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) 2002-2012, Universitat 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/>.
21: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
22: */
24: #include <slepc-private/epsimpl.h> /*I "slepceps.h" I*/
25: #include <../src/eps/impls/external/trlan/trlanp.h>
27: PetscErrorCode EPSSolve_TRLAN(EPS);
29: /* Nasty global variable to access EPS data from TRLan_ */
30: static EPS globaleps;
34: PetscErrorCode EPSSetUp_TRLAN(EPS eps)
35: {
37: EPS_TRLAN *tr = (EPS_TRLAN *)eps->data;
40: tr->maxlan = PetscBLASIntCast(PetscMax(7,eps->nev+PetscMin(eps->nev,6)));
41: if (eps->ncv) {
42: if (eps->ncv<eps->nev) SETERRQ(((PetscObject)eps)->comm,1,"The value of ncv must be at least nev");
43: }
44: else eps->ncv = tr->maxlan;
45: if (eps->mpd) { PetscInfo(eps,"Warning: parameter mpd ignored\n"); }
46: if (!eps->max_it) eps->max_it = PetscMax(1000,eps->n);
47:
48: if (!eps->ishermitian) SETERRQ(((PetscObject)eps)->comm,PETSC_ERR_SUP,"Requested method is only available for Hermitian problems");
50: if (eps->isgeneralized) SETERRQ(((PetscObject)eps)->comm,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) SETERRQ(((PetscObject)eps)->comm,1,"Wrong value of eps->which");
54: if (eps->arbit_func) SETERRQ(((PetscObject)eps)->comm,PETSC_ERR_SUP,"Arbitrary selection of eigenpairs not supported in this solver");
56: tr->restart = 0;
57: if (tr->maxlan+1-eps->ncv<=0) { tr->lwork = PetscBLASIntCast(tr->maxlan*(tr->maxlan+10)); }
58: else { tr->lwork = PetscBLASIntCast(eps->nloc*(tr->maxlan+1-eps->ncv) + tr->maxlan*(tr->maxlan+10)); }
59: PetscMalloc(tr->lwork*sizeof(PetscReal),&tr->work);
61: if (eps->extraction) { PetscInfo(eps,"Warning: extraction type ignored\n"); }
63: EPSAllocateSolution(eps);
65: /* dispatch solve method */
66: if (eps->leftvecs) SETERRQ(((PetscObject)eps)->comm,PETSC_ERR_SUP,"Left vectors not supported in this solver");
67: eps->ops->solve = EPSSolve_TRLAN;
68: return(0);
69: }
73: static PetscBLASInt MatMult_TRLAN(PetscBLASInt *n,PetscBLASInt *m,PetscReal *xin,PetscBLASInt *ldx,PetscReal *yout,PetscBLASInt *ldy)
74: {
76: Vec x,y;
77: PetscBLASInt i;
80: VecCreateMPIWithArray(((PetscObject)globaleps)->comm,1,*n,PETSC_DECIDE,PETSC_NULL,&x);
81: VecCreateMPIWithArray(((PetscObject)globaleps)->comm,1,*n,PETSC_DECIDE,PETSC_NULL,&y);
82: for (i=0;i<*m;i++) {
83: VecPlaceArray(x,(PetscScalar*)xin+i*(*ldx));
84: VecPlaceArray(y,(PetscScalar*)yout+i*(*ldy));
85: STApply(globaleps->OP,x,y);
86: IPOrthogonalize(globaleps->ip,0,PETSC_NULL,globaleps->nds,PETSC_NULL,globaleps->defl,y,PETSC_NULL,PETSC_NULL,PETSC_NULL);
87: VecResetArray(x);
88: VecResetArray(y);
89: }
90: VecDestroy(&x);
91: VecDestroy(&y);
92: return(0);
93: }
97: PetscErrorCode EPSSolve_TRLAN(EPS eps)
98: {
100: PetscInt i;
101: PetscBLASInt ipar[32],n,lohi,stat,ncv;
102: EPS_TRLAN *tr = (EPS_TRLAN *)eps->data;
103: PetscScalar *pV;
104:
106: ncv = PetscBLASIntCast(eps->ncv);
107: n = PetscBLASIntCast(eps->nloc);
108:
109: if (eps->which==EPS_LARGEST_REAL || eps->which==EPS_TARGET_REAL) lohi = 1;
110: else if (eps->which==EPS_SMALLEST_REAL) lohi = -1;
111: else SETERRQ(((PetscObject)eps)->comm,1,"Wrong value of eps->which");
113: globaleps = eps;
115: ipar[0] = 0; /* stat: error flag */
116: ipar[1] = lohi; /* smallest (lohi<0) or largest eigenvalues (lohi>0) */
117: ipar[2] = PetscBLASIntCast(eps->nev); /* number of desired eigenpairs */
118: ipar[3] = 0; /* number of eigenpairs already converged */
119: ipar[4] = tr->maxlan; /* maximum Lanczos basis size */
120: ipar[5] = tr->restart; /* restarting scheme */
121: ipar[6] = PetscBLASIntCast(eps->max_it); /* maximum number of MATVECs */
122: ipar[7] = PetscBLASIntCast(MPI_Comm_c2f(((PetscObject)eps)->comm)); /* communicator */
123: ipar[8] = 0; /* verboseness */
124: ipar[9] = 99; /* Fortran IO unit number used to write log messages */
125: ipar[10] = 1; /* use supplied starting vector */
126: ipar[11] = 0; /* checkpointing flag */
127: ipar[12] = 98; /* Fortran IO unit number used to write checkpoint files */
128: ipar[13] = 0; /* number of flops per matvec per PE (not used) */
129: tr->work[0] = eps->tol; /* relative tolerance on residual norms */
131: for (i=0;i<eps->ncv;i++) eps->eigr[i]=0.0;
132: EPSGetStartVector(eps,0,eps->V[0],PETSC_NULL);
133: VecGetArray(eps->V[0],&pV);
135: TRLan_(MatMult_TRLAN,ipar,&n,&ncv,eps->eigr,pV,&n,tr->work,&tr->lwork);
137: VecRestoreArray(eps->V[0],&pV);
139: stat = ipar[0];
140: eps->nconv = ipar[3];
141: eps->its = ipar[25];
142: eps->reason = EPS_CONVERGED_TOL;
143:
144: if (stat!=0) SETERRQ1(((PetscObject)eps)->comm,PETSC_ERR_LIB,"Error in TRLAN (code=%d)",stat);
145: return(0);
146: }
150: PetscErrorCode EPSReset_TRLAN(EPS eps)
151: {
153: EPS_TRLAN *tr = (EPS_TRLAN *)eps->data;
156: PetscFree(tr->work);
157: EPSFreeSolution(eps);
158: return(0);
159: }
163: PetscErrorCode EPSDestroy_TRLAN(EPS eps)
164: {
168: PetscFree(eps->data);
169: return(0);
170: }
172: EXTERN_C_BEGIN
175: PetscErrorCode EPSCreate_TRLAN(EPS eps)
176: {
180: PetscNewLog(eps,EPS_TRLAN,&eps->data);
181: eps->ops->setup = EPSSetUp_TRLAN;
182: eps->ops->destroy = EPSDestroy_TRLAN;
183: eps->ops->reset = EPSReset_TRLAN;
184: eps->ops->backtransform = EPSBackTransform_Default;
185: eps->ops->computevectors = EPSComputeVectors_Default;
186: return(0);
187: }
188: EXTERN_C_END