1c1fff1c6SRichard Tran Mills static char help[] = "Tests MATCENTERING matrix type.\n\n"; 2c1fff1c6SRichard Tran Mills 3c1fff1c6SRichard Tran Mills #include <petscmat.h> 4c1fff1c6SRichard Tran Mills 5d71ae5a4SJacob Faibussowitsch int main(int argc, char **argv) 6d71ae5a4SJacob Faibussowitsch { 7c1fff1c6SRichard Tran Mills PetscInt n; 8c1fff1c6SRichard Tran Mills Mat C; 9c1fff1c6SRichard Tran Mills Vec x, y; 10c1fff1c6SRichard Tran Mills PetscReal norm; 11c1fff1c6SRichard Tran Mills PetscMPIInt size; 12c1fff1c6SRichard Tran Mills 13327415f7SBarry Smith PetscFunctionBeginUser; 14*c8025a54SPierre Jolivet PetscCall(PetscInitialize(&argc, &argv, NULL, help)); 159566063dSJacob Faibussowitsch PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size)); 16c1fff1c6SRichard Tran Mills 17c1fff1c6SRichard Tran Mills /* Create a parallel vector with 10*size total entries, and fill it with 1s. */ 18c1fff1c6SRichard Tran Mills n = 10 * size; 199566063dSJacob Faibussowitsch PetscCall(VecCreate(PETSC_COMM_WORLD, &x)); 209566063dSJacob Faibussowitsch PetscCall(VecSetSizes(x, PETSC_DECIDE, n)); 219566063dSJacob Faibussowitsch PetscCall(VecSetFromOptions(x)); 229566063dSJacob Faibussowitsch PetscCall(VecSet(x, 1.0)); 23c1fff1c6SRichard Tran Mills 24c1fff1c6SRichard Tran Mills /* Create a corresponding n x n centering matrix and use it to create a mean-centered y = C * x. */ 259566063dSJacob Faibussowitsch PetscCall(VecDuplicate(x, &y)); 269566063dSJacob Faibussowitsch PetscCall(MatCreateCentering(PETSC_COMM_WORLD, PETSC_DECIDE, n, &C)); 279566063dSJacob Faibussowitsch PetscCall(MatMult(C, x, y)); 28c1fff1c6SRichard Tran Mills 29c1fff1c6SRichard Tran Mills /* Verify that the centered vector y has norm 0. */ 309566063dSJacob Faibussowitsch PetscCall(VecNorm(y, NORM_2, &norm)); 319566063dSJacob Faibussowitsch PetscCall(PetscPrintf(PETSC_COMM_WORLD, "Vector norm after MatMult() with centering matrix applied to vector of ones is %f.\n", (double)norm)); 32c1fff1c6SRichard Tran Mills 33c1fff1c6SRichard Tran Mills /* Now repeat, but using MatMultTranspose(). */ 349566063dSJacob Faibussowitsch PetscCall(MatMultTranspose(C, x, y)); 359566063dSJacob Faibussowitsch PetscCall(VecNorm(y, NORM_2, &norm)); 369566063dSJacob Faibussowitsch PetscCall(PetscPrintf(PETSC_COMM_WORLD, "Vector norm after MatMultTranspose() with centering matrix applied to vector of ones is %f.\n", (double)norm)); 37c1fff1c6SRichard Tran Mills 38c1fff1c6SRichard Tran Mills /* Clean up. */ 399566063dSJacob Faibussowitsch PetscCall(VecDestroy(&x)); 409566063dSJacob Faibussowitsch PetscCall(VecDestroy(&y)); 419566063dSJacob Faibussowitsch PetscCall(MatDestroy(&C)); 429566063dSJacob Faibussowitsch PetscCall(PetscFinalize()); 43b122ec5aSJacob Faibussowitsch return 0; 44c1fff1c6SRichard Tran Mills } 45c1fff1c6SRichard Tran Mills 46c1fff1c6SRichard Tran Mills /*TEST 47c1fff1c6SRichard Tran Mills 48c1fff1c6SRichard Tran Mills test: 49c1fff1c6SRichard Tran Mills suffix: 1 50c1fff1c6SRichard Tran Mills nsize: 1 51c1fff1c6SRichard Tran Mills output_file: output/ex247.out 52c1fff1c6SRichard Tran Mills 53c1fff1c6SRichard Tran Mills test: 54c1fff1c6SRichard Tran Mills suffix: 2 55c1fff1c6SRichard Tran Mills nsize: 2 56c1fff1c6SRichard Tran Mills output_file: output/ex247.out 57c1fff1c6SRichard Tran Mills 58c1fff1c6SRichard Tran Mills TEST*/ 59