MatPreallocateLocation

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

Synopsis

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 chapter in the users manual on performance 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(),
MatPreallocateSymmetricInitialize(), 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