On Tue, Jun 25, 2019 at 6:44 AM Ham, David A <david.ham@imperial.ac.uk> wrote:

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.


Ah. I named them the opposite way :) This is a good window into how my mind works. I thought
since the Jacobian maps reference to real (and phi for that matter) that the default direction of any
mapping should be ref-to-real. It seems like this is the overwhelming convention in large deformations.

  Thanks,

    Matt
 

 

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> wrote:

Dear Simone

On Tue, 25 Jun 2019 at 00:34, Simone Puel <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
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

 



--
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