title: how to remove empty values in dc.js row chart
body: <p>I'm making a rowchart using the Dimensional Charting javascript library dc.js, which is based on d3 and crossfilter. I have created a row chart from the sale column. </p>
  
  <p>I am having some issues in removing empty bins from a rowChart.</p>
  
  <p>My csv file:</p>
  
  <pre><code> partner    sale
    AMZ       newyear
    HD        newyear
    WAF       fallmake
    FEG       fallmake
    OVR       
    AMZ       fallmake
    FAU       balck
    HD         
    ATG       balck
  </code></pre>
  
  <p>My code:</p>
  
  <pre><code> saleDim = ndx.dimension(function (d) { return d.sale; }),
   salegroup = saleDim.group().reduceCount(),
   nonEmptyHist11 = remove_bins(salegroup);
  </code></pre>
  
  <p>I have tried to remove empty sales bins using the following function:</p>
  
  <pre><code>function remove_bins(source_group) { // (source_group, bins...}
      return {
          all: function () {
              return source_group.all().filter(function (d) {
                  return d.sale!= null;
              });
          }
      };
  }
  </code></pre>
  
  <p>My graph looks like this:</p>
  
  <p><a href="https://i.stack.imgur.com/2zD2B.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/2zD2B.png" alt="enter image description here"></a></p>