xref: /petsc/src/mat/tests/ex43.c (revision 609caa7c8c030312b00807b4f015fd827bb80932)
1c4762a1bSJed Brown static char help[] = "Saves a dense matrix in a dense format (binary).\n\n";
2c4762a1bSJed Brown 
3c4762a1bSJed Brown #include <petscmat.h>
4c4762a1bSJed Brown 
main(int argc,char ** args)5d71ae5a4SJacob Faibussowitsch int main(int argc, char **args)
6d71ae5a4SJacob Faibussowitsch {
7c4762a1bSJed Brown   Mat         C;
8c4762a1bSJed Brown   PetscScalar v;
9c4762a1bSJed Brown   PetscInt    i, j, m = 4, n = 4;
10c4762a1bSJed Brown   PetscMPIInt rank, size;
11c4762a1bSJed Brown   PetscViewer viewer;
12c4762a1bSJed Brown 
13327415f7SBarry Smith   PetscFunctionBeginUser;
14c8025a54SPierre Jolivet   PetscCall(PetscInitialize(&argc, &args, NULL, help));
159566063dSJacob Faibussowitsch   PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
169566063dSJacob Faibussowitsch   PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size));
179566063dSJacob Faibussowitsch   PetscCall(PetscOptionsGetInt(NULL, NULL, "-m", &m, NULL));
189566063dSJacob Faibussowitsch   PetscCall(PetscOptionsGetInt(NULL, NULL, "-n", &n, NULL));
19c4762a1bSJed Brown 
20c4762a1bSJed Brown   /* PART 1:  Generate matrix, then write it in binary format */
21c4762a1bSJed Brown 
22c4762a1bSJed Brown   /* Generate matrix */
239566063dSJacob Faibussowitsch   PetscCall(MatCreateSeqDense(PETSC_COMM_WORLD, m, n, NULL, &C));
24c4762a1bSJed Brown   for (i = 0; i < m; i++) {
25c4762a1bSJed Brown     for (j = 0; j < n; j++) {
26c4762a1bSJed Brown       v = i * m + j;
279566063dSJacob Faibussowitsch       PetscCall(MatSetValues(C, 1, &i, 1, &j, &v, INSERT_VALUES));
28c4762a1bSJed Brown     }
29c4762a1bSJed Brown   }
309566063dSJacob Faibussowitsch   PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
319566063dSJacob Faibussowitsch   PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
329566063dSJacob Faibussowitsch   PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD, "matrix.dat", FILE_MODE_WRITE, &viewer));
339566063dSJacob Faibussowitsch   PetscCall(MatView(C, viewer));
349566063dSJacob Faibussowitsch   PetscCall(PetscViewerDestroy(&viewer));
359566063dSJacob Faibussowitsch   PetscCall(MatDestroy(&C));
369566063dSJacob Faibussowitsch   PetscCall(PetscFinalize());
37b122ec5aSJacob Faibussowitsch   return 0;
38c4762a1bSJed Brown }
39c4762a1bSJed Brown 
40c4762a1bSJed Brown /*TEST
41c4762a1bSJed Brown 
42c4762a1bSJed Brown    test:
43*3886731fSPierre Jolivet      output_file: output/empty.out
44c4762a1bSJed Brown 
45c4762a1bSJed Brown TEST*/
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