xref: /petsc/src/mat/tests/ex108.c (revision ebead697dbf761eb322f829370bbe90b3bd93fa3)
1 static char help[] = "Testing MatCreateSeqBAIJWithArrays() and MatCreateSeqSBAIJWithArrays().\n\n";
2 
3 #include <petscmat.h>
4 
5 int main(int argc,char **argv)
6 {
7   Mat            A,B,As;
8   const PetscInt *ai,*aj;
9   PetscInt       i,j,k,nz,n,asi[]={0,2,3,4,6,7};
10   PetscInt       asj[]={0,4,1,2,3,4,4};
11   PetscScalar    asa[7],*aa;
12   PetscRandom    rctx;
13   PetscMPIInt    size;
14   PetscBool      flg;
15 
16   PetscFunctionBeginUser;
17   PetscCall(PetscInitialize(&argc,&argv,(char*)0,help));
18   PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD,&size));
19   PetscCheck(size == 1,PETSC_COMM_WORLD,PETSC_ERR_WRONG_MPI_SIZE,"This is a uniprocessor example only!");
20 
21   /* Create a aij matrix for checking */
22   PetscCall(MatCreateSeqAIJ(PETSC_COMM_SELF,5,5,2,NULL,&A));
23   PetscCall(PetscRandomCreate(PETSC_COMM_WORLD,&rctx));
24   PetscCall(PetscRandomSetFromOptions(rctx));
25 
26   k = 0;
27   for (i=0; i<5; i++) {
28     nz = asi[i+1] - asi[i];  /* length of i_th row of A */
29     for (j=0; j<nz; j++) {
30       PetscCall(PetscRandomGetValue(rctx,&asa[k]));
31       PetscCall(MatSetValues(A,1,&i,1,&asj[k],&asa[k],INSERT_VALUES));
32       PetscCall(MatSetValues(A,1,&i,1,&asj[k],&asa[k],INSERT_VALUES));
33       if (i != asj[k]) { /* insert symmetric entry */
34         PetscCall(MatSetValues(A,1,&asj[k],1,&i,&asa[k],INSERT_VALUES));
35       }
36       k++;
37     }
38   }
39   PetscCall(MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY));
40   PetscCall(MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY));
41 
42   /* Create a baij matrix using MatCreateSeqBAIJWithArrays() */
43   PetscCall(MatGetRowIJ(A,0,PETSC_FALSE,PETSC_FALSE,&n,&ai,&aj,&flg));
44   PetscCall(MatSeqAIJGetArray(A,&aa));
45   /* WARNING: This sharing is dangerous if either A or B is later assembled */
46   PetscCall(MatCreateSeqBAIJWithArrays(PETSC_COMM_SELF,1,5,5,(PetscInt*)ai,(PetscInt*)aj,aa,&B));
47   PetscCall(MatSeqAIJRestoreArray(A,&aa));
48   PetscCall(MatRestoreRowIJ(A,0,PETSC_FALSE,PETSC_FALSE,&n,&ai,&aj,&flg));
49   PetscCall(MatMultEqual(A,B,10,&flg));
50   PetscCheck(flg,PETSC_COMM_SELF,PETSC_ERR_ARG_NOTSAMETYPE,"MatMult(A,B) are NOT equal");
51 
52   /* Create a sbaij matrix using MatCreateSeqSBAIJWithArrays() */
53   PetscCall(MatCreateSeqSBAIJWithArrays(PETSC_COMM_SELF,1,5,5,asi,asj,asa,&As));
54   PetscCall(MatMultEqual(A,As,10,&flg));
55   PetscCheck(flg,PETSC_COMM_SELF,PETSC_ERR_ARG_NOTSAMETYPE,"MatMult(A,As) are NOT equal");
56 
57   /* Free spaces */
58   PetscCall(PetscRandomDestroy(&rctx));
59   PetscCall(MatDestroy(&A));
60   PetscCall(MatDestroy(&B));
61   PetscCall(MatDestroy(&As));
62   PetscCall(PetscFinalize());
63   return 0;
64 }
65