petsc-3.12.5 2020-03-29
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
|
| 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 variables declared in MatPreallocateInitialize().
See Also
MatPreallocateFinalize(), MatPreallocateSet(), MatPreallocateSymmetricSetBlock()
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