title: Relation between LinkDistance and LinkStrength in D3.js Force layout
body: <p>How are the LinkDistance and LinkStrength related in a force directed layout in D3.js? I am assuming that they are, correct me if i am wrong. </p>
  
  <p>I understand that the linkDistance defines the length between any pair of nodes and essentially serves as constraint in a force layout. But what role does linkStrength play? The API documentation for D3.js defines it as the "strength (rigidity) of links to the specified value in the range [0,1]" What does "rigidity" mean here exactly?</p>