petsc-3.9.4 2018-09-11
MatPreallocateLocation
An alternative to MatPreallocateSet() 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
onz -the other array passed to the matrix preallocation routines
Notes
See Users-Manual: Chapter 14 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