I *think* that the concept is that the physical cell is mapped to the reference cell, so you are pulling back reference values through that mapping to get physical values. From: <firedrake-bounces@imperial.ac.uk> on behalf of Matthew Knepley <knepley@gmail.com> Date: Tuesday, 25 June 2019 at 11:37 To: Lawrence Mitchell <wence@gmx.li> Cc: firedrake <firedrake@imperial.ac.uk> Subject: Re: [firedrake] Error to run a script converted from FEniCS On Tue, Jun 25, 2019 at 4:52 AM Lawrence Mitchell <wence@gmx.li<mailto:wence@gmx.li>> wrote: Dear Simone On Tue, 25 Jun 2019 at 00:34, Simone Puel <spuel@utexas.edu<mailto:spuel@utexas.edu>> wrote:
Hi all,
My name is Simone Puel, a graduate student at the University of Texas at Austin. I think I have installed Firedrake correctly since I can run the example in the online tutorial. Thank you so much. I am trying to convert a script I made in FEniCS in Firedrake. I modified some syntax, but I have the following error:
[...]
assert len(gsh) == 1 AssertionError
I made a very simple mesh in Gmsh (attached) and the script is the linear elasticity using a mixed formulation (Arnold et al., 2007). The problem is a 2D rectangle with a vertical fault where I prescribe 1 m of slip. I attached the mesh (.msh file) and the script. If anyone is able to help, I would appreciate it. Thank you so much in advance. Have a wonderful day!
This is, I think, I missing feature in the way UFL applies pullback to certain elements. (I'm slightly surprised the fenics version works!). This is my chance to ask a notational question. I recently put this in PETSc so I could see how everything worked, and it looks like the operation here is to put tabulated reference values of the basis or test functions into real space for a cell integral say. Isn't that operation the pushforward (adjoint of pullback). I use the pullback when I am mapping back user function evals to evaluate the action of dual basis vectors. Am I misunderstanding the terminology? Thanks, Matt In any case, I think I have a fix. Can you try with these changes in UFL: https://github.com/firedrakeproject/ufl/pull/18 And in Firedrake: https://github.com/firedrakeproject/firedrake/pull/1466 Thanks, Lawrence _______________________________________________ firedrake mailing list firedrake@imperial.ac.uk<mailto:firedrake@imperial.ac.uk> https://mailman.ic.ac.uk/mailman/listinfo/firedrake -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener https://www.cse.buffalo.edu/~knepley/<http://www.cse.buffalo.edu/~knepley/>