Add option to use t0 embedding features

[dfulu]

Pull Request

Description

This adds the option to use the t0-embedding features which were added to data-sampler in openclimatefix/ocf-data-sampler#385 in PVNet

Checklist:

• My code follows OCF's coding style guidelines
• I have performed a self-review of my own code
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• I have checked my code and corrected any misspellings

[peterdudfield]

This might be my lack of understanding, but is it obvious how know the t0_embedding_dim from the t0_embedding embedding (below)?

[dfulu]

Well in the function docstring it explains that the embedding_dim parameter is for the location ID. We could rename embedding_dim->loc_embedding_dim or something similar to be more explicit. But for that we'd need to migrate all our production models

[dfulu]

Oh sorry, I think I misunderstood your question. You mean how can you know what the t0_embedding_dim needs to be given t0_embedding config? That info is in data-sampler.

Basically:

t0_embedding_dim = sum([1 if e=="linear" else 2 for e in t0_embedding.embeddings])

[peterdudfield]

ah i see, could you put this comment in the docstrings? (Or if there somewhere else more suitable)

[dfulu]

This feels like bloat here since it is explained in full in data-sampler

[dfulu]

Maybe a compromise is to put the explanation in the example config

[peterdudfield]

Other than my questions, this looks good and clear