petsc-3.4.2 2013-07-02

# MatPreallocateLocation

An alternative to MatPreallocationSet() that puts the nonzero locations into the matrix if it exists

### Synopsis

    #include "petscmat.h"
    PetscErrorCode MatPreallocateLocations(Mat A,PetscInt row,PetscInt ncols,PetscInt *cols,PetscInt *dnz,PetscInt *onz)

Not Collective

### Input Parameters

A -matrix
row -row where values exist (must be local to this process)
ncols -number of columns
cols -columns with nonzeros
dnz -the array that will be passed to the matrix preallocation routines
ozn -the other array passed to the matrix preallocation routines

### Notes

See the <A href="../../docs/manual.pdf#nameddest=Chapter 11 Hints for Performance Tuning">Hints for Performance Improvment</A> chapter in the users manual for more details.

Do not malloc or free dnz and onz that is handled internally by these routines

This is a MACRO not a function because it uses a bunch of variables private to the MatPreallocation.... routines.

### See Also

MatPreallocateInitialize(), MatPreallocateSet(), MatPreallocateSymmetricSet(), MatPreallocateSetLocal(),
MatPreallocateSymmetricSetLocal()

Level:intermediate
Location: src/mat/../../include/petscmat.h
Index of all Mat routines
Table of Contents for all manual pages
Index of all manual pages