This example demonstrates D3.js force directed layout with fixed x-values and a band on the y-axis where source nodes will not be placed. Target nodes are fixed at y = 0.
Color Scheme: http://colorschemedesigner.com/#3q61Uw0w0w0w0
Modified http://d3js.org/d3.v3.min.js to a secure url
https://d3js.org/d3.v3.min.js
https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js
https://ajax.googleapis.com/ajax/libs/jqueryui/1.10.2/jquery-ui.min.js