Can we remove training data from emulator class?

[jchavesmontero]

Removing it would reduce a lot the memory footprint, and in principle, we only need it for training an emulator, not for loading a pre-trained emulator

[andreufont]

Don't we need it for GP emulators? I guess it could be optional if NN don't use it

[andreufont]

Even GP only need the polynomials, not the P1D themselves, so maybe we only need to store that?

[jchavesmontero]

Only storing the polynomials would be a great solution since these occupy much less space than the training_data