MatSetValuesLocal#

Inserts or adds values into certain locations of a matrix, using a local numbering of the rows and columns.

Synopsis#

#include "petscmat.h" 
PetscErrorCode MatSetValuesLocal(Mat mat, PetscInt nrow, const PetscInt irow[], PetscInt ncol, const PetscInt icol[], const PetscScalar y[], InsertMode addv)

Not Collective

Input Parameters#

mat - the matrix
nrow - number of rows
irow - the row local indices
ncol - number of columns
icol - the column local indices
y - a logically two-dimensional array of values
addv - either INSERT_VALUES to add values to any existing entries, or INSERT_VALUES to replace existing entries with new values

Notes#

If you create the matrix yourself (that is not with a call to DMCreateMatrix()) then you MUST call MatSetLocalToGlobalMapping() before using this routine

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

These values may be cached, so MatAssemblyBegin() and MatAssemblyEnd() MUST be called after all calls to MatSetValuesLocal() have been completed.

Fortran Notes#

If any of irow, icol, and y are scalars pass them using, for example,

  MatSetValuesLocal(mat, one, [irow], one, [icol], [y], INSERT_VALUES)

If y is a two-dimensional array use reshape() to pass it as a one dimensional array

Developer Note#

This is labeled with C so does not automatically generate Fortran stubs and interfaces because it requires multiple Fortran interfaces depending on which arguments are scalar or arrays.