petsc-3.7.5 2017-01-01
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MatPreallocateSet

 Indicates the locations (rows and columns) in the matrix where nonzeros will be inserted using a local number of the rows and columns

Synopsis

#include <petscmat.h>
PetscErrorCode MatPreallocateSet(PetscInt nrows, PetscInt *rows,PetscInt ncols, PetscInt *cols,PetscInt *dnz, PetscInt *onz)
Not Collective

Input Parameters

row - the row
ncols - the number of columns in the matrix
cols - the columns indicated

Output Parameters

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 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 variables declared in MatPreallocateInitialize().

See Also

MatPreallocateFinalize(), MatPreallocateSet(), MatPreallocateSymmetricSetBlock(), MatPreallocateInitialize(),
MatPreallocateInitialize(), MatPreallocateSetLocal()

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