2: static char help[] = "Tests MatDiagonalSet() on MatLoad() matrix \n\n";

  4: #include <petscmat.h>

  6: int main(int argc,char **args)
  7: {
  8:   Mat            A;
  9:   Vec            x;
 11:   PetscViewer    fd;              /* viewer */
 12:   char           file[PETSC_MAX_PATH_LEN]; /* input file name */
 13:   PetscReal      norm;
 14:   PetscBool      flg;

 16:   PetscInitialize(&argc,&args,(char*)0,help);if (ierr) return ierr;
 17:   /* Determine file from which we read the matrix A */
 18:   PetscOptionsGetString(NULL,NULL,"-f",file,sizeof(file),&flg);
 19:   if (!flg) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_USER,"Must indicate binary file with the -f option");

 21:   /* Load matrix A */
 22:   PetscViewerBinaryOpen(PETSC_COMM_WORLD,file,FILE_MODE_READ,&fd);
 23:   MatCreate(PETSC_COMM_WORLD,&A);
 24:   MatLoad(A,fd);
 25:   PetscViewerDestroy(&fd);
 26:   MatCreateVecs(A,&x,NULL);
 27:   MatGetDiagonal(A,x);
 28:   VecScale(x,-1.0);
 29:   MatDiagonalSet(A,x,ADD_VALUES);
 30:   MatGetDiagonal(A,x);
 31:   VecNorm(x,NORM_2,&norm);
 32:   PetscPrintf(PETSC_COMM_WORLD,"Norm %g\n",(double)norm);

 34:   /* Free data structures */
 35:   MatDestroy(&A);
 36:   VecDestroy(&x);
 37:   PetscFinalize();
 38:   return ierr;
 39: }


 42: /*TEST

 44:    test:
 45:       nsize: 4
 46:       requires: datafilespath !complex double !define(PETSC_USE_64BIT_INDICES)
 47:       args: -f ${wPETSC_DIR}/share/petsc/datafiles/matrices/ns-real-int32-float64 -malloc_dump

 49: TEST*/