Refactor simulate_for_sbi location

[samadpls]

What does this implement/fix? Explain your changes

Move simulate_for_sbi to utils

Does this close any currently open issues?

Fixes #1240

Checklist

Put an x in the boxes that apply. You can also fill these out after creating
the PR. If you're unsure about any of them, don't hesitate to ask. We're here to
help! This is simply a reminder of what we are going to look for before merging
your code.

• I have read and understood the contribution
  guidelines
• I agree with re-licensing my contribution from AGPLv3 to Apache-2.0.
• I have commented my code, particularly in hard-to-understand areas
• I have added tests that prove my fix is effective or that my feature works
• I have reported how long the new tests run and potentially marked them
  with pytest.mark.slow.
• New and existing unit tests pass locally with my changes
• I performed linting and formatting as described in the contribution
  guidelines
• I rebased on main (or there are no conflicts with main)
• For reviewer: The continuous deployment (CD) workflow are passing.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 78.33%. Comparing base (8afd985) to head (47768a3).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1253      +/-   ##
==========================================
- Coverage   86.05%   78.33%   -7.73%     
==========================================
  Files         118      119       +1     
  Lines        8672     8685      +13     
==========================================
- Hits         7463     6803     -660     
- Misses       1209     1882     +673     

Flag	Coverage Δ
unittests	78.33% <100.00%> (-7.73%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
sbi/inference/__init__.py	100.00% <100.00%> (ø)
sbi/inference/trainers/base.py	92.54% <100.00%> (+5.63%)	⬆️
sbi/utils/simulation_utils.py	100.00% <100.00%> (ø)

... and 28 files with indirect coverage changes

[janfb]

That looks good, thanks a lot!

Now that you have moved the code, codecov notices that parts of the simulate_for_sbi function are not covered in tests.

Would you be up for writing a test that tests simulate_for_sbi with different cases, e.g., with num_simulations=0, simulation_batch_size=None, num_workers>1, using pytest.mark.parametrize?

You could just use a linear_gaussian simulator as in the other tests.
Ideally, you would also add one case where we run process_simulator and one where we don't, to cover the TypeError case when num_workers>1.

Let me know whether anything is unclear, or if you prefer not adding this (then I can easily add it in a separate PR).

Thanks again, cheers,
Jan

[samadpls]

Thanks a lot for the feedback!
I’ve added the tests for simulate_for_sbi covering various cases. Let me know if there’s anything else!

[janfb]

Great! thanks for adding the test as well.

I added a couple of comments. Regarding the TypeError handling, we just need to cover the case where the user passes a torch simulator with num_workers>1 without processing this simulator using process_simulator before. In that case, a TypeError will occur, be handled internally and then raised again. See comment, and let me know if anything is unclear.
Thanks!

[janfb]

Awesome, this looks good!
Thanks a lot 🙏