It holds the behaviour every distribution object shares – how it is displayed, how its parameter confidence intervals are computed, how it is plotted and how a profile likelihood is taken – as protected methods, so the 29 distribution classes inherit one implementation and no part of it is reachable from outside them.

These helpers were ordinary files in a private directory until the classes moved into the prob namespace. Octave does not resolve a private directory from inside a package directory, for a classdef or for a plain function, so the only way to keep them out of the public interface is to make them protected methods of a shared base.

Source Code: prob.ProbabilityDistribution