Simple question about writing to files

[puhl]

Hi all,
I have a simple question about exporting a mesh and corresponding function values. I can write the mesh values to a file using mesh.coordinates() and the function values using u.vector(), but I don’t know how to match the function points with the right coordinates for some post-processing elsewhere. How can I do this? (Yes, this is a very basic question, thanks in advance)

[dokken]

You should either use:
FunctionSpace.tabulate_dof_coordinates() which has a one to one correspondence with

@puhl

lues. I can write the mesh values to a file using mesh.coordinates() and the function values using u.vector()

Or you can interpolate the function values into the mesh coordinate space by using
compute_vertex_values() as shown in

Save the result of mpirun in a numpy array

Here is a simple example that gathers the data on the first process: from dolfin import * import numpy as np mesh = UnitSquareMesh(2, 2) V = FunctionSpace(mesh, "CG", 1) u = project(Expression("x[0]", degree=1), V) vertex_values = u.compute_vertex_values() coordinates = mesh.coordinates() from mpi4py import MPI gathered_coordinates = MPI.COMM_WORLD.gather(coordinates, root=0) gathered_values = MPI.COMM_WORLD.gather(vertex_values, root=0) global_indices = MPI.COMM_WORLD.gather(mesh.topology().g…