# MatSetValuesBlockedLocal

Inserts or adds values into certain locations of a matrix, using a local ordering of the nodes a block at a time.

### Synopsis

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

Not Collective

### Input Parameters

| x | - the matrix
| nrow, irow | - number of rows and their local indices
| ncol, icol | - number of columns and their local indices
| y | - a logically two-dimensional array of values
| addv | - either INSERT_VALUES or ADD_VALUES, where ADD_VALUES adds values to any existing entries, and INSERT_VALUES replaces existing entries with new values

### Notes

Before calling MatSetValuesBlockedLocal(), the user must first set the local-to-global mapping by calling MatSetLocalToGlobalMappingBlock(), where the mapping MUST be set for matrix blocks, not for matrix elements.

Calls to MatSetValuesBlockedLocal() 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 MatSetValuesBlockedLocal() have been completed.

### See Also

MatAssemblyBegin(), MatAssemblyEnd(), MatSetValuesLocal(), MatSetLocalToGlobalMappingBlock(), MatSetValuesBlocked()

Level:intermediate
Location:src/mat/interface/matrix.c
Index of all Mat routines
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