Actual source code: tfs.c
1: /*
2: Provides an interface to the Tufo-Fischer parallel direct solver
3: */
5: #include <petsc/private/pcimpl.h>
6: #include <../src/mat/impls/aij/mpi/mpiaij.h>
7: #include <../src/ksp/pc/impls/tfs/tfs.h>
9: typedef struct {
10: xxt_ADT xxt;
11: xyt_ADT xyt;
12: Vec b,xd,xo;
13: PetscInt nd;
14: } PC_TFS;
16: PetscErrorCode PCDestroy_TFS(PC pc)
17: {
18: PC_TFS *tfs = (PC_TFS*)pc->data;
22: /* free the XXT datastructures */
23: if (tfs->xxt) {
24: XXT_free(tfs->xxt);
25: }
26: if (tfs->xyt) {
27: XYT_free(tfs->xyt);
28: }
29: VecDestroy(&tfs->b);
30: VecDestroy(&tfs->xd);
31: VecDestroy(&tfs->xo);
32: PetscFree(pc->data);
33: return(0);
34: }
36: static PetscErrorCode PCApply_TFS_XXT(PC pc,Vec x,Vec y)
37: {
38: PC_TFS *tfs = (PC_TFS*)pc->data;
39: PetscScalar *yy;
40: const PetscScalar *xx;
41: PetscErrorCode ierr;
44: VecGetArrayRead(x,&xx);
45: VecGetArray(y,&yy);
46: XXT_solve(tfs->xxt,yy,(PetscScalar*)xx);
47: VecRestoreArrayRead(x,&xx);
48: VecRestoreArray(y,&yy);
49: return(0);
50: }
52: static PetscErrorCode PCApply_TFS_XYT(PC pc,Vec x,Vec y)
53: {
54: PC_TFS *tfs = (PC_TFS*)pc->data;
55: PetscScalar *yy;
56: const PetscScalar *xx;
57: PetscErrorCode ierr;
60: VecGetArrayRead(x,&xx);
61: VecGetArray(y,&yy);
62: XYT_solve(tfs->xyt,yy,(PetscScalar*)xx);
63: VecRestoreArrayRead(x,&xx);
64: VecRestoreArray(y,&yy);
65: return(0);
66: }
68: static PetscErrorCode PCTFSLocalMult_TFS(PC pc,PetscScalar *xin,PetscScalar *xout)
69: {
70: PC_TFS *tfs = (PC_TFS*)pc->data;
71: Mat A = pc->pmat;
72: Mat_MPIAIJ *a = (Mat_MPIAIJ*)A->data;
76: VecPlaceArray(tfs->b,xout);
77: VecPlaceArray(tfs->xd,xin);
78: VecPlaceArray(tfs->xo,xin+tfs->nd);
79: MatMult(a->A,tfs->xd,tfs->b);
80: MatMultAdd(a->B,tfs->xo,tfs->b,tfs->b);
81: VecResetArray(tfs->b);
82: VecResetArray(tfs->xd);
83: VecResetArray(tfs->xo);
84: return(0);
85: }
87: static PetscErrorCode PCSetUp_TFS(PC pc)
88: {
89: PC_TFS *tfs = (PC_TFS*)pc->data;
90: Mat A = pc->pmat;
91: Mat_MPIAIJ *a = (Mat_MPIAIJ*)A->data;
93: PetscInt *localtoglobal,ncol,i;
94: PetscBool ismpiaij;
96: /*
97: PetscBool issymmetric;
98: Petsc Real tol = 0.0;
99: */
102: if (A->cmap->N != A->rmap->N) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_SIZ,"matrix must be square");
103: PetscObjectTypeCompare((PetscObject)pc->pmat,MATMPIAIJ,&ismpiaij);
104: if (!ismpiaij) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_SUP,"Currently only supports MPIAIJ matrices");
106: /* generate the local to global mapping */
107: ncol = a->A->cmap->n + a->B->cmap->n;
108: PetscMalloc1(ncol,&localtoglobal);
109: for (i=0; i<a->A->cmap->n; i++) localtoglobal[i] = A->cmap->rstart + i + 1;
110: for (i=0; i<a->B->cmap->n; i++) localtoglobal[i+a->A->cmap->n] = a->garray[i] + 1;
112: /* generate the vectors needed for the local solves */
113: VecCreateSeqWithArray(PETSC_COMM_SELF,1,a->A->rmap->n,NULL,&tfs->b);
114: VecCreateSeqWithArray(PETSC_COMM_SELF,1,a->A->cmap->n,NULL,&tfs->xd);
115: VecCreateSeqWithArray(PETSC_COMM_SELF,1,a->B->cmap->n,NULL,&tfs->xo);
116: tfs->nd = a->A->cmap->n;
118: /* MatIsSymmetric(A,tol,&issymmetric); */
119: /* if (issymmetric) { */
120: PetscBarrier((PetscObject)pc);
121: if (A->symmetric) {
122: tfs->xxt = XXT_new();
123: XXT_factor(tfs->xxt,localtoglobal,A->rmap->n,ncol,(PetscErrorCode (*)(void*,PetscScalar*,PetscScalar*))PCTFSLocalMult_TFS,pc);
124: pc->ops->apply = PCApply_TFS_XXT;
125: } else {
126: tfs->xyt = XYT_new();
127: XYT_factor(tfs->xyt,localtoglobal,A->rmap->n,ncol,(PetscErrorCode (*)(void*,PetscScalar*,PetscScalar*))PCTFSLocalMult_TFS,pc);
128: pc->ops->apply = PCApply_TFS_XYT;
129: }
131: PetscFree(localtoglobal);
132: return(0);
133: }
135: static PetscErrorCode PCSetFromOptions_TFS(PetscOptionItems *PetscOptionsObject,PC pc)
136: {
138: return(0);
139: }
140: static PetscErrorCode PCView_TFS(PC pc,PetscViewer viewer)
141: {
143: return(0);
144: }
146: /*MC
147: PCTFS - A parallel direct solver intended for problems with very few unknowns (like the
148: coarse grid in multigrid). Performs a Cholesky or LU factorization of a matrix defined by
149: its local matrix vector product.
151: Implemented by Henry M. Tufo III and Paul Fischer originally for Nek5000 and called XXT or XYT
153: Level: beginner
155: Notes:
156: Only implemented for the MPIAIJ matrices
158: Only works on a solver object that lives on all of PETSC_COMM_WORLD!
160: Only works for real numbers (is not built if PetscScalar is complex)
162: .seealso: PCCreate(), PCSetType(), PCType (for list of available types), PC
163: M*/
164: PETSC_EXTERN PetscErrorCode PCCreate_TFS(PC pc)
165: {
167: PC_TFS *tfs;
168: PetscMPIInt cmp;
171: MPI_Comm_compare(PETSC_COMM_WORLD,PetscObjectComm((PetscObject)pc),&cmp);
172: if (cmp != MPI_IDENT && cmp != MPI_CONGRUENT) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_SUP,"TFS only works with PETSC_COMM_WORLD objects");
173: PetscNewLog(pc,&tfs);
175: tfs->xxt = NULL;
176: tfs->xyt = NULL;
177: tfs->b = NULL;
178: tfs->xd = NULL;
179: tfs->xo = NULL;
180: tfs->nd = 0;
182: pc->ops->apply = NULL;
183: pc->ops->applytranspose = NULL;
184: pc->ops->setup = PCSetUp_TFS;
185: pc->ops->destroy = PCDestroy_TFS;
186: pc->ops->setfromoptions = PCSetFromOptions_TFS;
187: pc->ops->view = PCView_TFS;
188: pc->ops->applyrichardson = NULL;
189: pc->ops->applysymmetricleft = NULL;
190: pc->ops->applysymmetricright = NULL;
191: pc->data = (void*)tfs;
192: return(0);
193: }