Should we display the pos label in the axis labels or in the title of the plot?

Do we restrict this to response_method='predict_proba'?

Should we display the pos label in the axis labels or in the title of the plot?

I think it would be great indeed.

Do we restrict this to response_method='predict_proba'?

I did not think yet at the decision function but I think that we should come with a fix as well. I am looking at it now.

Basically we will be fine with decision_function since we are giving the y_pred which is 1D and pos_label to the precision_recall_curve function which will manage properly the issue with those.

The probability is more problematic because precision_recall_curve should be a 1D array and we have to do the job before to pass the function.

I think that the question of @amueller in #15573 should be addressed. Is pos_label the right parameter name with its slightly semantic being different from the precision_recall_curve for instance.

We are using pos_label to do two things here:

1. Select the positive class from classes_
2. Passing to precision_recall_curve which selects the positive class from y_true.

So in the sense of 2, we have the same semantics. I think the semantics for 1 is clear enough compared to the cost of introducing another parameter name.

Fair enough with me. Would we consider this as a bug fix or an enhancement?

Adding a new parameter feels like an enhancement.

is this ready to be closed? if so can someone please close it? (@thomasjpfan) I'm working on #15573 and would like to make my changes on top of these ones

This needs a second reviewer to approve before it can get merged.

so what is the best thing to do? should I merge this branch into mine? or should I make my changes and then solve possible conflicts once this branch is approved?

@claramatos the second indeed. Just make your changes against master for now and later resolve conflicts. You could also base your PR on this one but github doesn't have good PR dependency tracking, so this is a bit hard to disentangle.

I'll be a bit annoying here. Anybody able to make a second review and a potential merge @ogrisel @jeremiedbb @amueller @NicolasHug