Understanding output of perfcurve

[X,Y,T,AUC2,OPTROCPT] = perfcurve(classtest,classpredict,2);

My classtest as well as classpredict are 460*1, but when i run perfcurve i get x 3*1 and so it y.

I do not understand why is it so. As X,Y are used to draw ROC, I think it should give both of them as 460*1. I must be missing something.

Thank you for your time.

Answer 1

[Tom Lane]

Could it be that you have relatively few distinct values of classpredict?

[Nirmal]

Thank you! i really didnt think it through.