Adjusting markersize in `prediction_error` about yellowbrick

[rebeccabilbro]

Hello @LSYS and thank you for using Yellowbrick!

This is an excellent question. Full response below, but the tl;dr is that the behavior you're requesting isn't currently possible, though if you are willing to work on this and open a PR, it probably wouldn't be too hard to add support for changing marker size in PredictionError.

Ok, the details:

For most YB plots that plot points or scatterplots, the marker size is left to the default of whatever Matplotlib sets the size/shape to. The one exception is ValidationCurve, which allows the user to pass in a markers param that gets used inside the draw method to influence the markers. This is a fairly recent change implemented by @lwgray , who may have some additional thoughts here. It should be possible to make similar changes to the PredictionError constructor to take in a user-provided param that gets invoked inside the draw method.

If you're interested in moving forward with contributing, check out the contributor docs and let us know; I'd be happy to help coach you through and review your PR.

[LSYS]

@rebeccabilbro Thanks so much for the fast and detailed response. When I have time I'll look in a bit more detail at the API design of yellowbrick to see if I can contribute. Perhaps learning how yellowbrick interfaces with matplotlib would also be helpful for my own work.

Thanks again! Closing this issue (for now).