Difference in using float or Function(FunctionSpace(mesh, "R", 0))?

[ddundo]

In the newly-added bubble shear demo, I noticed that we get different solutions if I set variables dt and theta to be floats, rather than Function(FunctionSpace(mesh, "R", 0)). That is, the uniform resolution results don't appear to change, but the adapted ones do (both classical and metric advection). Any idea why this is the case?

[jwallwork23]

Thanks for reporting this, @ddundo. Putting it for discussion at the next meeting.

[ddundo]

This commit bfed2c2 also changed the non-uniform solutions, where time t was changed from being a float to Function(R)

[ddundo]

Very interesting... Even logging affects adaptive results:

(firedrake) firedrake@0241f81993fe:~/firedrake/src/animate/demos$ python bubble_shear.py
Relative L2 error on the coarse mesh: 56.52%
Relative L2 error on the fine mesh: 32.29%.
Classical mesh adaptation.
   Avg. number of vertices: 2299.5
   Relative L2 error: 30.43%
Metric advection mesh adaptation.
   Avg. number of vertices: 2008.3
   Relative L2 error: 30.58%
   
   
(firedrake) firedrake@0241f81993fe:~/firedrake/src/animate/demos$ python bubble_shear.py -log_view :foo.txt:ascii_flamegraph
Relative L2 error on the coarse mesh: 56.52%
Relative L2 error on the fine mesh: 32.29%.
Classical mesh adaptation.
   Avg. number of vertices: 2308.1
   Relative L2 error: 30.32%
Metric advection mesh adaptation.
   Avg. number of vertices: 2014.3
   Relative L2 error: 30.79%

[jwallwork23]

Very interesting... Even logging affects adaptive results:

Is this with float or R-space?

[ddundo]

Very interesting... Even logging affects adaptive results:

Is this with float or R-space?

This is on the 153_improve_bubble branch, so with R-space.

[jwallwork23]

Hm, are there any other floats that might be causing an issue?

[ddundo]

Not sure, but I'll try to make minimal examples for each of these before the next meeting so we can discuss :)