int main(int argc,char **args)
{
Mat A;
PetscErrorCode ierr;
PetscReal *norms;
char file[PETSC_MAX_PATH_LEN];
PetscBool flg;
PetscViewer fd;
PetscInt n;
PetscMPIInt rank;
PetscInitialize(&argc,&args,(char *)0,help);
ierr = MPI_Comm_rank(PETSC_COMM_WORLD,&rank);CHKERRQ(ierr);
ierr = PetscOptionsGetString(PETSC_NULL,"-f",file,PETSC_MAX_PATH_LEN,&flg);CHKERRQ(ierr);
if (!flg) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_USER,"Must indicate binary file with the -f option");
ierr = PetscViewerBinaryOpen(PETSC_COMM_WORLD,file,FILE_MODE_READ,&fd);CHKERRQ(ierr);
ierr = MatCreate(PETSC_COMM_WORLD,&A);CHKERRQ(ierr);
ierr = MatSetFromOptions(A);CHKERRQ(ierr);
ierr = MatLoad(A,fd);CHKERRQ(ierr);
ierr = PetscViewerDestroy(&fd);CHKERRQ(ierr);
ierr = MatGetSize(A,PETSC_NULL,&n);CHKERRQ(ierr);
ierr = PetscMalloc(n*sizeof(PetscReal),&norms);CHKERRQ(ierr);
ierr = MatGetColumnNorms(A,NORM_2,norms);CHKERRQ(ierr);
if (!rank) {
ierr = PetscRealView(n,norms,PETSC_VIEWER_STDOUT_SELF);CHKERRQ(ierr);
}
ierr = PetscFree(norms);CHKERRQ(ierr);
ierr = MatDestroy(&A);CHKERRQ(ierr);
ierr = PetscFinalize();
return 0;
}
static PetscErrorCode getSumSquares(Mat matrix, double *diag) {
PetscErrorCode ierr;
int i, j;
double *sumr, *sumc;
PetscInt n, mLocal, nLocal, low, high;
PetscReal *aux;
PetscFunctionBegin;
ierr = MatGetSize(matrix, NULL, &n); CHKERRQ(ierr);
ierr = MatGetLocalSize(matrix, &mLocal, &nLocal); CHKERRQ(ierr);
sumr = diag; sumc = &diag[mLocal];
ierr = PetscMalloc1(n, &aux); CHKERRQ(ierr);
ierr = MatGetColumnNorms(matrix, NORM_2, aux); CHKERRQ(ierr);
ierr = MatGetOwnershipRangeColumn(matrix, &low, &high);CHKERRQ(ierr);
for (i=low; i<high; i++) {
sumc[i-low] = aux[i]*aux[i];
}
ierr = PetscFree(aux); CHKERRQ(ierr);
ierr = MatGetOwnershipRange(matrix, &low, &high); CHKERRQ(ierr);
for (i=low; i<high; i++) {
PetscInt ncols;
const PetscInt *cols;
const PetscScalar *vals;
sumr[i-low] = 0.0;
ierr = MatGetRow(matrix, i, &ncols, &cols, &vals); CHKERRQ(ierr);
for (j = 0; j < ncols; j++) {
sumr[i-low] += PetscRealPart(vals[j]*PetscConj(vals[j]));
}
ierr = MatRestoreRow(matrix, i, &ncols, &cols, &vals); CHKERRQ(ierr);
}
PetscFunctionReturn(0);
}