Actual source code: ex26.c
1: static char help[] ="Solves Laplacian with multigrid. Tests block API for PCMG\n\
2: -mx <xg>, where <xg> = number of grid points in the x-direction\n\
3: -my <yg>, where <yg> = number of grid points in the y-direction\n\
4: -Nx <npx>, where <npx> = number of processors in the x-direction\n\
5: -Ny <npy>, where <npy> = number of processors in the y-direction\n\n";
7: /* Modified from ~src/ksp/tests/ex19.c. Used for testing ML 6.2 interface.
9: This problem is modeled by
10: the partial differential equation
12: -Laplacian u = g, 0 < x,y < 1,
14: with boundary conditions
16: u = 0 for x = 0, x = 1, y = 0, y = 1.
18: A finite difference approximation with the usual 5-point stencil
19: is used to discretize the boundary value problem to obtain a linear
20: system of equations.
22: Usage: ./ex26 -ksp_monitor_short -pc_type ml
23: -mg_coarse_ksp_max_it 10
24: -mg_levels_1_ksp_max_it 10 -mg_levels_2_ksp_max_it 10
25: -mg_fine_ksp_max_it 10
26: */
28: #include <petscksp.h>
29: #include <petscdm.h>
30: #include <petscdmda.h>
32: /* User-defined application contexts */
33: typedef struct {
34: PetscInt mx,my; /* number grid points in x and y direction */
35: Vec localX,localF; /* local vectors with ghost region */
36: DM da;
37: Vec x,b,r; /* global vectors */
38: Mat J; /* Jacobian on grid */
39: Mat A,P,R;
40: KSP ksp;
41: } GridCtx;
43: static PetscErrorCode FormJacobian_Grid(GridCtx*,Mat);
45: int main(int argc,char **argv)
46: {
47: PetscInt i,its,Nx=PETSC_DECIDE,Ny=PETSC_DECIDE,nlocal,nrhs = 1;
48: PetscScalar one = 1.0;
49: Mat A,B,X;
50: GridCtx fine_ctx;
51: KSP ksp;
52: PetscBool Brand = PETSC_FALSE,flg;
54: PetscInitialize(&argc,&argv,(char*)0,help);
55: /* set up discretization matrix for fine grid */
56: fine_ctx.mx = 9;
57: fine_ctx.my = 9;
58: PetscOptionsGetInt(NULL,NULL,"-mx",&fine_ctx.mx,NULL);
59: PetscOptionsGetInt(NULL,NULL,"-my",&fine_ctx.my,NULL);
60: PetscOptionsGetInt(NULL,NULL,"-nrhs",&nrhs,NULL);
61: PetscOptionsGetInt(NULL,NULL,"-Nx",&Nx,NULL);
62: PetscOptionsGetInt(NULL,NULL,"-Ny",&Ny,NULL);
63: PetscOptionsGetBool(NULL,NULL,"-rand",&Brand,NULL);
64: PetscPrintf(PETSC_COMM_WORLD,"Fine grid size %D by %D\n",fine_ctx.mx,fine_ctx.my);
66: /* Set up distributed array for fine grid */
67: DMDACreate2d(PETSC_COMM_WORLD, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE,DMDA_STENCIL_STAR,fine_ctx.mx,fine_ctx.my,Nx,Ny,1,1,NULL,NULL,&fine_ctx.da);
68: DMSetFromOptions(fine_ctx.da);
69: DMSetUp(fine_ctx.da);
70: DMCreateGlobalVector(fine_ctx.da,&fine_ctx.x);
71: VecDuplicate(fine_ctx.x,&fine_ctx.b);
72: VecGetLocalSize(fine_ctx.x,&nlocal);
73: DMCreateLocalVector(fine_ctx.da,&fine_ctx.localX);
74: VecDuplicate(fine_ctx.localX,&fine_ctx.localF);
75: DMCreateMatrix(fine_ctx.da,&A);
76: FormJacobian_Grid(&fine_ctx,A);
78: /* create linear solver */
79: KSPCreate(PETSC_COMM_WORLD,&ksp);
80: KSPSetDM(ksp,fine_ctx.da);
81: KSPSetDMActive(ksp,PETSC_FALSE);
83: /* set values for rhs vector */
84: VecSet(fine_ctx.b,one);
86: /* set options, then solve system */
87: KSPSetFromOptions(ksp); /* calls PCSetFromOptions_ML if 'pc_type=ml' */
88: KSPSetOperators(ksp,A,A);
89: KSPSolve(ksp,fine_ctx.b,fine_ctx.x);
90: VecViewFromOptions(fine_ctx.x,NULL,"-debug");
91: KSPGetIterationNumber(ksp,&its);
92: KSPGetIterationNumber(ksp,&its);
93: PetscPrintf(PETSC_COMM_WORLD,"Number of iterations = %D\n",its);
95: /* test multiple right-hand side */
96: MatCreateDense(PETSC_COMM_WORLD,nlocal,PETSC_DECIDE,fine_ctx.mx*fine_ctx.my,nrhs,NULL,&B);
97: MatSetOptionsPrefix(B,"rhs_");
98: MatSetFromOptions(B);
99: MatDuplicate(B,MAT_DO_NOT_COPY_VALUES,&X);
100: if (Brand) {
101: MatSetRandom(B,NULL);
102: } else {
103: PetscScalar *b;
105: MatDenseGetArrayWrite(B,&b);
106: for (i=0;i<nlocal*nrhs;i++) b[i] = 1.0;
107: MatDenseRestoreArrayWrite(B,&b);
108: MatAssemblyBegin(B,MAT_FINAL_ASSEMBLY);
109: MatAssemblyEnd(B,MAT_FINAL_ASSEMBLY);
110: }
111: KSPMatSolve(ksp,B,X);
112: MatViewFromOptions(X,NULL,"-debug");
114: PetscObjectTypeCompare((PetscObject)ksp,KSPPREONLY,&flg);
115: if ((flg || nrhs == 1) && !Brand) {
116: PetscInt n;
117: const PetscScalar *xx,*XX;
119: VecGetArrayRead(fine_ctx.x,&xx);
120: MatDenseGetArrayRead(X,&XX);
121: for (n=0;n<nrhs;n++) {
122: for (i=0;i<nlocal;i++) {
123: if (PetscAbsScalar(xx[i] - XX[nlocal*n + i]) > PETSC_SMALL) {
124: PetscPrintf(PETSC_COMM_SELF,"[%d] Error local solve %D, entry %D -> %g + i %g != %g + i %g\n",PetscGlobalRank,n,i,(double)PetscRealPart(xx[i]),(double)PetscImaginaryPart(xx[i]),(double)PetscRealPart(XX[i]),(double)PetscImaginaryPart(XX[i]));
125: }
126: }
127: }
128: MatDenseRestoreArrayRead(X,&XX);
129: VecRestoreArrayRead(fine_ctx.x,&xx);
130: }
132: /* free data structures */
133: VecDestroy(&fine_ctx.x);
134: VecDestroy(&fine_ctx.b);
135: DMDestroy(&fine_ctx.da);
136: VecDestroy(&fine_ctx.localX);
137: VecDestroy(&fine_ctx.localF);
138: MatDestroy(&A);
139: MatDestroy(&B);
140: MatDestroy(&X);
141: KSPDestroy(&ksp);
143: PetscFinalize();
144: return 0;
145: }
147: PetscErrorCode FormJacobian_Grid(GridCtx *grid,Mat jac)
148: {
149: PetscInt i,j,row,mx,my,xs,ys,xm,ym,Xs,Ys,Xm,Ym,col[5];
150: PetscInt grow;
151: const PetscInt *ltog;
152: PetscScalar two = 2.0,one = 1.0,v[5],hx,hy,hxdhy,hydhx,value;
153: ISLocalToGlobalMapping ltogm;
156: mx = grid->mx; my = grid->my;
157: hx = one/(PetscReal)(mx-1); hy = one/(PetscReal)(my-1);
158: hxdhy = hx/hy; hydhx = hy/hx;
160: /* Get ghost points */
161: DMDAGetCorners(grid->da,&xs,&ys,0,&xm,&ym,0);
162: DMDAGetGhostCorners(grid->da,&Xs,&Ys,0,&Xm,&Ym,0);
163: DMGetLocalToGlobalMapping(grid->da,<ogm);
164: ISLocalToGlobalMappingGetIndices(ltogm,<og);
166: /* Evaluate Jacobian of function */
167: for (j=ys; j<ys+ym; j++) {
168: row = (j - Ys)*Xm + xs - Xs - 1;
169: for (i=xs; i<xs+xm; i++) {
170: row++;
171: grow = ltog[row];
172: if (i > 0 && i < mx-1 && j > 0 && j < my-1) {
173: v[0] = -hxdhy; col[0] = ltog[row - Xm];
174: v[1] = -hydhx; col[1] = ltog[row - 1];
175: v[2] = two*(hydhx + hxdhy); col[2] = grow;
176: v[3] = -hydhx; col[3] = ltog[row + 1];
177: v[4] = -hxdhy; col[4] = ltog[row + Xm];
178: MatSetValues(jac,1,&grow,5,col,v,INSERT_VALUES);
179: } else if ((i > 0 && i < mx-1) || (j > 0 && j < my-1)) {
180: value = .5*two*(hydhx + hxdhy);
181: MatSetValues(jac,1,&grow,1,&grow,&value,INSERT_VALUES);
182: } else {
183: value = .25*two*(hydhx + hxdhy);
184: MatSetValues(jac,1,&grow,1,&grow,&value,INSERT_VALUES);
185: }
186: }
187: }
188: ISLocalToGlobalMappingRestoreIndices(ltogm,<og);
189: MatAssemblyBegin(jac,MAT_FINAL_ASSEMBLY);
190: MatAssemblyEnd(jac,MAT_FINAL_ASSEMBLY);
191: return 0;
192: }
194: /*TEST
196: test:
197: args: -ksp_monitor_short
199: test:
200: suffix: 2
201: args: -ksp_monitor_short
202: nsize: 3
204: test:
205: suffix: ml_1
206: args: -ksp_monitor_short -pc_type ml -mat_no_inode
207: nsize: 3
208: requires: ml
210: test:
211: suffix: ml_2
212: args: -ksp_monitor_short -pc_type ml -mat_no_inode -ksp_max_it 3
213: nsize: 3
214: requires: ml
216: test:
217: suffix: ml_3
218: args: -ksp_monitor_short -pc_type ml -mat_no_inode -pc_mg_type ADDITIVE -ksp_max_it 7
219: nsize: 1
220: requires: ml
222: test:
223: suffix: cycles
224: nsize: {{1 2}}
225: args: -ksp_view_final_residual -pc_type mg -mx 5 -my 5 -pc_mg_levels 3 -pc_mg_galerkin -ksp_monitor -mg_levels_ksp_type richardson -mg_levels_pc_type jacobi -pc_mg_type {{additive multiplicative full kaskade}separate output} -nrhs 1
227: test:
228: suffix: matcycles
229: nsize: {{1 2}}
230: args: -ksp_view_final_residual -ksp_type preonly -pc_type mg -mx 5 -my 5 -pc_mg_levels 3 -pc_mg_galerkin -ksp_monitor -mg_levels_ksp_type richardson -mg_levels_pc_type jacobi -pc_mg_type {{additive multiplicative full kaskade}separate output} -nrhs 7 -ksp_matsolve_batch_size {{4 7}separate output}
232: test:
233: requires: ml
234: suffix: matcycles_ml
235: nsize: {{1 2}}
236: args: -ksp_view_final_residual -ksp_type preonly -pc_type ml -mx 5 -my 5 -ksp_monitor -mg_levels_ksp_type richardson -mg_levels_pc_type jacobi -pc_mg_type {{additive multiplicative full kaskade}separate output} -nrhs 7 -ksp_matsolve_batch_size {{4 7}separate output}
238: testset:
239: requires: hpddm
240: args: -ksp_view_final_residual -ksp_type hpddm -pc_type mg -pc_mg_levels 3 -pc_mg_galerkin -mx 5 -my 5 -ksp_monitor -mg_levels_ksp_type richardson -mg_levels_pc_type jacobi -nrhs 7
241: test:
242: suffix: matcycles_hpddm_mg
243: nsize: {{1 2}}
244: args: -pc_mg_type {{additive multiplicative full kaskade}separate output} -ksp_matsolve_batch_size {{4 7}separate output}
245: test:
246: suffix: hpddm_mg_mixed_precision
247: nsize: 2
248: output_file: output/ex26_matcycles_hpddm_mg_pc_mg_type-multiplicative_ksp_matsolve_batch_size-4.out
249: args: -ksp_matsolve_batch_size 4 -ksp_hpddm_precision {{single double}shared output}
251: test:
252: requires: hpddm
253: nsize: {{1 2}}
254: suffix: matcycles_hpddm_ilu
255: args: -ksp_view_final_residual -ksp_type hpddm -pc_type redundant -redundant_pc_type ilu -mx 5 -my 5 -ksp_monitor -nrhs 7 -ksp_matsolve_batch_size {{4 7}separate output}
257: TEST*/