xref: /petsc/src/mat/tests/ex8.c (revision 5f80ce2ab25dff0f4601e710601cbbcecf323266)
1c4762a1bSJed Brown 
2c4762a1bSJed Brown static char help[] = "Tests automatic allocation of matrix storage space.\n\n";
3c4762a1bSJed Brown 
4c4762a1bSJed Brown #include <petscmat.h>
5c4762a1bSJed Brown 
6c4762a1bSJed Brown int main(int argc,char **args)
7c4762a1bSJed Brown {
8c4762a1bSJed Brown   Mat            C;
9c4762a1bSJed Brown   PetscInt       i,j,m = 3,n = 3,Ii,J;
10c4762a1bSJed Brown   PetscErrorCode ierr;
11c4762a1bSJed Brown   PetscScalar    v;
12c4762a1bSJed Brown   MatInfo        info;
13c4762a1bSJed Brown 
14c4762a1bSJed Brown   ierr = PetscInitialize(&argc,&args,(char*)0,help);if (ierr) return ierr;
15*5f80ce2aSJacob Faibussowitsch   CHKERRQ(PetscOptionsGetInt(NULL,NULL,"-m",&m,NULL));
16*5f80ce2aSJacob Faibussowitsch   CHKERRQ(PetscOptionsGetInt(NULL,NULL,"-n",&n,NULL));
17c4762a1bSJed Brown 
18c4762a1bSJed Brown   /* create the matrix for the five point stencil, YET AGAIN */
19*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatCreate(PETSC_COMM_SELF,&C));
20*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatSetSizes(C,PETSC_DECIDE,PETSC_DECIDE,m*n,m*n));
21*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatSetFromOptions(C));
22*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatSetUp(C));
23c4762a1bSJed Brown   for (i=0; i<m; i++) {
24c4762a1bSJed Brown     for (j=0; j<n; j++) {
25c4762a1bSJed Brown       v = -1.0;  Ii = j + n*i;
26*5f80ce2aSJacob Faibussowitsch       if (i>0)   {J=Ii-n; CHKERRQ(MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES));}
27*5f80ce2aSJacob Faibussowitsch       if (i<m-1) {J=Ii+n; CHKERRQ(MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES));}
28*5f80ce2aSJacob Faibussowitsch       if (j>0)   {J=Ii-1; CHKERRQ(MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES));}
29*5f80ce2aSJacob Faibussowitsch       if (j<n-1) {J=Ii+1; CHKERRQ(MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES));}
30*5f80ce2aSJacob Faibussowitsch       v = 4.0; CHKERRQ(MatSetValues(C,1,&Ii,1,&Ii,&v,INSERT_VALUES));
31c4762a1bSJed Brown     }
32c4762a1bSJed Brown   }
33*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY));
34*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY));
35*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatView(C,PETSC_VIEWER_STDOUT_SELF));
36c4762a1bSJed Brown 
37*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatGetInfo(C,MAT_LOCAL,&info));
38*5f80ce2aSJacob Faibussowitsch   CHKERRQ(PetscPrintf(PETSC_COMM_SELF,"matrix nonzeros = %" PetscInt_FMT ", allocated nonzeros = %" PetscInt_FMT "\n",(PetscInt)info.nz_used,(PetscInt)info.nz_allocated));
39c4762a1bSJed Brown 
40*5f80ce2aSJacob Faibussowitsch   CHKERRQ(MatDestroy(&C));
41c4762a1bSJed Brown   ierr = PetscFinalize();
42c4762a1bSJed Brown   return ierr;
43c4762a1bSJed Brown }
44c4762a1bSJed Brown 
45c4762a1bSJed Brown /*TEST
46c4762a1bSJed Brown 
47c4762a1bSJed Brown    test:
48c4762a1bSJed Brown 
49c4762a1bSJed Brown TEST*/
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