VecSetValuesBlocked#

Inserts or adds blocks of values into certain locations of a vector.

Synopsis#

#include "petscvec.h"   
PetscErrorCode VecSetValuesBlocked(Vec x, PetscInt ni, const PetscInt ix[], const PetscScalar y[], InsertMode iora)

Not Collective

Input Parameters#

x - vector to insert in
ni - number of blocks to add
ix - indices where to add in block count, rather than element count
y - array of values
iora - either INSERT_VALUES replaces existing entries with new values, ADD_VALUES, adds values to any existing entries

Notes#

VecSetValuesBlocked() sets x[bsix[i]+j] = y[bsi+j], for j=0,…,bs-1, for i=0,…,ni-1. where bs was set with VecSetBlockSize().

Calls to VecSetValuesBlocked() with the INSERT_VALUES and ADD_VALUES options cannot be mixed without intervening calls to the assembly routines.

These values may be cached, so VecAssemblyBegin() and VecAssemblyEnd() MUST be called after all calls to VecSetValuesBlocked() have been completed.

VecSetValuesBlocked() uses 0-based indices in Fortran as well as in C.

Negative indices may be passed in ix, these rows are simply ignored. This allows easily inserting element load matrices with homogeneous Dirichlet boundary conditions that you don’t want represented in the vector.