Thanks for this (and sorry for delay in looking at it). There does seem to be quite a bit of duplicated code, could you perhaps inherit Profile from Minimize (or both from a common ancestor), so that common code can be reused? (e.g. _get_desc seems basically copied, and other code e.g. setting up minimizers could also probably be refactored into an inherited method?).

Hello @cmbant and happy New Year :)
Yeah, I agree with that. I wasn't sure it was a good idea to design a sampler that inherits from another one, but, since you suggest doing so, I will refactor this to include the least new code possible.
I guess this will make it easier to maintain too.

I'll come back to you when I have relevant news (it may take some time since I am also writing my manuscript ): )

Hello @cmbant, I tried to inherit from Minimizer to define the Profiler and comment out all the code that was duplicated.

Still, I cannot see the log from Travis to understand what is breaking.
I don't know if it is a problem due to me not having a subscription.

Do you have any insight?

Yeah, I see the job, but the log only gives this message:

We're sorry, but this data is not available. Please check the repository settings in Travis CI.

Try in a new incongito window, that works fine for me:
https://app.travis-ci.com/github/CobayaSampler/cobaya/jobs/617467186

That worked!
I'll proceed with the implementation then, thanks!

Ok, now it works.

I inherited from Minimize as you suggested and try to recycle as much code as possible. If I didn't miss some possible shortcuts, I should have kept only the necessary lines.

To initialize the points I rely on multiple initializations of Minimize. Then, I drop the profiled parameter from the relevant quantities. This saves quite a lot of lines in the profile sampler.
Then, I think I cannot avoid to "overwrite" the run method. I tried to recycle the Minimize one but it must be model-specific (I define different models for each value of the profiled parameter) and I cannot modify the model Minimize uses (as far as I know).
Also, the processing of the results and the relative products are modified wrt Minimize.

Let me know if you think I could improve it in some way. Still, I'll keep improving it if I can.

Thanks, looks good. I don't think you need to inherit from CovmatSampler again as Minimize already does.

Jesus suggests you consider making this an external package (which means you'd more obviously get credit for it! And reduce code bloat/maintainance in cobaya itself). You can use external samplers (as for external likelihood packages), though in this case we may need to make some small changes to run.py etc which Jesus said he could help with.

Hi @ggalloni

I am very sorry for the delay on this.

Could you please create a minimal package with just the sampler code following the example repo at https://github.com/CobayaSampler/example_sampler/? And then please try to import it in the input as [package.Class] as in the example code? I just want to make sure that it can be imported that way. It won't fully work, of course, because we need to merge the changes in this PR for the general Cobaya files, but we will do that this week. But first let's check that the packaging works.

@cmbant the example external sampler works the same as the likelihoods. If it's a package that has been created explicitly for Cobaya, it's a bit of a shame that we need to import as [package.Class]. Maybe if we agree on a general class name, such as CobayaWrapper for the Sampler-inherited class, we can invoke just using the package name? Not very important, just to have your opinion.

@cmbant Thanks! Updated. We have some many ways to interface that I often do not remember all of them.

Hi @JesusTorrado,

here you can find the module with the profile sampler.

I tested it both with tests and by running locally cobaya-run run_profile_example.yaml, and it works fine.

Note that I had to specify a python_path in the example yaml to make it work properly with cobaya-run.
I guess this also applies to your example_sampler as I couldn't run it without doing the same.
Am I doing something wrong?

Let me know if you need me to do something else.

Hi @ggalloni

Sorry, I forgot to add that it works without the python_path only if it has been installed with pip. I just checked that it does work for my example_sampler and your profiler when they are pip-installed (otherwise, python_path is needed). So nothing to do there (but you may want to clarify it in your docs).

Let me see about the rest of the changes in the PR. I will propose another one soon handling the documentation part, but let's keep this open until then.

But in any case, your profiler works now as an external package, so I would personally drop the reference to the PR in the README and make it standalone.

Great, thanks!

I'll work on the README asap 👍

No worries, and apologies again for the huge delay!