1c4762a1bSJed Brown 2c4762a1bSJed Brown static char help[] = "Reads in a binary file, extracts a submatrix from it, and writes to another binary file.\n\ 3c4762a1bSJed Brown Options:\n\ 4c4762a1bSJed Brown -fin <mat> : input matrix file\n\ 5c4762a1bSJed Brown -fout <mat> : output marrix file\n\ 6c4762a1bSJed Brown -start <row> : the row from where the submat should be extracted\n\ 7c4762a1bSJed Brown -m <sx> : the size of the submatrix\n"; 8c4762a1bSJed Brown 9c4762a1bSJed Brown #include <petscmat.h> 10c4762a1bSJed Brown #include <petscvec.h> 11c4762a1bSJed Brown 12*d71ae5a4SJacob Faibussowitsch int main(int argc, char **args) 13*d71ae5a4SJacob Faibussowitsch { 14c4762a1bSJed Brown char fin[PETSC_MAX_PATH_LEN], fout[PETSC_MAX_PATH_LEN] = "default.mat"; 15c4762a1bSJed Brown PetscViewer fdin, fdout; 16c4762a1bSJed Brown Vec b; 17c4762a1bSJed Brown MatType mtype = MATSEQBAIJ; 18c4762a1bSJed Brown Mat A, *B; 19c4762a1bSJed Brown PetscInt start = 0; 20c4762a1bSJed Brown PetscInt m; 21c4762a1bSJed Brown IS isrow, iscol; 22c4762a1bSJed Brown PetscBool flg; 23c4762a1bSJed Brown 24327415f7SBarry Smith PetscFunctionBeginUser; 259566063dSJacob Faibussowitsch PetscCall(PetscInitialize(&argc, &args, (char *)0, help)); 269566063dSJacob Faibussowitsch PetscCall(PetscOptionsGetString(NULL, NULL, "-fin", fin, sizeof(fin), &flg)); 2728b400f6SJacob Faibussowitsch PetscCheck(flg, PETSC_COMM_WORLD, PETSC_ERR_USER, "Must indicate binary file with the -fin option"); 289566063dSJacob Faibussowitsch PetscCall(PetscViewerBinaryOpen(PETSC_COMM_SELF, fin, FILE_MODE_READ, &fdin)); 29c4762a1bSJed Brown 309566063dSJacob Faibussowitsch PetscCall(PetscOptionsGetString(NULL, NULL, "-fout", fout, sizeof(fout), &flg)); 319566063dSJacob Faibussowitsch if (!flg) PetscCall(PetscPrintf(PETSC_COMM_WORLD, "Writing submatrix to file : %s\n", fout)); 329566063dSJacob Faibussowitsch PetscCall(PetscViewerBinaryOpen(PETSC_COMM_SELF, fout, FILE_MODE_WRITE, &fdout)); 33c4762a1bSJed Brown 349566063dSJacob Faibussowitsch PetscCall(MatCreate(PETSC_COMM_SELF, &A)); 359566063dSJacob Faibussowitsch PetscCall(MatSetType(A, mtype)); 369566063dSJacob Faibussowitsch PetscCall(MatLoad(A, fdin)); 379566063dSJacob Faibussowitsch PetscCall(PetscViewerDestroy(&fdin)); 38c4762a1bSJed Brown 399566063dSJacob Faibussowitsch PetscCall(MatGetSize(A, &m, &m)); 40c4762a1bSJed Brown m /= 2; 419566063dSJacob Faibussowitsch PetscCall(PetscOptionsGetInt(NULL, NULL, "-start", &start, NULL)); 429566063dSJacob Faibussowitsch PetscCall(PetscOptionsGetInt(NULL, NULL, "-m", &m, NULL)); 43c4762a1bSJed Brown 449566063dSJacob Faibussowitsch PetscCall(ISCreateStride(PETSC_COMM_SELF, m, start, 1, &isrow)); 459566063dSJacob Faibussowitsch PetscCall(ISCreateStride(PETSC_COMM_SELF, m, start, 1, &iscol)); 469566063dSJacob Faibussowitsch PetscCall(MatCreateSubMatrices(A, 1, &isrow, &iscol, MAT_INITIAL_MATRIX, &B)); 479566063dSJacob Faibussowitsch PetscCall(MatView(B[0], fdout)); 48c4762a1bSJed Brown 499566063dSJacob Faibussowitsch PetscCall(VecCreate(PETSC_COMM_SELF, &b)); 509566063dSJacob Faibussowitsch PetscCall(VecSetSizes(b, PETSC_DECIDE, m)); 519566063dSJacob Faibussowitsch PetscCall(VecSetFromOptions(b)); 529566063dSJacob Faibussowitsch PetscCall(MatView(B[0], fdout)); 539566063dSJacob Faibussowitsch PetscCall(PetscViewerDestroy(&fdout)); 54c4762a1bSJed Brown 559566063dSJacob Faibussowitsch PetscCall(MatDestroy(&A)); 569566063dSJacob Faibussowitsch PetscCall(MatDestroy(&B[0])); 579566063dSJacob Faibussowitsch PetscCall(VecDestroy(&b)); 589566063dSJacob Faibussowitsch PetscCall(PetscFree(B)); 599566063dSJacob Faibussowitsch PetscCall(ISDestroy(&iscol)); 609566063dSJacob Faibussowitsch PetscCall(ISDestroy(&isrow)); 619566063dSJacob Faibussowitsch PetscCall(PetscFinalize()); 62b122ec5aSJacob Faibussowitsch return 0; 63c4762a1bSJed Brown } 64c4762a1bSJed Brown 65c4762a1bSJed Brown /*TEST 66c4762a1bSJed Brown 67c4762a1bSJed Brown test: 68c4762a1bSJed Brown args: -fin ${DATAFILESPATH}/matrices/small -fout joe -start 2 -m 4 69dfd57a17SPierre Jolivet requires: datafilespath double !complex !defined(PETSC_USE_64BIT_INDICES) 70c4762a1bSJed Brown 71c4762a1bSJed Brown TEST*/ 72