November 2020 - firedrake - imperial.ac.uk

Bitcoin £13,709.52
by BTC System 30 Nov '20

30 Nov '20

Best friends buy £300,000 plane for a once-in-a-life time trip around the world. You won’t believe how they paid for it! Best Friends Andy Coulgrass and Dominik Fincher have achieved their dreams of buying a plane to fly themselves around the world and it was easier than you might think. Click Here to see the platform in action

1 0

Problem updating firedrake
by Andrew Hicks 16 Nov '20

16 Nov '20

Dear Firedrakers, I'm having trouble updating Firedrake. The error I get is this: Running /home/andrewh/firedrake/firedrake/bin/firedrake-update Configuration saved to /home/andrewh/firedrake/firedrake/.configuration.json Updating the git repository for firedrake Traceback (most recent call last): File "/home/andrewh/firedrake/firedrake/bin/firedrake-update", line 1394, in <module> git_update("firedrake") File "/home/andrewh/firedrake/firedrake/bin/firedrake-update", line 670, in git_update check_call(["git", "pull", "--recurse-submodules"]) File "/home/andrewh/firedrake/firedrake/bin/firedrake-update", line 526, in check_call log.debug(subprocess.check_output(arguments, stderr=subprocess.STDOUT, env=os.environ).decode()) File "/usr/lib/python3.6/subprocess.py", line 356, in check_output **kwargs).stdout File "/usr/lib/python3.6/subprocess.py", line 438, in run output=stdout, stderr=stderr) subprocess.CalledProcessError: Command '['git', 'pull', '--recurse-submodules']' returned non-zero exit status 1. And then, when I try to rebuild firedrake-update, I get this error when I try 'git pull': error: cannot lock ref 'refs/remotes/origin/wence/test/petsc-debugging': 'refs/remotes/origin/wence/test' exists; cannot create 'refs/remotes/origin/wence/test/petsc-debugging' >From https://github.com/firedrakeproject/firedrake ! [new branch] wence/test/petsc-debugging -> origin/wence/test/petsc-debugging (unable to update local ref) Anyone know why this is happening? Because of this my Firedrake is outdated. Andrew Hicks

2 1

Interpolating with FacetNormal giving AssertionError
by Andrew Hicks 09 Nov '20

09 Nov '20

Dear Firedrakers, I've encountered an issue in my code where it won't allow me to interpolate anything containing a reference to a defined FacetNormal onto a Function. Here is a snippet of code where I purposefully tried to put the bare minimum required to get the error: H1 = VectorFunctionSpace(mesh,'CG',1,5) x0,x1,x2 = SpatialCoordinate(mesh) nu = FacetNormal(mesh) h = interpolate(as_vector([nu[0],0,0,0,0]),H1) If I try to run this, I get the following traceback: File "/home/andrewh/firedrake/firedrake/src/firedrake/firedrake/function.py", line 353, in interpolate return interpolation.interpolate(expression, self, subset=subset) File "/home/andrewh/firedrake/firedrake/src/firedrake/firedrake/interpolation.py", line 36, in interpolate return Interpolator(expr, V, subset=subset, access=access).interpolate() File "/home/andrewh/firedrake/firedrake/src/firedrake/firedrake/interpolation.py", line 58, in __init__ self.callable, arguments = make_interpolator(expr, V, subset, access) File "/home/andrewh/firedrake/firedrake/src/firedrake/firedrake/interpolation.py", line 163, in make_interpolator loops.extend(_interpolator(V, tensor, expr, subset, arguments, access)) File "</home/andrewh/firedrake/firedrake/lib/python3.6/site-packages/decorator.py:decorator-gen-22>", line 2, in _interpolator File "/home/andrewh/firedrake/firedrake/src/firedrake/firedrake/utils.py", line 64, in wrapper return f(*args, **kwargs) File "/home/andrewh/firedrake/firedrake/src/firedrake/firedrake/interpolation.py", line 214, in _interpolator ast, oriented, needs_cell_sizes, coefficients, _ = compile_ufl_kernel(expr, to_pts, coords, coffee=False) File "/home/andrewh/firedrake/firedrake/src/tsfc/tsfc/driver.py", line 338, in compile_expression_at_points ir, = fem.compile_ufl(expression, point_sum=False, **config) File "/home/andrewh/firedrake/firedrake/src/tsfc/tsfc/fem.py", line 645, in compile_ufl result = map_expr_dags(context.translator, expressions) File "/home/andrewh/firedrake/firedrake/src/ufl/ufl/corealg/map_dag.py", line 73, in map_expr_dags r = handlers[v._ufl_typecode_](v) File "/home/andrewh/firedrake/firedrake/src/tsfc/tsfc/ufl_utils.py", line 144, in _modified_terminal return self.modified_terminal(o) File "/home/andrewh/firedrake/firedrake/src/tsfc/tsfc/fem.py", line 303, in modified_terminal return translate(mt.terminal, mt, self.context) File "/usr/lib/python3.6/functools.py", line 807, in wrapper return dispatch(args[0].__class__)(*args, **kw) File "/home/andrewh/firedrake/firedrake/src/tsfc/tsfc/fem.py", line 379, in translate_reference_normal return ctx.entity_selector(callback, mt.restriction) File "/home/andrewh/firedrake/firedrake/src/tsfc/tsfc/fem.py", line 98, in entity_selector return callback(self.entity_ids[0]) File "/home/andrewh/firedrake/firedrake/src/tsfc/tsfc/fem.py", line 377, in callback n = ctx.fiat_cell.compute_reference_normal(ctx.integration_dim, facet_i) File "/home/andrewh/firedrake/firedrake/src/fiat/FIAT/reference_element.py", line 387, in compute_reference_normal assert facet_dim == self.get_spatial_dimension() - 1 AssertionError Anyone know what could be the problem here? Any help would be much appreciated. -AH

3 2

Hybridization and postprocessing in FEEC
by Cotter, Colin J 02 Nov '20

02 Nov '20

Dear Firedrakers, We are hosting Ari Stern (WUSTL) for a talk on Zoom about his work on hybridization of finite element exterior calculus, with Firedrake implementation. This talk is open to all members of the Firedrake community, and the title, abstract and Zoom link (thanks for hosting, Lawrence) is below. The talk is on Tuesday 3rd November, 3pm GMT. all the best --cjc === TITLE Hybridization and postprocessing in finite element exterior calculus ABSTRACT Finite element exterior calculus (FEEC) unifies several families of conforming finite element methods for Laplace-type problems, including the scalar and vector Poisson equations. This talk presents a framework for hybridization of FEEC, which recovers known hybrid methods for the scalar Poisson equation and gives new hybrid methods for the vector Poisson equation. We also generalize Stenberg postprocessing, proving new superconvergence estimates. Based on joint work with Gerard Awanou, Maurice Fabien, and Johnny Guzman (arXiv:2008.00149). === https://durhamuniversity.zoom.us/j/94677202864?pwd=NGFkZ2QyUkRBREU3NTlnUjhi… Join our Cloud HD Video Meeting<https://durhamuniversity.zoom.us/j/94677202864?pwd=NGFkZ2QyUkRBREU3NTlnUjhi…> Zoom is the leader in modern enterprise video communications, with an easy, reliable cloud platform for video and audio conferencing, chat, and webinars across mobile, desktop, and room systems. Zoom Rooms is the original software-based conference room solution used around the world in board, conference, huddle, and training rooms, as well as executive offices and classrooms. Founded in 2011, Zoom helps businesses and organizations bring their teams together in a frictionless environment to get more done. Zoom is a publicly traded company headquartered in San Jose, CA. durhamuniversity.zoom.us Meeting ID: 946 7720 2864 Passcode: 870478

2 1