Actual source code: ex171.c


  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;
 10:   PetscViewer    fd;              /* viewer */
 11:   char           file[PETSC_MAX_PATH_LEN]; /* input file name */
 12:   PetscReal      norm;
 13:   PetscBool      flg;

 15:   PetscInitialize(&argc,&args,(char*)0,help);
 16:   /* Determine file from which we read the matrix A */
 17:   PetscOptionsGetString(NULL,NULL,"-f",file,sizeof(file),&flg);

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

 33:   /* Free data structures */
 34:   MatDestroy(&A);
 35:   VecDestroy(&x);
 36:   PetscFinalize();
 37:   return 0;
 38: }

 40: /*TEST

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

 47: TEST*/