xref: /petsc/src/mat/tests/ex14.c (revision c4762a1b19cd2af06abeed90e8f9d34fb975dd94)
1*c4762a1bSJed Brown 
2*c4762a1bSJed Brown static char help[] = "Tests sequential and parallel MatGetRow() and MatRestoreRow().\n";
3*c4762a1bSJed Brown 
4*c4762a1bSJed Brown #include <petscmat.h>
5*c4762a1bSJed Brown 
6*c4762a1bSJed Brown int main(int argc,char **args)
7*c4762a1bSJed Brown {
8*c4762a1bSJed Brown   Mat               C;
9*c4762a1bSJed Brown   PetscInt          i,j,m = 5,n = 5,Ii,J,nz,rstart,rend;
10*c4762a1bSJed Brown   PetscErrorCode    ierr;
11*c4762a1bSJed Brown   PetscMPIInt       rank;
12*c4762a1bSJed Brown   const PetscInt    *idx;
13*c4762a1bSJed Brown   PetscScalar       v;
14*c4762a1bSJed Brown   const PetscScalar *values;
15*c4762a1bSJed Brown 
16*c4762a1bSJed Brown   ierr = PetscInitialize(&argc,&args,(char*)0,help);if (ierr) return ierr;
17*c4762a1bSJed Brown   /* Create the matrix for the five point stencil, YET AGAIN */
18*c4762a1bSJed Brown   ierr = MatCreate(PETSC_COMM_WORLD,&C);CHKERRQ(ierr);
19*c4762a1bSJed Brown   ierr = MatSetSizes(C,PETSC_DECIDE,PETSC_DECIDE,m*n,m*n);CHKERRQ(ierr);
20*c4762a1bSJed Brown   ierr = MatSetFromOptions(C);CHKERRQ(ierr);
21*c4762a1bSJed Brown   ierr = MatSetUp(C);CHKERRQ(ierr);
22*c4762a1bSJed Brown   for (i=0; i<m; i++) {
23*c4762a1bSJed Brown     for (j=0; j<n; j++) {
24*c4762a1bSJed Brown       v = -1.0;  Ii = j + n*i;
25*c4762a1bSJed Brown       if (i>0)   {J = Ii - n; ierr = MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);CHKERRQ(ierr);}
26*c4762a1bSJed Brown       if (i<m-1) {J = Ii + n; ierr = MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);CHKERRQ(ierr);}
27*c4762a1bSJed Brown       if (j>0)   {J = Ii - 1; ierr = MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);CHKERRQ(ierr);}
28*c4762a1bSJed Brown       if (j<n-1) {J = Ii + 1; ierr = MatSetValues(C,1,&Ii,1,&J,&v,INSERT_VALUES);CHKERRQ(ierr);}
29*c4762a1bSJed Brown       v = 4.0; ierr = MatSetValues(C,1,&Ii,1,&Ii,&v,INSERT_VALUES);CHKERRQ(ierr);
30*c4762a1bSJed Brown     }
31*c4762a1bSJed Brown   }
32*c4762a1bSJed Brown   ierr = MatAssemblyBegin(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
33*c4762a1bSJed Brown   ierr = MatAssemblyEnd(C,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
34*c4762a1bSJed Brown   ierr = MatView(C,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
35*c4762a1bSJed Brown 
36*c4762a1bSJed Brown   ierr = MPI_Comm_rank(PETSC_COMM_WORLD,&rank);CHKERRQ(ierr);
37*c4762a1bSJed Brown   ierr = MatGetOwnershipRange(C,&rstart,&rend);CHKERRQ(ierr);
38*c4762a1bSJed Brown   for (i=rstart; i<rend; i++) {
39*c4762a1bSJed Brown     ierr = MatGetRow(C,i,&nz,&idx,&values);CHKERRQ(ierr);
40*c4762a1bSJed Brown     if (!rank) {
41*c4762a1bSJed Brown       for (j=0; j<nz; j++) {
42*c4762a1bSJed Brown         ierr = PetscPrintf(PETSC_COMM_SELF,"%D %g ",idx[j],(double)PetscRealPart(values[j]));CHKERRQ(ierr);
43*c4762a1bSJed Brown       }
44*c4762a1bSJed Brown       ierr = PetscPrintf(PETSC_COMM_SELF,"\n");CHKERRQ(ierr);
45*c4762a1bSJed Brown     }
46*c4762a1bSJed Brown     ierr = MatRestoreRow(C,i,&nz,&idx,&values);CHKERRQ(ierr);
47*c4762a1bSJed Brown   }
48*c4762a1bSJed Brown 
49*c4762a1bSJed Brown   ierr = MatDestroy(&C);CHKERRQ(ierr);
50*c4762a1bSJed Brown   ierr = PetscFinalize();
51*c4762a1bSJed Brown   return ierr;
52*c4762a1bSJed Brown }
53*c4762a1bSJed Brown 
54*c4762a1bSJed Brown 
55*c4762a1bSJed Brown /*TEST
56*c4762a1bSJed Brown 
57*c4762a1bSJed Brown    test:
58*c4762a1bSJed Brown 
59*c4762a1bSJed Brown TEST*/
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