[MATH-927] GammaDistribution cloning broken

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.1
• Fix Version/s: 3.1.1
• Assignee: Unassigned
• Reporter: Dennis Hendriks
• Created: 04/Jan/13 11:36
• Updated: 04/Mar/13 18:53
• Resolved: 13/Jan/13 18:02

Description

Serializing a GammaDistribution and deserializing it, does not result in a cloned distribution that produces the same samples.

Cause: GammaDistribution inherits from AbstractRealDistribution, which implements Serializable. AbstractRealDistribution has random, in which we have a Well19937c instance, which inherits from AbstractWell. AbstractWell implements Serializable. AbstractWell inherits from BitsStreamGenerator, which is not Serializable, but does have a private field 'nextGaussian'.

Solution: Make BitStreamGenerator implement Serializable as well.

This probably affects other distributions as well.