Random Graph D3

randomGraph

function getRandomInt(min, max) {
    return Math.floor(Math.random() * (max - min + 1)) + min;
}

// # groups added by Cam
function erdosRenyi(nodesNum,directedness,prob,groups) {
    
  // create nodes list
  var nodes = []
  for (var i = 0; i < nodesNum; i++) {
      var name = function(i) { return toString(i);};
      var group = getRandomInt(1,groups);
//    nodes.push(i);
      nodes.push({"name":name, "group":group});
  }
  
  // init edges
  var edges = [];
  
  for (var i = 0; i < nodes.length; i++) {
    for (var j = i+1; j < nodes.length; j++) {
      var pchance = Math.random()

      if (pchance < prob) {  // changed by Cam from > to <
        if (directedness === 0) {
          edges.push({"source":i,"target":j,"directedness":0});
        }
        else {
          var dchance = Math.random();
          if (dchance > prob) {
            edges.push({"source":i,"target":j,"directedness":1})
            edges.push({"source":j,"target":i,"directedness":1})
          }
          else {
            edges.push({"source":i,"target":j,"directedness":1})
            // need to fix - can't be i or j!
            var rando = getRandomInt(0,nodes.length);
            edges.push({"source":getRandomInt(0,nodes.length),"target":i,"directedness":1})
          }
        }
      }
    }
  }
  
  return {"nodes":nodes, "links":edges};
//return {"nodes":nodes.map(function(m) { return {"name":m.toString()};}), "links":edges};
  
}

var width = 500;
var height = 250;
    
var svg = d3.select("#chart")
        .append("svg")
        .attr("width", width)
        .attr("height", height)
//        .style('border', '1px solid red')
        ;

graph = erdosRenyi(10,0,0.2,5);
console.log(graph);
    
    var color = d3.scale.category20();

    var force = d3.layout.force()
        .charge(-100)
        .linkDistance(30)
        .size([width, height]);

      force
          .nodes(graph.nodes)
          .links(graph.links)
          .start();

      var link = svg.selectAll(".link")
          .data(graph.links)
        .enter().append("line")
          .attr("class", "link")
          .style("stroke-width", 4)
      ;

      var node = svg.selectAll(".node")
          .data(graph.nodes)
        .enter().append("circle")
          .attr("class", "node")
          .attr("r", 5) // function(d) { return d.value; })
          .style("fill", function(d) { return color(d.group); })
          .call(force.drag);

//      node.append("title")
//          .text(function(d) { return d.name; });

      force.on("tick", function() {
        link.attr("x1", function(d) { return d.source.x; })
            .attr("y1", function(d) { return d.source.y; })
            .attr("x2", function(d) { return d.target.x; })
            .attr("y2", function(d) { return d.target.y; });

        node.attr("cx", function(d) { return d.x; })
            .attr("cy", function(d) { return d.y; });
      });
    
// Button click triggers transition
    function endall(transition, callback) { 
        var n = 0; 
        transition 
            .each(function() { ++n; }) 
            .each("end", function() { if (!--n) callback.apply(this, arguments); }); 
    } 
    
    d3.select("#button")
        .on("click", function() {
            console.log('click');
        
          force.stop();
        
        // first withdraw all links, then extend them to new spots
        link.data(graph.links).transition().duration(1000)
            .attr("x1", function(d) { return d.source.x; })
            .attr("y1", function(d) { return d.source.y; })
            .attr("x2", function(d) { return d.source.x; })
            .attr("y2", function(d) { return d.source.y;})
            .call(endall, function() {
                graph.links = erdosRenyi(10,0,0.2,5).links;
            
                link.data(graph.links).transition()
                .duration(1000)
                .attr("x1", function(d) { return d.source.x; })
                .attr("y1", function(d) { return d.source.y; })
                .attr("x2", function(d) { return d.target.x; })
                .attr("y2", function(d) { return d.target.y; })
                .call(endall, function() {
                    force
                      .links(graph.links);

                    force.start();            
                });
            });

//            updateChart();					   				
    });