Dear Ed,


This had indeed been a Firedrake issue (and not DMPlex) as you pointed out, and
it was actually resolved in Firedrake when we merged  https://github.com/firedrakeproject/firedrake/pull/1474 .
So I think if you update your Firedrake ('Upgrade' section of https://www.firedrakeproject.org/download.html# ), this error will go away.


Best,
Koki
From: firedrake-bounces@imperial.ac.uk <firedrake-bounces@imperial.ac.uk> on behalf of Ed Bueler <elbueler@alaska.edu>
Sent: Tuesday, December 17, 2019 7:46 PM
To: firedrake <firedrake@imperial.ac.uk>
Cc: Barry Smith <bsmith@mcs.anl.gov>; Matthew Knepley <knepley@rice.edu>
Subject: [firedrake] Firedrake/DMPlex parallel restriction: one d.o.f. per process
 
Firedrake devs --

This is substantially a matter of curiosity, but I figure I am missing something I should understand.

Namely, parallel runs will generate "RuntimeError: Mesh must have at least one cell on every process" if you attempt to have less.  My understanding is that this restriction is not intrinsic to PETSc DMPlex, though the restriction does apply to DMDA.  I know that Firedrake uses separate DMPlex for the mesh and for the data layout.  What is the basic story here?

Thanks,

Ed

--
Ed Bueler
Dept of Mathematics and Statistics
University of Alaska Fairbanks
Fairbanks, AK 99775-6660
306C Chapman