               .attr("marker-end", "url(#edge)");

        var shape = svg.append("g").selectAll("use")
                .data(force.nodes())
                .enter().append("use")
                .attr("xlink:href", function(d) { return "#" + d.type + "-symbol" })
                .attr('style', function(d) {
                    var color = d.color;
                    if (/[\.\d]+,[\.\d]+,[\.\d]+/.test(d.color)) {
                        color = d.color.split(",");  
                        color = 'hsl(' +