Ico.js

Ico.Base = Class.create({
  /* Returns a suitable set of labels for given data points on the Y axis */
  labelStep: function(data) {
    var min = data.min(),
        max = data.max(),
        range = max - min,
        step = 0;

    if (range < 2) {
      step = 0.1;
    } else if (range < 3) {
      step = 0.2;
    } else if (range < 5) {
      step = 0.5;
    } else if (range < 11) {
      step = 1;
    } else if (range < 50) {
      step = 5;
    } else if (range < 100) {
      step = 10;
    } else {
      step = Math.pow(10, (Math.log(range) / Math.LN10).round() - 1);
    }
    
    return step;
  }
});