... has it really been removed from version 16 of JMP ... I don't see it anymore?
It hasn't been removed, but you cannot see it in red triangle anymore (no idea why).
Names Default To Here(1); dt = Open("$SAMPLE_DATA/Car Poll.jmp"); obj = dt << Partition( Y(:country), X(:sex, :marital status, :age, :type, :size), Split Best(2) ); obj << K Fold Crossvalidation(5);
Also you can see it in preferences:
But if you enable it, it will launch every time.
Also: Bring back the crossvalidation option in Partition platform menu
K-Fold of a partition model can be done using the Model Screening platform. K-fold is done in a more useful way there.
It was removed from the Partition platform because the folds were not independent of the tree-cut decisions. This can lead to overfitting of the tree model, especially prior to version 15. Steps were made to correct this in v15, but still not satisfactorily. Instead, better functionality was placed in the Model Screening platform.
The deprecation was not mentioned in JMP 16 but this change is not mentioned in the New Features document. It is noted in the Scripting Index with the message syntax.