D3.js - Donut charts with multiple rings and animation transition

Question

How can you add a transition animation effect to the following D3 chart with multiple rings?

As shown here D3.js - Donut charts with multiple rings

var dataset = {
                apples: [53245, 28479, 19697, 24037, 40245],
                oranges: [53, 28, 19, 24],
                lemons: [53245, 28479, 19697, 24037, 40245],
                pears: [53245, 28479, 19697, 24037, 40245],
                pineapples: [53245, 28479, 19697, 24037, 40245],
            };

            var width = 460,
                height = 300,
                cwidth = 25;

            var color = d3.scale.category20();

            var pie = d3.layout.pie()
                .sort(null);

            var arc = d3.svg.arc();

            var svg = d3.select("#chart").append("svg")
                .attr("width", width)
                .attr("height", height)
                .append("g")
                .attr("transform", "translate(" + width / 2 + "," + height / 2 + ")");

            var gs = svg.selectAll("g").data(d3.values(dataset)).enter().append("g");
            var path = gs.selectAll("path")
                .data(function (d) { return pie(d); })
                .enter().append("path")
                .attr("fill", function (d, i) { return color(i); })
                .attr("d", function (d, i, j) { return arc.innerRadius(10 + cwidth * j).outerRadius(cwidth * (j + 1))(d); });

<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.4.11/d3.min.js"></script>

<div id="chart" width="600" height="400"></div>

Answer 1

You need to add the .transition method to your vis

var path = gs.selectAll("path")
    .data(function(d) { return pie(d); })
  .enter().append("path")
//added line//
    .transition().duration(750).attrTween("d", arcTween)
    .attr("fill", function(d, i) { return color(i); })
    .attr("d", function(d, i, j) { return arc.innerRadius(10+cwidth*j).outerRadius(cwidth*(j+1))(d); });

//added tween function
function arcTween(a) {
  var i = d3.interpolate(this._current, a);
  this._current = i(0);
  return function(t) {
    return arc(i(t));
  };
}

I just referenced this site

Here is a forked fiddle

It's not clear as to how you want to animate the charts.