@pimms.value<EOL><INDENT>def face_coordinates(tess, coordinates):<DEDENT>
return pimms.imm_array([coordinates[:,f] for f in tess.indexed_faces])<EOL>
mesh.face_coordinates is the (3 x d x m) array of the coordinates that define each face in
  the given mesh; d is the number of dimensions that define the vertex positions in the mesh
  and m is the number of triange faces in the mesh.