`VennAbersCalibrator.predict_proba` does not expose `p0_p1_output` parameter

[shafayetShafee]

Hi team,

I noticed that VennAbersCalibrator relies internally on the VennAbers class. The underlying VennAbers.predict_proba method supports the p0_p1_output parameter, which allows returning the (p0, p1) pair instead of the averaged calibrated probability.

In the current MAPIE implementation, however, this parameter is not exposed in VennAbersCalibrator.predict_proba. It appears that p0_p1_output is effectively fixed to False internally, and users cannot control this behavior through the public API.

Why this matters
In some workflows, it can be useful to access the raw (p0, p1) outputs rather than only the averaged calibrated probability. For example, the interval (p0, p1) may be reported alongside the calibrated probability as a measure of uncertainty.

Since the underlying VennAbers implementation already supports this functionality, exposing the p0_p1_output parameter in the MAPIE wrapper would increase flexibility without altering default behavior.

Would it be possible to expose this parameter in VennAbersCalibrator.predict_proba?

Please let me know if I have misunderstood the intended design or missed something in the implementation.

Thanks for your work on MAPIE!

[GBrelurut]

Hello @shafayetShafee,

Thank you for raising the issue.
We need to look more in details in order to add this functionnality, so it may take some time.
If you ever have the time, don't hesitate to contribute. We would be happy to have you as a contributor.