PETSc version 3.17.5

DMDASetInterpolationType

Sets the type of interpolation that will be returned by DMCreateInterpolation()

#include "petscdmda.h"   
PetscErrorCode  DMDASetInterpolationType(DM da,DMDAInterpolationType ctype)

Logically Collective on da

	da	- initial distributed array
	ctype	- DMDA_Q1 and DMDA_Q0 are currently the only supported forms

you should call this on the coarser of the two DMDAs you pass to DMCreateInterpolation()

intermediate