title: DC.JS Pie Chart + Select Deslect from external JavaScript function
body: <p>I am using dc.js (<a href="http://dc-js.github.io/dc.js/" rel="nofollow">http://dc-js.github.io/dc.js/</a>) Which is a wrapper to d3 and crossfilter.
  I want to click the pieChart from dc.js Externally. </p>
  
  <p><a href="http://jsfiddle.net/nishants/Bra2H/47/" rel="nofollow">http://jsfiddle.net/nishants/Bra2H/47/</a></p>
  
  <pre><code>var hitslineChart  = dc.lineChart("#chart-line-hitsperday");
  
  var data = [
          {date: "12/27/2012", http_404: 2, http_200: 190, http_302: 100},
          {date: "12/28/2012", http_404: 2, http_200: 10, http_302: 100},
          {date: "12/29/2012", http_404: 1, http_200: 300, http_302: 200},
          {date: "12/30/2012", http_404: 2, http_200: 90, http_302: 0},
          {date: "12/31/2012", http_404: 2, http_200: 90, http_302: 0},
          {date: "01/01/2013", http_404: 2, http_200: 90, http_302: 0},
          {date: "01/02/2013", http_404: 1, http_200: 10, http_302: 1},
          {date: "01/03/2013", http_404: 2, http_200: 90, http_302: 0},
          {date: "01/04/2013", http_404: 2, http_200: 90, http_302: 0},
          {date: "01/05/2013", http_404: 2, http_200: 90, http_302: 0},
          {date: "01/06/2013", http_404: 2, http_200: 200, http_302: 1},
          {date: "01/07/2013", http_404: 1, http_200: 200, http_302: 100}
          ];
  var ndx = crossfilter(data);
  var parseDate = d3.time.format("%m/%d/%Y").parse;
  data.forEach(function(d) {
      d.date = parseDate(d.date);
      d.total= d.http_404+d.http_200+d.http_302;
      d.Year=d.date.getFullYear();
  });
  
  var dateDim = ndx.dimension(function(d) {return d.date;});
  var hits = dateDim.group().reduceSum(function(d) {return d.total;});
  var minDate = dateDim.bottom(1)[0].date;
  var maxDate = dateDim.top(1)[0].date;
  
  hitslineChart
      .width(500).height(200)
      .dimension(dateDim)
      .group(hits)
      .x(d3.time.scale().domain([minDate,maxDate]))
      .brushOn(false)
      .yAxisLabel("Hits per day");
  
  var yearRingChart   = dc.pieChart("#chart-ring-year");
  var yearDim  = ndx.dimension(function(d) {return +d.Year;});
  var year_total = yearDim.group().reduceSum(function(d) {return d.http_200+d.http_302;});
  
  yearRingChart
  .width(150).height(150)
  .dimension(yearDim)
  .group(year_total)
  .innerRadius(30);
  
  dc.renderAll();
  </code></pre>
  
  <p>I could not find a way to click or call cross filter code external to dc.js widgtes.</p>