Java - Generating Random Numbers in java between 0.5 and 6.28

Question

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Generating random number in a range with Java

My code is generating random numbers between 0 and 1. I need to generate a random number between 0.5 and 6.28.

My current Code:

public class Random_Number_Generator
{
    double randomGenerator()
    {
        Random generator = new Random();
        double num = generator.nextDouble();

        return num;
    }
}

Denys Séguret · Accepted Answer · 2012-09-11T15:00:35.913

13

double num = generator.nextDouble()*(6.28-0.5) + 0.5;

As nextDouble returns a number in [0, 1[, you generally have to do

double num = generator.nextDouble()*(max-min) + min;

when you want a number in [min, max[.

edited Sep 11 '12 at 15:00

answered Sep 11 '12 at 14:55

Denys Séguret

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2

can you please explain how this works ? Also, if i want to generate between 0 & 0.5...what would it be ? – Rahul Bhatia Sep 11 '12 at 14:57
1

nextDouble() returns a double between 0 and 1. If you want a double between 0 and 0.5, you do `generator.nextDouble()*0.5`. – Denys Séguret Sep 11 '12 at 14:58
4

your number is between 0 and 1, so (6.28-0.5 = 5.78) * number is between 0 and 5.78. and that + 0.5 is between 0.5 and 6.28. – assylias Sep 11 '12 at 14:58
so according to this...if i use double num = generator.nextDouble()*(0.5-0); it would generate random numbers between 0 and 0.5 – Rahul Bhatia Sep 11 '12 at 15:01
So will `generator.nextDouble()/2;` – Peter Lawrey Sep 11 '12 at 15:18

Java - Generating Random Numbers in java between 0.5 and 6.28

1 Answers1