Actual source code: trlan.c
2: /*
3: This file implements a wrapper to the TRLAN package
4: */
5: #include src/eps/impls/trlan/trlanp.h
7: /* Nasty global variable to access EPS data from TRLan_ */
8: static EPS globaleps;
12: PetscErrorCode EPSSetUp_TRLAN(EPS eps)
13: {
15: PetscInt n;
16: EPS_TRLAN *tr = (EPS_TRLAN *)eps->data;
19: VecGetSize(eps->vec_initial,&n);
20: if (eps->ncv) {
21: if (eps->ncv<eps->nev) SETERRQ(1,"The value of ncv must be at least nev");
22: }
23: else eps->ncv = eps->nev;
24: if (!eps->max_it) eps->max_it = PetscMax(100,n);
25: if (!eps->tol) eps->tol = 1.e-7;
26:
27: if (!eps->ishermitian)
28: SETERRQ(PETSC_ERR_SUP,"Requested method is only available for Hermitian problems");
30: if (eps->isgeneralized)
31: SETERRQ(PETSC_ERR_SUP,"Requested method is not available for generalized problems");
33: tr->restart = 0;
34: VecGetLocalSize(eps->vec_initial,&n);
35: tr->maxlan = eps->nev+PetscMin(eps->nev,6);
36: if (tr->maxlan+1-eps->ncv<=0) tr->lwork = tr->maxlan*(tr->maxlan+10);
37: else tr->lwork = n*(tr->maxlan+1-eps->ncv) + tr->maxlan*(tr->maxlan+10);
38: PetscMalloc(tr->lwork*sizeof(PetscReal),&tr->work);
40: EPSAllocateSolutionContiguous(eps);
41: return(0);
42: }
46: static int MatMult_TRLAN(int *n,int *m,PetscReal *xin,int *ldx,PetscReal *yout,int *ldy)
47: {
49: Vec x,y;
50: int i;
53: VecCreateMPIWithArray(globaleps->comm,*n,PETSC_DECIDE,PETSC_NULL,&x);
54: VecCreateMPIWithArray(globaleps->comm,*n,PETSC_DECIDE,PETSC_NULL,&y);
55: for (i=0;i<*m;i++) {
56: VecPlaceArray(x,(PetscScalar*)xin+i*(*ldx));
57: VecPlaceArray(y,(PetscScalar*)yout+i*(*ldy));
58: STApply(globaleps->OP,x,y);
59: EPSOrthogonalize(globaleps,globaleps->nds,globaleps->DS,y,PETSC_NULL,PETSC_NULL,PETSC_NULL);
60: VecResetArray(x);
61: VecResetArray(y);
62: }
63: return(0);
64: }
68: PetscErrorCode EPSSolve_TRLAN(EPS eps)
69: {
71: PetscInt nn;
72: int ipar[32], i, n, lohi, stat;
73: EPS_TRLAN *tr = (EPS_TRLAN *)eps->data;
74: PetscScalar *pV;
75:
78: VecGetLocalSize(eps->vec_initial,&nn);
79: n = nn;
80:
81: if (eps->which==EPS_LARGEST_REAL) lohi = 1;
82: else if (eps->which==EPS_SMALLEST_REAL) lohi = -1;
83: else SETERRQ(1,"Wrong value of eps->which");
85: globaleps = eps;
87: ipar[0] = 0; /* stat: error flag */
88: ipar[1] = lohi; /* smallest (lohi<0) or largest eigenvalues (lohi>0) */
89: ipar[2] = eps->nev; /* number of desired eigenpairs */
90: ipar[3] = 0; /* number of eigenpairs already converged */
91: ipar[4] = tr->maxlan; /* maximum Lanczos basis size */
92: ipar[5] = tr->restart; /* restarting scheme */
93: ipar[6] = eps->max_it; /* maximum number of MATVECs */
94: ipar[7] = MPI_Comm_c2f(eps->comm); /* communicator */
95: ipar[8] = 0; /* verboseness */
96: ipar[9] = 99; /* Fortran IO unit number used to write log messages */
97: ipar[10] = 1; /* use supplied starting vector */
98: ipar[11] = 0; /* checkpointing flag */
99: ipar[12] = 98; /* Fortran IO unit number used to write checkpoint files */
100: ipar[13] = 0; /* number of flops per matvec per PE (not used) */
101: tr->work[0] = eps->tol; /* relative tolerance on residual norms */
103: for (i=0;i<eps->ncv;i++) eps->eigr[i]=0.0;
104: VecCopy(eps->vec_initial,eps->V[0]);
105: VecGetArray(eps->V[0],&pV);
107: TRLan_ ( MatMult_TRLAN, ipar, &n, &eps->ncv, eps->eigr, pV, &n, tr->work, &tr->lwork );
109: VecRestoreArray( eps->V[0], &pV );
111: stat = ipar[0];
112: eps->nconv = ipar[3];
113: eps->its = ipar[25];
114: eps->reason = EPS_CONVERGED_TOL;
115: for (i=0;i<eps->nconv;i++) eps->eigi[i]=0.0;
116:
117: if (stat!=0) { SETERRQ1(PETSC_ERR_LIB,"Error in TRLAN (code=%d)",stat);}
119: return(0);
120: }
124: PetscErrorCode EPSDestroy_TRLAN(EPS eps)
125: {
127: EPS_TRLAN *tr = (EPS_TRLAN *)eps->data;
131: PetscFree(tr->work);
132: PetscFree(eps->data);
133: EPSFreeSolutionContiguous(eps);
134: return(0);
135: }
140: PetscErrorCode EPSCreate_TRLAN(EPS eps)
141: {
143: EPS_TRLAN *trlan;
146: PetscNew(EPS_TRLAN,&trlan);
147: PetscLogObjectMemory(eps,sizeof(EPS_TRLAN));
148: eps->data = (void *) trlan;
149: eps->ops->solve = EPSSolve_TRLAN;
150: eps->ops->setup = EPSSetUp_TRLAN;
151: eps->ops->destroy = EPSDestroy_TRLAN;
152: eps->ops->backtransform = EPSBackTransform_Default;
153: eps->ops->computevectors = EPSComputeVectors_Default;
154: eps->which = EPS_LARGEST_REAL;
155: return(0);
156: }