Random selection function for weighted array elements

Asked Feb 03 '18 at 12:58

Active Feb 03 '18 at 13:07

Viewed 74 times

In the initial state we've got a list of elements having different weights from zero to one.

let list = [
  0.1,
  0.83,
  0.65,
  0.9,
  0.23,
  0.17,
  0.87,
  0.34
];

In the final state we will need to pick only one element, though the probability should influence the result by its weight.

Question: How should the selection function look like, to solve that mathematical problem?

asked Feb 03 '18 at 12:58

I can't even articulate how that mathematical problem is called. If you can help me to find the correct nomenclature, it will be a huge aid! – Michael W. Czechowski Feb 03 '18 at 13:01
@barmar im reopening cause the dupe answers are not satisfying IMO – Jonas Wilms Feb 03 '18 at 13:03
@JonasW. There should be other questions that do satisfy. This is a common question. – Barmar Feb 03 '18 at 13:03
How about: https://stackoverflow.com/questions/8435183/generate-a-weighted-random-number – Barmar Feb 03 '18 at 13:05
@barmar yes thats better. Found that a second ago ;) – Jonas Wilms Feb 03 '18 at 13:06
1

You could do something like this https://jsfiddle.net/Lg0wyt9u/2718/ – Nenad Vracar Feb 03 '18 at 13:09
@NenadVracar Thank you for you post, please add it as an answer. I love your one-liner. I've published it also here: https://beta.observablehq.com/@nextlevelshit/rejection-sampling-in-javascript – Michael W. Czechowski Feb 03 '18 at 13:44
@NEXTLEVELSHIT The question is closed now. – Nenad Vracar Feb 03 '18 at 13:50
Can't understand it, because you gave a new way to fix that problem. Sorry! – Michael W. Czechowski Feb 03 '18 at 14:20
1

@NenadVracar You could add it as an answer to the linked question. – Barmar Feb 04 '18 at 05:43

0 Answers0