Fast real valued random generator in java

Question

java.util.Random.nextDouble() is slow for me and I need something really fast.

I did some google search and I\'ve found only integers based fast random generators.

Answer 1

If you need something fast and have access to Java8, I can recommend the java.utils SplitableRandom. It is faster (~twice as fast) and has better statistical distribution.

If you need a even faster or better algorithm I can recommend one of these specialized XorShift variants:

• XorShift128PlusRandom (faster & better)
• XorShift1024StarPhiRandom (similar speed, even longer period)

Information on these algorithms and their quality can be found in this big PRNG comparison.

I made an independent Performance comparison you can find the detailed results and the code here: github.com/tobijdc/PRNG-Performance

TLDR

Never use java.util.Random, use java.util.SplittableRandom. If you need faster or better PRNG use a XorShift variant.