Projection between meshes

[dokken]

You need to allow for extrapolation if projections between meshes in legacy dolfin.

In dolfinx, ive sketched out how to do this in

L2 projection of fine mesh solution to a coarse mesh

At some point you have to evaulate the function at the quadrature points of the coarse grid when doing the projection. The following code illlustrates how to compute the L2 projection from a fine grid to a coarse grid by: Get values of the fine function at the quadrature points of the coarse grid. Then do the projection # Illustration of projection from one mesh to another # Author: Jørgen S. Dokken # SPDX License: MIT import ufl import dolfinx from mpi4py import MPI import basix.ufl import d…