xref: /petsc/src/mat/tests/ex49.c (revision 732aec7a18f2199fb53bb9a2f3aef439a834ce31)

static char help[] = "Tests MatTranspose(), MatNorm(), and MatAXPY().\n\n";

#include <petscmat.h>

int main(int argc, char **argv)
{
  Mat         mat, tmat = 0;
  PetscInt    m = 4, n, i, j;
  PetscMPIInt size, rank;
  PetscInt    rstart, rend, rect = 0;
  PetscBool   flg;
  PetscScalar v;
  PetscReal   normf, normi, norm1;
  MatInfo     info;

  PetscFunctionBeginUser;
  PetscCall(PetscInitialize(&argc, &argv, NULL, help));
  PetscCall(PetscOptionsGetInt(NULL, NULL, "-m", &m, NULL));
  PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
  PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size));
  n = m;
  PetscCall(PetscOptionsHasName(NULL, NULL, "-rect1", &flg));
  if (flg) {
    n += 2;
    rect = 1;
  }
  PetscCall(PetscOptionsHasName(NULL, NULL, "-rect2", &flg));
  if (flg) {
    n -= 2;
    rect = 1;
  }

  /* Create and assemble matrix */
  PetscCall(MatCreate(PETSC_COMM_WORLD, &mat));
  PetscCall(MatSetSizes(mat, PETSC_DECIDE, PETSC_DECIDE, m, n));
  PetscCall(MatSetFromOptions(mat));
  PetscCall(MatSetUp(mat));
  PetscCall(MatGetOwnershipRange(mat, &rstart, &rend));
  for (i = rstart; i < rend; i++) {
    for (j = 0; j < n; j++) {
      v = 10 * i + j;
      PetscCall(MatSetValues(mat, 1, &i, 1, &j, &v, INSERT_VALUES));
    }
  }
  PetscCall(MatAssemblyBegin(mat, MAT_FINAL_ASSEMBLY));
  PetscCall(MatAssemblyEnd(mat, MAT_FINAL_ASSEMBLY));

  /* Print info about original matrix */
  PetscCall(MatGetInfo(mat, MAT_GLOBAL_SUM, &info));
  PetscCall(PetscPrintf(PETSC_COMM_WORLD, "original matrix nonzeros = %" PetscInt_FMT ", allocated nonzeros = %" PetscInt_FMT "\n", (PetscInt)info.nz_used, (PetscInt)info.nz_allocated));
  PetscCall(MatNorm(mat, NORM_FROBENIUS, &normf));
  PetscCall(MatNorm(mat, NORM_1, &norm1));
  PetscCall(MatNorm(mat, NORM_INFINITY, &normi));
  PetscCall(PetscPrintf(PETSC_COMM_WORLD, "original: Frobenius norm = %g, one norm = %g, infinity norm = %g\n", (double)normf, (double)norm1, (double)normi));
  PetscCall(MatView(mat, PETSC_VIEWER_STDOUT_WORLD));

  /* Form matrix transpose */
  PetscCall(PetscOptionsHasName(NULL, NULL, "-in_place", &flg));
  if (flg) {
    PetscCall(MatTranspose(mat, MAT_INPLACE_MATRIX, &mat)); /* in-place transpose */
    tmat = mat;
    mat  = 0;
  } else { /* out-of-place transpose */
    PetscCall(MatTranspose(mat, MAT_INITIAL_MATRIX, &tmat));
  }

  /* Print info about transpose matrix */
  PetscCall(MatGetInfo(tmat, MAT_GLOBAL_SUM, &info));
  PetscCall(PetscPrintf(PETSC_COMM_WORLD, "transpose matrix nonzeros = %" PetscInt_FMT ", allocated nonzeros = %" PetscInt_FMT "\n", (PetscInt)info.nz_used, (PetscInt)info.nz_allocated));
  PetscCall(MatNorm(tmat, NORM_FROBENIUS, &normf));
  PetscCall(MatNorm(tmat, NORM_1, &norm1));
  PetscCall(MatNorm(tmat, NORM_INFINITY, &normi));
  PetscCall(PetscPrintf(PETSC_COMM_WORLD, "transpose: Frobenius norm = %g, one norm = %g, infinity norm = %g\n", (double)normf, (double)norm1, (double)normi));
  PetscCall(MatView(tmat, PETSC_VIEWER_STDOUT_WORLD));

  /* Test MatAXPY */
  if (mat && !rect) {
    PetscScalar alpha = 1.0;
    PetscCall(PetscOptionsGetScalar(NULL, NULL, "-alpha", &alpha, NULL));
    PetscCall(PetscPrintf(PETSC_COMM_WORLD, "matrix addition:  B = B + alpha * A\n"));
    PetscCall(MatAXPY(tmat, alpha, mat, DIFFERENT_NONZERO_PATTERN));
    PetscCall(MatView(tmat, PETSC_VIEWER_STDOUT_WORLD));
  }

  /* Free data structures */
  PetscCall(MatDestroy(&tmat));
  if (mat) PetscCall(MatDestroy(&mat));

  PetscCall(PetscFinalize());
  return 0;
}

/*TEST

   test:

   testset:
     args: -rect1
     test:
       suffix: r1
       output_file: output/ex49_r1.out
     test:
       suffix: r1_inplace
       args: -in_place
       output_file: output/ex49_r1.out
     test:
       suffix: r1_par
       nsize: 2
       output_file: output/ex49_r1_par.out
     test:
       suffix: r1_par_inplace
       args: -in_place
       nsize: 2
       output_file: output/ex49_r1_par.out

TEST*/