: EPS_TRLAN *tr = (EPS_TRLAN *)eps->data;
106: PetscScalar *pV;
107:
110: ncv = PetscBLASIntCast(eps->ncv);
111: n = PetscBLASIntCast(eps->nloc);
112:
113: if (eps->which==EPS_LARGEST_REAL || eps->which==EPS_TARGET_REAL) lohi = 1;
114: else if (eps->which==EPS_SMALLEST_REAL) lohi = -1;
115: else SETERRQ(1,"Wrong value of eps->which");
117: globaleps = eps;
119: ipar[0] = 0; /* stat: error flag */
120: ipar[1] = lohi; /* smallest (lohi<0) or largest eigenvalues (lohi>0) */
121: ipar[2] = PetscBLASIntCast(eps->nev); /* number of desired eigenpairs */
122: ipar[3] = 0; /* number of eigenpairs already converged */
123: ipar[4] = tr->maxlan; /* maximum Lanczos basis size */
124: ipar[5] = tr->restart; /* restarting scheme */
125: ipar[6] = PetscBLASIntCast(eps->max_it); /* maximum number of MATVECs */
126: ipar[7] = PetscBLASIntCast(MPI_Comm_c2f(((PetscObject)eps)->comm)); /* communicator */
127: ipar[8] = 0; /* verboseness */
128: ipar[9] = 99; /* Fortran IO unit number used to write log messages */
129: ipar[10] = 1; /* use supplied starting vector */
130: ipar[11] = 0; /* checkpointing flag */
131: ipar[12] = 98; /* Fortran IO unit number used to write checkpoint files */
132: ipar[13] = 0; /* number of flops per matvec per PE (not used) */
133: tr->work[0] = eps->tol; /* relative tolerance on residual norms */
135: for (i=0;i<eps->ncv;i++) eps->eigr[i]=0.0;
136: EPSGetStartVector(eps,0,eps->V[0],PETSC_NULL);
137: VecGetArray(eps->V[0],&pV);
139: TRLan_ ( MatMult_TRLAN, ipar, &n, &ncv, eps->eigr, pV, &n, tr->work, &tr->lwork );
141: VecRestoreArray( eps->V[0], &pV );
143: stat = ipar[0];
144: eps->nconv = ipar[3];
145: eps->its = ipar[25];
146: eps->reason = EPS_CONVERGED_TOL;
147:
148: if (stat!=0) { SETERRQ1(PETSC_ERR_LIB,"Error in TRLAN (code=%d)",stat);}
150: return(0);
151: }
155: PetscErrorCode EPSDestroy_TRLAN(EPS eps)
156: {
158: EPS_TRLAN *tr = (EPS_TRLAN *)eps->data;
162: PetscFree(tr->work);
163: PetscFree(eps->data);
164: EPSFreeSolution(eps);
165: return(0);
166: }
171: PetscErrorCode EPSCreate_TRLAN(EPS eps)
172: {
174: EPS_TRLAN *trlan;
177: PetscNew(EPS_TRLAN,&trlan);
178: PetscLogObjectMemory(eps,sizeof(EPS_TRLAN));
179: eps->data = (void *) trlan;
180: eps->ops->setup = EPSSetUp_TRLAN;
181: eps->ops->destroy = EPSDestroy_TRLAN;
182: eps->ops->backtransform = EPSBackTransform_Default;
183: eps->ops->computevectors = EPSComputeVectors_Default;
184: return(0);
185: }