petsc-3.4.4 2014-03-13

MatMFFDSetType

Sets the method that is used to compute the differencing parameter for finite differene matrix-free formulations.

Synopsis

#include "petscmat.h"   
PetscErrorCode  MatMFFDSetType(Mat mat,MatMFFDType ftype)

Input Parameters

mat - the "matrix-free" matrix created via MatCreateSNESMF(), or MatCreateMFFD() or MatSetType(mat,MATMFFD);
ftype - the type requested, either MATMFFD_WP or MATMFFD_DS

Notes

For example, such routines can compute h for use in Jacobian-vector products of the form

F(x+ha) - F(x) F'(u)a ~= ---------------- h

See Also

MatCreateSNESMF(), MatMFFDRegister(), MatMFFDSetFunction()

Level:advanced
Location:
src/mat/impls/mffd/mffd.c
Index of all Mat routines
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Index of all manual pages