petsc-dev 2014-07-25
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MatPreallocateLocation

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

Synopsis

#include 
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 Users-Manual: Chapter 13 Hints for Performance Tuning 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(), MatPreallocateSymmetricSetBlock(), MatPreallocateSetLocal(),
MatPreallocateSymmetricSetLocalBlock()

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