Hands on the RandomDataGenerator class in Apache Commons Math

Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

%classpath add mvn org.apache.commons commons-math3 3.6.1

import org.apache.commons.math3.random.RandomDataGenerator
import collection.JavaConverters._
val rng = new RandomDataGenerator()

scala.collection.JavaConverters$@783d0556

RandomDataGenerator.nextInt¶

Notice that the both of the endpoints are included, which is different from typcial Java conventions!!!

rng.nextInt(0, 2)

2

rng.nextInt(0, 1)

1

rng.nextInt(0, 1)

0

rng.nextPermutation(5, 3)

[4, 3, 0]

rng.nextPermutation(5, 3)

[2, 3, 0]

val vec = Vector(10, 20, 30, 40, 50)

[[10, 20, 30, 40, 50]]

rng.nextSample(vec.asJava, 3).mkString(" ")

50 20 10

rng.nextSample(vec.asJava, 3).mkString(" ")

50 30 40