Actual source code: ex140.c
petsc-3.4.2 2013-07-02

      2: static char help[] = "Tests MatLoad(), MatZeroRowsColumns(), MatView() for MPIBAIJ.\n\n";

      4: #include <petscmat.h>

      8: int main(int argc,char **args)
      9: {
     10:   Mat            A;
     12:   char           file[PETSC_MAX_PATH_LEN];
     13:   PetscBool      aij,sbaij,flg;
     14:   PetscViewer    fd;
     15:   MatType        type = MATBAIJ;
     16:   PetscInt       n1   = 7, idx1[] = {1,5,6,8,9,12,15};
     17:   PetscInt       n2   = 5, idx2[] = {7,22,30,13,19};
     18:   Vec            b,x;
     19:   IS             is;
     20:   PetscInt       i;
     21:   PetscMPIInt    rank;

     23:   PetscInitialize(&argc,&args,(char*)0,help);
     24:   MPI_Comm_size(PETSC_COMM_WORLD,&rank);
     25:   PetscOptionsHasName(NULL,"-aij",&aij);
     26:   if (aij) type = MATAIJ;
     27:   PetscOptionsHasName(NULL,"-sbaij",&sbaij);
     28:   if (sbaij) type = MATSBAIJ;

     30:   PetscOptionsGetString(NULL,"-f",file,PETSC_MAX_PATH_LEN,&flg);
     31:   if (!flg) SETERRQ(PETSC_COMM_WORLD,1,"Must indicate binary file with the -f option");

     33:   /*
     34:      Open binary file.  Note that we use FILE_MODE_READ to indicate
     35:      reading from this file.
     36:   */
     37:   PetscViewerBinaryOpen(PETSC_COMM_WORLD,file,FILE_MODE_READ,&fd);

     39:   /*
     40:      Load the matrix; then destroy the viewer.
     41:   */
     42:   MatCreate(PETSC_COMM_WORLD,&A);
     43:   MatSetType(A,type);
     44:   MatLoad(A,fd);
     45:   VecCreate(PETSC_COMM_WORLD,&b);
     46:   VecLoad(b,fd);
     47:   PetscViewerDestroy(&fd);

     49:   /* save original matrix and vector for testing with MATLAB */
     50:   VecView(b,PETSC_VIEWER_BINARY_WORLD);
     51:   MatView(A,PETSC_VIEWER_BINARY_WORLD);

     53:   if (!rank) {
     54:     ISCreateGeneral(PETSC_COMM_WORLD,n1,idx1,PETSC_COPY_VALUES,&is);
     55:   } else {
     56:     ISCreateGeneral(PETSC_COMM_WORLD,n2,idx2,PETSC_COPY_VALUES,&is);
     57:   }
     58:   VecDuplicate(b,&x);
     59:   VecSet(x,0.0);
     60:   if (!rank) {
     61:     for (i=0; i<n1; i++) {
     62:       VecSetValue(x,idx1[i],1.0,INSERT_VALUES);
     63:     }
     64:   } else {
     65:     for (i=0; i<n2; i++) {
     66:       VecSetValue(x,idx2[i],1.0,INSERT_VALUES);
     67:     }
     68:   }
     69:   VecAssemblyBegin(x);
     70:   VecAssemblyEnd(x);
     71:   VecView(x,PETSC_VIEWER_BINARY_WORLD);

     73:   MatZeroRowsColumnsIS(A,is,2.0,x,b);
     74:   /*
     75:      Save the matrix and vector; then destroy the viewer.
     76:   */
     77:   ISView(is,PETSC_VIEWER_BINARY_WORLD);
     78:   VecView(b,PETSC_VIEWER_BINARY_WORLD);
     79:   MatView(A,PETSC_VIEWER_BINARY_WORLD);
     80:   VecDestroy(&x);
     81:   VecDestroy(&b);
     82:   ISDestroy(&is);
     83:   MatDestroy(&A);
     84:   PetscFinalize();
     85:   return 0;
     86: }