MatCreate

Creates a matrix where the type is determined from either a call to MatSetType() or from the options database with a call to MatSetFromOptions(). The default matrix type is AIJ, using the routines MatCreateSeqAIJ() or MatCreateMPIAIJ() if you do not set a type in the options database. If you never call MatSetType() or MatSetFromOptions() it will generate an error when you try to use the matrix.

Synopsis

#include "petscmat.h"  
PetscErrorCode PETSCMAT_DLLEXPORT MatCreate(MPI_Comm comm,Mat *A)

Collective on MPI_Comm

Input Parameter

comm -MPI communicator

Output Parameter

A -the matrix

Options Database Keys

	-mat_type seqaij	- AIJ type, uses MatCreateSeqAIJ()
	-mat_type mpiaij	- AIJ type, uses MatCreateMPIAIJ()
	-mat_type seqbdiag	- block diagonal type, uses MatCreateSeqBDiag()
	-mat_type mpibdiag	- block diagonal type, uses MatCreateMPIBDiag()
	-mat_type mpirowbs	- rowbs type, uses MatCreateMPIRowbs()
	-mat_type seqdense	- dense type, uses MatCreateSeqDense()
	-mat_type mpidense	- dense type, uses MatCreateMPIDense()
	-mat_type seqbaij	- block AIJ type, uses MatCreateSeqBAIJ()
	-mat_type mpibaij	- block AIJ type, uses MatCreateMPIBAIJ()

Even More Options Database Keys

See the manpages for particular formats (e.g., MatCreateSeqAIJ()) for additional format-specific options.

C++ variants

	Mat MatCreate()		->		MatCreate(PETSC_COMM_WORLD,&A); return A;
	Mat MatCreate(MPI_Comm comm)		->		MatCreate(comm,&A); return A;

Notes

User manual sections

Keywords

matrix, create

Examples

src/mat/examples/tutorials/ex2.c.html
src/mat/examples/tutorials/ex5.c.html
src/ksp/ksp/examples/tutorials/ex1.c.html
src/ksp/ksp/examples/tutorials/ex2.c.html
src/ksp/ksp/examples/tutorials/ex3.c.html
src/ksp/ksp/examples/tutorials/ex4.c.html
src/ksp/ksp/examples/tutorials/ex5.c.html
src/ksp/ksp/examples/tutorials/ex7.c.html
src/ksp/ksp/examples/tutorials/ex8.c.html
src/ksp/ksp/examples/tutorials/ex9.c.html
src/ksp/ksp/examples/tutorials/ex11.c.html

Section 3.1 Creating and Assembling Matrices

- - Chapter 3 Matrices