xref: /petsc/src/mat/tests/ex108.c (revision daa037dfd3c3bec8dc8659548d2b20b07c1dc6de)
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   PetscCall(PetscInitialize(&argc,&argv,(char*)0,help));
17   PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD,&size));
18   PetscCheck(size == 1,PETSC_COMM_WORLD,PETSC_ERR_WRONG_MPI_SIZE,"This is a uniprocessor example only!");
19 
20   /* Create a aij matrix for checking */
21   PetscCall(MatCreateSeqAIJ(PETSC_COMM_SELF,5,5,2,NULL,&A));
22   PetscCall(PetscRandomCreate(PETSC_COMM_WORLD,&rctx));
23   PetscCall(PetscRandomSetFromOptions(rctx));
24 
25   k = 0;
26   for (i=0; i<5; i++) {
27     nz = asi[i+1] - asi[i];  /* length of i_th row of A */
28     for (j=0; j<nz; j++) {
29       PetscCall(PetscRandomGetValue(rctx,&asa[k]));
30       PetscCall(MatSetValues(A,1,&i,1,&asj[k],&asa[k],INSERT_VALUES));
31       PetscCall(MatSetValues(A,1,&i,1,&asj[k],&asa[k],INSERT_VALUES));
32       if (i != asj[k]) { /* insert symmetric entry */
33         PetscCall(MatSetValues(A,1,&asj[k],1,&i,&asa[k],INSERT_VALUES));
34       }
35       k++;
36     }
37   }
38   PetscCall(MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY));
39   PetscCall(MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY));
40 
41   /* Create a baij matrix using MatCreateSeqBAIJWithArrays() */
42   PetscCall(MatGetRowIJ(A,0,PETSC_FALSE,PETSC_FALSE,&n,&ai,&aj,&flg));
43   PetscCall(MatSeqAIJGetArray(A,&aa));
44   /* WARNING: This sharing is dangerous if either A or B is later assembled */
45   PetscCall(MatCreateSeqBAIJWithArrays(PETSC_COMM_SELF,1,5,5,(PetscInt*)ai,(PetscInt*)aj,aa,&B));
46   PetscCall(MatSeqAIJRestoreArray(A,&aa));
47   PetscCall(MatRestoreRowIJ(A,0,PETSC_FALSE,PETSC_FALSE,&n,&ai,&aj,&flg));
48   PetscCall(MatMultEqual(A,B,10,&flg));
49   PetscCheck(flg,PETSC_COMM_SELF,PETSC_ERR_ARG_NOTSAMETYPE,"MatMult(A,B) are NOT equal");
50 
51   /* Create a sbaij matrix using MatCreateSeqSBAIJWithArrays() */
52   PetscCall(MatCreateSeqSBAIJWithArrays(PETSC_COMM_SELF,1,5,5,asi,asj,asa,&As));
53   PetscCall(MatMultEqual(A,As,10,&flg));
54   PetscCheck(flg,PETSC_COMM_SELF,PETSC_ERR_ARG_NOTSAMETYPE,"MatMult(A,As) are NOT equal");
55 
56   /* Free spaces */
57   PetscCall(PetscRandomDestroy(&rctx));
58   PetscCall(MatDestroy(&A));
59   PetscCall(MatDestroy(&B));
60   PetscCall(MatDestroy(&As));
61   PetscCall(PetscFinalize());
62   return 0;
63 }
64