[MATH-197] RandomDataImpl.nextPoisson() is extreme slow for large lambdas

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.0, 1.1, 1.2
• Fix Version/s: 2.0

Environment

jdk1.6.0_04, windows xp

• Assignee: Brent Worden
• Reporter: Tolja Zubow
• Created: 17/Mar/08 11:55
• Updated: 07/Aug/09 09:19
• Resolved: 21/Jun/09 15:10

Description

The RandomDataImpl.nextPoisson() is extreme slow for large lambdas:

E.g. drawing 100 random numbers with lambda = 1000 takes around 10s on my dual core with 2.2GHz.
With lambda smaller than 500 everything is fine. Any ideas?

RandomDataImpl r = new RandomDataImpl();
r.reSeed(101);

int d = 100;
long poissonLambda = 1000;

long st = System.currentTimeMillis();
for (int row = 0; row < d; row++)

{ long nxtRnd = r.nextPoisson(poissonLambda); }

System.out.println("delta " + (System.currentTimeMillis() - st));