`atan_2` renamed to `atan2`

[dmitryshribak]

ImportError: cannot import name 'atan_2' from 'ufl' (~/Hydrogym/firedrake/src/ufl/ufl/init.py)

Which version of Firedrake are you using and how do I run it?

[jcallaham]

Looks like the name was changed to atan2 here:

firedrakeproject/ufl@8f44275

Probably the most reliable way to ensure everything is compatible is to use the Docker containers as described here.
The code is based on the version of Firedrake available in that container, which was last built 7 months ago, so probably Firedrake_20231027

@ludgerpaehler should we update the dev container sometime soon? Might break a few things like this, but shouldn't be too hard to fix.

[dmitryshribak]

How do I use the docker container? I am currently using PyCharm with a remote dev system

[ludgerpaehler]

I'll regenerate the Docker images tomorrow-ish, then you should be able to use them again normally.

PyCharm should allow you to boot into a Docker container on a remote machine, but you may have to first start the container, and then attach PyCharm to it afterwards.

[dmitryshribak]

I have the docker working, but now the examples do not have solvers? What solver should I use if not IPCS?

[ludgerpaehler]

Here is what was run for the actual paper benchmarks:

flow_dict = {
    "flow": hydrogym.firedrake.Cylinder,
    "flow_config": {
        "Re": args.reynolds_number,
        "mesh": args.mesh_resolution,
    },
    "solver": hydrogym.firedrake.SemiImplicitBDF,
    "solver_config": {
        "dt": args.time_step,
    },
    "callbacks": [log],
    "max_steps": 10000,
}

see here for a contained example: https://github.com/dynamicslab/hydrogym/blob/lp/bug-hunting/reproducer_rewrite_ppo_train.py

Inclined to let this issue auto-close with the merge of the PR.