xref: /petsc/src/mat/tests/ex18.c (revision efbe7e8a80d07327753dbe0b33efee01e046af3f)
1 static char help[] = "Tests the use of MatZeroRowsColumns() for parallel matrices.\n\
2 Contributed-by: Stephan Kramer <s.kramer@imperial.ac.uk>\n\n";
3 
4 #include <petscmat.h>
5 
6 int main(int argc,char **args)
7 {
8   Mat            A;
9   Vec            x, rhs, y;
10   PetscInt       i,j,k,b,m = 3,n,nlocal=2,bs=1,Ii,J;
11   PetscInt       *boundary_nodes, nboundary_nodes, *boundary_indices;
12   PetscMPIInt    rank,size;
13   PetscErrorCode ierr;
14   PetscScalar    v,v0,v1,v2,a0=0.1,a,rhsval, *boundary_values,diag = 1.0;
15   PetscReal      norm;
16   char           convname[64];
17   PetscBool      upwind = PETSC_FALSE, nonlocalBC = PETSC_FALSE, zerorhs = PETSC_TRUE, convert = PETSC_FALSE;
18 
19   ierr = PetscInitialize(&argc,&args,(char*)0,help);if (ierr) return ierr;
20   ierr = MPI_Comm_rank(PETSC_COMM_WORLD,&rank);CHKERRQ(ierr);
21   ierr = MPI_Comm_size(PETSC_COMM_WORLD,&size);CHKERRQ(ierr);
22   n = nlocal*size;
23 
24   ierr = PetscOptionsGetInt(NULL,NULL, "-bs", &bs, NULL);CHKERRQ(ierr);
25   ierr = PetscOptionsGetBool(NULL,NULL, "-nonlocal_bc", &nonlocalBC, NULL);CHKERRQ(ierr);
26   ierr = PetscOptionsGetScalar(NULL,NULL, "-diag", &diag, NULL);CHKERRQ(ierr);
27   ierr = PetscOptionsGetString(NULL,NULL,"-convname",convname,sizeof(convname),&convert);CHKERRQ(ierr);
28   ierr = PetscOptionsGetBool(NULL,NULL, "-zerorhs", &zerorhs, NULL);CHKERRQ(ierr);
29 
30   ierr = MatCreate(PETSC_COMM_WORLD,&A);CHKERRQ(ierr);
31   ierr = MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,m*n*bs,m*n*bs);CHKERRQ(ierr);
32   ierr = MatSetFromOptions(A);CHKERRQ(ierr);
33   ierr = MatSetUp(A);CHKERRQ(ierr);
34 
35   ierr = MatCreateVecs(A, NULL, &rhs);CHKERRQ(ierr);
36   ierr = VecSetFromOptions(rhs);CHKERRQ(ierr);
37   ierr = VecSetUp(rhs);CHKERRQ(ierr);
38 
39   rhsval = 0.0;
40   for (i=0; i<m; i++) {
41     for (j=nlocal*rank; j<nlocal*(rank+1); j++) {
42       a = a0;
43       for (b=0; b<bs; b++) {
44         /* let's start with a 5-point stencil diffusion term */
45         v = -1.0;  Ii = (j + n*i)*bs + b;
46         if (i>0)   {J = Ii - n*bs; ierr = MatSetValues(A,1,&Ii,1,&J,&v,ADD_VALUES);CHKERRQ(ierr);}
47         if (i<m-1) {J = Ii + n*bs; ierr = MatSetValues(A,1,&Ii,1,&J,&v,ADD_VALUES);CHKERRQ(ierr);}
48         if (j>0)   {J = Ii - 1*bs; ierr = MatSetValues(A,1,&Ii,1,&J,&v,ADD_VALUES);CHKERRQ(ierr);}
49         if (j<n-1) {J = Ii + 1*bs; ierr = MatSetValues(A,1,&Ii,1,&J,&v,ADD_VALUES);CHKERRQ(ierr);}
50         v = 4.0; ierr = MatSetValues(A,1,&Ii,1,&Ii,&v,ADD_VALUES);CHKERRQ(ierr);
51         if (upwind) {
52           /* now add a 2nd order upwind advection term to add a little asymmetry */
53           if (j>2) {
54             J = Ii-2*bs; v2 = 0.5*a; v1 = -2.0*a; v0 = 1.5*a;
55             ierr = MatSetValues(A,1,&Ii,1,&J,&v2,ADD_VALUES);CHKERRQ(ierr);
56           } else {
57             /* fall back to 1st order upwind */
58             v1 = -1.0*a; v0 = 1.0*a;
59           };
60           if (j>1) {J = Ii-1*bs; ierr = MatSetValues(A,1,&Ii,1,&J,&v1,ADD_VALUES);CHKERRQ(ierr);}
61           ierr = MatSetValues(A,1,&Ii,1,&Ii,&v0,ADD_VALUES);CHKERRQ(ierr);
62           a /= 10.; /* use a different velocity for the next component */
63           /* add a coupling to the previous and next components */
64           v = 0.5;
65           if (b>0) {J = Ii - 1; ierr = MatSetValues(A,1,&Ii,1,&J,&v,ADD_VALUES);CHKERRQ(ierr);}
66           if (b<bs-1) {J = Ii + 1; ierr = MatSetValues(A,1,&Ii,1,&J,&v,ADD_VALUES);CHKERRQ(ierr);}
67         }
68         /* make up some rhs */
69         ierr = VecSetValue(rhs, Ii, rhsval, INSERT_VALUES);CHKERRQ(ierr);
70         rhsval += 1.0;
71       }
72     }
73   }
74   ierr = MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
75   ierr = MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
76 
77   if (convert) { /* Test different Mat implementations */
78     Mat B;
79 
80     ierr = MatConvert(A,convname,MAT_INITIAL_MATRIX,&B);CHKERRQ(ierr);
81     ierr = MatDestroy(&A);CHKERRQ(ierr);
82     A    = B;
83   }
84 
85   ierr = VecAssemblyBegin(rhs);CHKERRQ(ierr);
86   ierr = VecAssemblyEnd(rhs);CHKERRQ(ierr);
87   /* set rhs to zero to simplify */
88   if (zerorhs) {
89     ierr = VecZeroEntries(rhs);CHKERRQ(ierr);
90   }
91 
92   if (nonlocalBC) {
93     /*version where boundary conditions are set by processes that don't necessarily own the nodes */
94     if (!rank) {
95       nboundary_nodes = size>m ? nlocal : m-size+nlocal;
96       ierr = PetscMalloc1(nboundary_nodes,&boundary_nodes);CHKERRQ(ierr);
97       k = 0;
98       for (i=size; i<m; i++,k++) {boundary_nodes[k] = n*i;};
99     } else if (rank < m) {
100       nboundary_nodes = nlocal+1;
101       ierr = PetscMalloc1(nboundary_nodes,&boundary_nodes);CHKERRQ(ierr);
102       boundary_nodes[0] = rank*n;
103       k = 1;
104     } else {
105       nboundary_nodes = nlocal;
106       ierr = PetscMalloc1(nboundary_nodes,&boundary_nodes);CHKERRQ(ierr);
107       k = 0;
108     }
109     for (j=nlocal*rank; j<nlocal*(rank+1); j++,k++) {boundary_nodes[k] = j;};
110   } else {
111     /*version where boundary conditions are set by the node owners only */
112     ierr = PetscMalloc1(m*n,&boundary_nodes);CHKERRQ(ierr);
113     k=0;
114     for (j=0; j<n; j++) {
115       Ii = j;
116       if (Ii>=rank*m*nlocal && Ii<(rank+1)*m*nlocal) boundary_nodes[k++] = Ii;
117     }
118     for (i=1; i<m; i++) {
119       Ii = n*i;
120       if (Ii>=rank*m*nlocal && Ii<(rank+1)*m*nlocal) boundary_nodes[k++] = Ii;
121     }
122     nboundary_nodes = k;
123   }
124 
125   ierr = VecDuplicate(rhs, &x);CHKERRQ(ierr);
126   ierr = VecZeroEntries(x);CHKERRQ(ierr);
127   ierr = PetscMalloc2(nboundary_nodes*bs,&boundary_indices,nboundary_nodes*bs,&boundary_values);CHKERRQ(ierr);
128   for (k=0; k<nboundary_nodes; k++) {
129     Ii = boundary_nodes[k]*bs;
130     v = 1.0*boundary_nodes[k];
131     for (b=0; b<bs; b++, Ii++) {
132       boundary_indices[k*bs+b] = Ii;
133       boundary_values[k*bs+b] = v;
134       ierr = PetscSynchronizedPrintf(PETSC_COMM_WORLD, "%d %D %f\n", rank, Ii, (double)PetscRealPart(v));CHKERRQ(ierr);
135       v += 0.1;
136     }
137   }
138   ierr = PetscSynchronizedFlush(PETSC_COMM_WORLD, NULL);CHKERRQ(ierr);
139   ierr = VecSetValues(x, nboundary_nodes*bs, boundary_indices, boundary_values, INSERT_VALUES);CHKERRQ(ierr);
140   ierr = VecAssemblyBegin(x);CHKERRQ(ierr);
141   ierr = VecAssemblyEnd(x);CHKERRQ(ierr);
142 
143   /* We can check the rhs returned by MatZeroColumns by computing y=rhs-A*x  and overwriting the boundary entries with boundary values */
144   ierr = VecDuplicate(x, &y);CHKERRQ(ierr);
145   ierr = MatMult(A, x, y);CHKERRQ(ierr);
146   ierr = VecAYPX(y, -1.0, rhs);CHKERRQ(ierr);
147   for (k=0; k<nboundary_nodes*bs; k++) boundary_values[k] *= diag;
148   ierr = VecSetValues(y, nboundary_nodes*bs, boundary_indices, boundary_values, INSERT_VALUES);CHKERRQ(ierr);
149   ierr = VecAssemblyBegin(y);CHKERRQ(ierr);
150   ierr = VecAssemblyEnd(y);CHKERRQ(ierr);
151 
152   ierr = PetscPrintf(PETSC_COMM_WORLD, "*** Matrix A and vector x:\n");CHKERRQ(ierr);
153   ierr = MatView(A, PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
154   ierr = VecView(x,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
155 
156   ierr = MatZeroRowsColumns(A, nboundary_nodes*bs, boundary_indices, diag, x, rhs);CHKERRQ(ierr);
157   ierr = PetscPrintf(PETSC_COMM_WORLD, "*** Vector rhs returned by MatZeroRowsColumns\n");CHKERRQ(ierr);
158   ierr = VecView(rhs,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
159   ierr = VecAXPY(y, -1.0, rhs);CHKERRQ(ierr);
160   ierr = VecNorm(y, NORM_INFINITY, &norm);CHKERRQ(ierr);
161   if (norm > 1.0e-10) {
162     ierr = PetscPrintf(PETSC_COMM_WORLD, "*** Difference between rhs and y, inf-norm: %f\n", (double)norm);CHKERRQ(ierr);
163     ierr = VecView(y,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
164     SETERRQ(PETSC_COMM_WORLD, PETSC_ERR_PLIB, "Bug in MatZeroRowsColumns");
165   }
166 
167   ierr = PetscFree(boundary_nodes);CHKERRQ(ierr);
168   ierr = PetscFree2(boundary_indices,boundary_values);CHKERRQ(ierr);
169   ierr = VecDestroy(&x);CHKERRQ(ierr);
170   ierr = VecDestroy(&y);CHKERRQ(ierr);
171   ierr = VecDestroy(&rhs);CHKERRQ(ierr);
172   ierr = MatDestroy(&A);CHKERRQ(ierr);
173 
174   ierr = PetscFinalize();
175   return ierr;
176 }
177 
178 
179 /*TEST
180 
181    test:
182       diff_args: -j
183       suffix: 0
184 
185    test:
186       diff_args: -j
187       suffix: 1
188       nsize: 2
189 
190    test:
191       diff_args: -j
192       suffix: 10
193       nsize: 2
194       args: -bs 2 -nonlocal_bc
195 
196    test:
197       diff_args: -j
198       suffix: 11
199       nsize: 7
200       args: -bs 2 -nonlocal_bc
201 
202    test:
203       diff_args: -j
204       suffix: 12
205       args: -bs 2 -nonlocal_bc -mat_type baij
206 
207    test:
208       diff_args: -j
209       suffix: 13
210       nsize: 2
211       args: -bs 2 -nonlocal_bc -mat_type baij
212 
213    test:
214       diff_args: -j
215       suffix: 14
216       nsize: 7
217       args: -bs 2 -nonlocal_bc -mat_type baij
218 
219    test:
220       diff_args: -j
221       suffix: 2
222       nsize: 7
223 
224    test:
225       diff_args: -j
226       suffix: 3
227       args: -mat_type baij
228 
229    test:
230       diff_args: -j
231       suffix: 4
232       nsize: 2
233       args: -mat_type baij
234 
235    test:
236       diff_args: -j
237       suffix: 5
238       nsize: 7
239       args: -mat_type baij
240 
241    test:
242       diff_args: -j
243       suffix: 6
244       args: -bs 2 -mat_type baij
245 
246    test:
247       diff_args: -j
248       suffix: 7
249       nsize: 2
250       args: -bs 2 -mat_type baij
251 
252    test:
253       diff_args: -j
254       suffix: 8
255       nsize: 7
256       args: -bs 2 -mat_type baij
257 
258    test:
259       diff_args: -j
260       suffix: 9
261       args: -bs 2 -nonlocal_bc
262 
263    test:
264       diff_args: -j
265       suffix: 15
266       args: -bs 2 -nonlocal_bc -convname shell
267 
268    test:
269       diff_args: -j
270       suffix: 16
271       nsize: 2
272       args: -bs 2 -nonlocal_bc -convname shell
273 
274    test:
275       diff_args: -j
276       suffix: 17
277       args: -bs 2 -nonlocal_bc -convname dense
278 
279    testset:
280       diff_args: -j
281       suffix: full
282       nsize: {{1 3}separate output}
283       args: -diag {{0.12 -0.13}separate output} -convname {{aij shell baij}separate output} -zerorhs 0
284 
285    test:
286       diff_args: -j
287       requires: cuda
288       suffix: cusparse_1
289       nsize: 1
290       args: -diag {{0.12 -0.13}separate output} -convname {{seqaijcusparse mpiaijcusparse}separate output} -zerorhs 0 -mat_type {{seqaijcusparse mpiaijcusparse}separate output}
291 
292    test:
293       diff_args: -j
294       requires: cuda
295       suffix: cusparse_3
296       nsize: 3
297       args: -diag {{0.12 -0.13}separate output} -convname mpiaijcusparse -zerorhs 0 -mat_type mpiaijcusparse
298 
299 TEST*/
300