Seedable Random Number Generator in Typescript

RNG.ts

export class RNG {
    private seed:number;

    constructor(seed:number) {
        this.seed = seed;
    }

    private next(min:number, max:number):number {
        max = max || 0;
        min = min || 0;

        this.seed = (this.seed * 9301 + 49297) % 233280;
        var rnd = this.seed / 233280;

        return min + rnd * (max - min);
    }

    // http://indiegamr.com/generate-repeatable-random-numbers-in-js/
    public nextInt(min:number, max:number):number {
        return Math.round(this.next(min, max));
    }

    public nextDouble():number {
        return this.next(0, 1);
    }

    public pick(collection:any[]):any {
        return collection[this.nextInt(0, collection.length - 1)];
    }
}

In reference to @makoConstruct suggestions:

• it is not necessary to change the value, the modulus already reduces the range to "less than" so the division is correct as written
• it is however critical to change the 'round' to a 'floor' (because otherwise the integer value '0' is picked only half as many times as other values)

I ran a quick test to check distribution after this change:

       // NOTE: I modified the class to static, the logic remains the same
        RNG.seed = 12345;
        let r:Array<number> = new Array<number>(11);
        for(let i:number = 0; i < 11; i++)
            r[i] = 0;
        for(let i:number = 0; i < 1000000; i++)
            r[RNG.nextInt(0,10)]++;
        for(let i:number = 0; i < 11; i++)
            console.log(i + " = " + r[i]);

which results in values:

0 = 100004
1 = 100016
2 = 99986
3 = 100000
4 = 100026
5 = 100008
6 = 99956
7 = 100035
8 = 99977
9 = 99992
10 = 0

(Similar tests with different seeds and ranges also produced reasonable looking distributions)
EDIT: I recommend throwing an 'abs' in for the seed too, I think negative seed values might mess up the algebra

When changing to floor, you also have to change pick (remove the -1):

public pick(collection:any[]):any {
return collection[this.nextInt(0, collection.length)];
}

otherwhise the last element is never picked, because max is no longer inclusive.