Just noted, that for cca_zoo.SCCA_PMD the penalty parameters must be within the range 0-1 (as discussed in this thread with the idea of penalty ranges from 0-1 being more "sklearn-ish" and also to stick to the original R-implementation of the authors) but for models like cca_zoo.GRCCA it can be 0-inf. Maybe it would be a good idea to already describe the penalty ranges in the documentation? Also noted that cca_zoo.SCCA_PMD throws an error when providing values for c > 1 which is nice. However, this could conversely lead users to think that this is some sort of default range for other Sparse CCA classes?