petsc-3.3-p7 2013-05-11


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


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


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(),

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