randomInt([min = 0, ]max)

[mbostock]

We should have a randomInt method that returns an integer greater than or equal to min and less than max.

function randomInt(min, max) {
  if (arguments.length < 2) max = min, min = 0;
  min = Math.floor(min);
  max = Math.floor(max) - min;
  return () => Math.floor(min + Math.random() * max);
}