function drawCustom(data) {
  var scale = d3.scale.linear()
    .range([10, 390])
    .domain(d3.extent(data));

  var dataBinding = dataContainer.selectAll("custom.rect")
    .data(data, function(d) { return d; });

  dataBinding
    .attr("size", 8)
    .transition()
    .duration(1000)
    .attr("size", 15)
    .attr("fillStyle", "green");

  // enter is same...

  dataBinding.exit()
    .attr("size", 8)
    .transition()
    .duration(1000)
    .attr("size", 5)
    .attr("fillStyle", "lightgrey");
}