Add Plot loss

[TheCSGuy25]

Added the Plot Loss Method, that accepts an emulator along with optional plot title and figure size as arguments and will plot the loss with respect to epochs and will raise an AttributeError if the emulator has no loss_history attribute.

[radka-j]

Thank you for adding this @TheCSGuy25, it looks great!

The only thing that needs fixing is the pre-commit and then it's good to merge. Let us know if you need any help with this.

[TheCSGuy25]

Hey @radka-j

I will change the test and exceptions as suggested by the workflow. I have a question related to message that was shown as a part of it

plotting.py:642:25 - error: Cannot access attribute "loss_history" for class "Emulator" Attribute "loss_history" is unknown (reportAttributeAccessIssue) 1 error, 0 warnings, 0 informations

I looked at the base.py and PytorchBackend class has a loss_history object but not the Emulator class. How do i resolve this? As we're passing the emulator not the Base model to the plot_loss method, or should i change it to a PyTorchBackend model?

[radka-j]

@TheCSGuy25 thank you for checking

There are two options:

1. As you say, you could change the type to PyTorchBackend - this is the simplest but I'd prefer to avoid this as we should ideally also be tracking the loss history in the gaussian process emulators (which don't inherit from PyTorchBackend).
2. change the code to something like:

    if not hasattr(model, "loss_history"):
        msg = "Emulator does not have a Loss history"
        raise AttributeError(msg)
    history = model.loss_history

This is essentially what you implemented but should (I think) satisfy the pre-commit check.

Let me know if you have any questions and/or anything else comes up.

[TheCSGuy25]

@radka-j Hello !

So it passed the pre-commit, but now it show's an issue with coverage_from_distributions method from plotting.py

AttributeError: 'Tensor' object has no attribute 'sample'

as well as
No module named 'autoemulate.simulations_design', No module named 'autoemulate.simulations_design

Do let me know how i can help to resolve this.

(Note: I have synced the fork and branches with the main as well)

[radka-j]

@TheCSGuy25 this all looks great! The bug had something to do with the docs and is not related to this PR. Thank you again for implementing this and for your patience with getting the CI to pass :)