Code

randomPositionInCircle.js

// Random generator of position in circle
// Test out on http://testdata.kutac.cz/nahodna-pozice-v-kruhu/

function getCircleRandomPosition(radius){
    a = Math.random();
    b = Math.random();
    var ret = {
        x: 0,
        y: 0
    }
    if (a > 0 || b > 0) {
        if (b < a) {
            var x = a;
            a = b;
            b = x;
        }
        ret.x = radius * b * Math.cos(2 * Math.PI * a/b);
        ret.y = radius * b * Math.sin(2 * Math.PI * a/b);
    }
    return ret;
}