title: D3 force layout change showed links with slider
body: <p>I have a problem with this d3 force layout:</p>
  
  <p><a href="http://plnkr.co/edit/UJqNumlkl9rt8WGGOKYm?p=preview" rel="nofollow">http://plnkr.co/edit/UJqNumlkl9rt8WGGOKYm?p=preview</a></p>
  
  <p>I am trying to show only the links whose value is equal to the value of the slider. However it only works when loading the data, when I slide the slider it does nothing and I don't understand why. This is the code for changing the link width</p>
  
  <pre><code>var link = svg.selectAll(".link")
      .data(graph.links)
      .enter().append("line")
      .attr("class", "link")
      .style("stroke-width", function(d) {
          return d.value == slider.value() ? 3 : 0;
      });
  </code></pre>
  
  <p>Can someone help me please?</p>