[MATH-701] Seeding a default RNG

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.0
• Assignee: Gilles Sadowski
• Reporter: Gilles Sadowski
• Created: 03/Nov/11 13:26
• Updated: 24/Mar/12 16:16
• Resolved: 05/Nov/11 06:50

Description

In "RandomDataImpl":

private RandomGenerator getRan() {
    if (rand == null) {
        rand = new JDKRandomGenerator();
        rand.setSeed(System.currentTimeMillis());
    }
    return rand;
}

The conditional branch is used by "sample()" in "AbstractContinuousDistribution".

When several "...Distribution" objects are instantiated in a short time interval, they are seeded with the same value.

Issue Links

• incorporates: MATH-720 RandomDataImpl uses both JDKRandomGenerator and Well19937c, while contract/javadoc only specifies Well19937c.