petsc-3.6.1 2015-08-06

SNESFASSetInterpolation

Sets the function to be used to calculate the interpolation from l-1 to the lth level

#include "petscsnes.h"  
PetscErrorCode SNESFASSetInterpolation(SNES snes, PetscInt level, Mat mat)

	snes	- the multigrid context
	mat	- the interpolation operator
	level	- the level (0 is coarsest) to supply [do not supply 0]

Usually this is the same matrix used also to set the restriction for the same level.

One can pass in the interpolation matrix or its transpose; PETSc figures out from the matrix size which one it is.

FAS, multigrid, set, interpolate, level