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# 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. Pass `NULL` to set all zeroes.

- 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.

## Fortran Note

If any of `ix` and `y` are scalars pass them using, for example,

      call VecSetValuesBlocked(mat, one, [ix], [y], INSERT_VALUES, ierr)

## See Also

Vectors and Parallel Data, `Vec`, `VecAssemblyBegin()`, `VecAssemblyEnd()`, `VecSetValuesBlockedLocal()`, `VecSetValues()`

## Level

intermediate

## Location

src/vec/vec/interface/rvector.c

## Examples

src/ksp/ksp/tutorials/ex56.c

## Implementations

VecSetValuesBlocked_MPI() in src/vec/vec/impls/mpi/pdvec.c
VecSetValuesBlocked_Seq() in src/vec/vec/impls/seq/bvec2.c

Index of all Vec routines
Table of Contents for all manual pages
Index of all manual pages