Is there a map function in vanilla javascript like p5.js?

Question

In p5.js, theres a function called map() which maps a value in a certain range to another value in another range. Is there a similar method like this in vanilla javascript?

@xander: That's not [the kind of map the OP wants](https://p5js.org/reference/#/p5/map). — Ilmari Karonen, Feb 15 '18 at 08:40
@IlmariKaronen you're right, but an example in the question would have helped I guess. And it's pretty simple to implement a range mapping like that in a simple way. — xander, Feb 15 '18 at 08:42
Check [Javascript / jQuery - map a range of numbers to another range of numbers](https://stackoverflow.com/questions/10756313/javascript-jquery-map-a-range-of-numbers-to-another-range-of-numbers). — user2314737, Feb 15 '18 at 08:45

score 7 · Answer 1 · edited Feb 15 '18 at 16:46

No, there isn't anything like that in JavaScript out of the box, but it's easy enough to write your own:

// linearly maps value from the range (a..b) to (c..d)
function mapRange (value, a, b, c, d) {
    // first map value from (a..b) to (0..1)
    value = (value - a) / (b - a);
    // then map it from (0..1) to (c..d) and return it
    return c + value * (d - c);
}

Also, P5.js is written in JavaScript, so its map() function is vanially JavaScript. P5.js is open-source, and the map() function can be found here:

var newval = (n - start1) / (stop1 - start1) * (stop2 - start2) + start2;

Is there a map function in vanilla javascript like p5.js?

1 Answers1