[MRG+2] ENH/FIX Introduce min_impurity_decrease param for early stopping based on impurity; Deprecate min_impurity_split #8449
Also ref Gilles' comment
This PR tries to stop splitting if the weighted impurity gain after a potential split is not above a user-given threshold...
@amueller Can you try this on your use cases and see if it gives better control than
Generally we don't mention that in docstring. We deprecate it and remove the doc for that param...
Thanks for the review. Have addressed it :) Another round?
@jnothman Could you take a look this too?
It's the same expression your one with the "fractional_weight" and the one documented in the criterion file. It is just that I find the latter easier to read, but it's fine. (I meant having the extra term is right and it wasn't reflected in the documentation)