Ex. 3 in Reactive Bar Chart Article

reactive_bar_example_3.js

function BarChart(svg) {
  this.width = $R.state(200);
  this.height = $R.state(200);
  this.data = $R.state([]);
  var y = $R(BarChart.y).bindTo(this.height, this.data)
}
BarChart.y = function (height, data) {
  return d3.scale.linear()
    .domain([0, d3.max(data, function(d) { return d.value })])
    .range([height, 0]);
}