Question

I’m trying to generate several random doublesbetween 0 and 1. This is the code I ran but the numbers coming back are very close together. I want numbers that are uniformally distributed over [0,1] or at least [0,1). I

public class MyClass
long seed = System.currentTimeMillis();
......
public double returnRandom() {
    Random rand = new Random();
    seed += 4; //update the seed
    rand.setSeed(seed); 
    return rand.nextDouble();
}

(loop over array to populate) I end up with:

[0.10233441769044727]

[0.10484270731218648]

[0.1044843653222054]

[0.10412603823338551]

Answer 1

I would recommend that you not update the seed. You should also make Random a class instance and not instantiate one every time you call that method.

public class MyClass {
    private Random random = new Random(System.currentTimeMillis());

public double returnRandom() {
    return this.random.nextDouble();
}
}