jQuery event ratio offsets

example.js

$('.area').on('mousemove', function (e) {
  $.event.ratioOffsets(e);
  console.log(e.ratioOffsetX, e.ratioOffsetY);
});

jquery.event.ratioOffsets.js

// depends on $.event.normalizeOffsets
// see https://gist.github.com/AndersDJohnson/5882463

$.event.ratioOffsets = function (e) {
  $.event.normalizeOffsets(e);
  var $target = $(e.target);
  e.ratioOffsetY = e.normalizedOffsetY / $target.height();
  e.ratioOffsetX = e.normalizedOffsetX / $target.width();
  return e;
};