CODE EXAMPLE FOR JAVASCRIPT

map values in range js

function mapValues(value, oldRange, newRange) {
    var newValue = (value - oldRange[0]) * (newRange[1] - newRange[0]) / (oldRange[1] - oldRange[0]) + newRange[0];
    return Math.min(Math.max(newValue, newRange[0]) , newRange[1]);
}