On mouseover, mark the node you're hovering over, and color its neighbours according to the type of the relationship. This style is only an example and anything goes - from adding icons, respecting asymmetric links (i.e. different markup of employee or manager in an unmutual hierarchy link) and the list goes on.
Not relying on markers etc gives a lot of visual relief.
Based on Mike Bostock's molecule example from: http://bl.ocks.org/mbostock/3037015
| <!DOCTYPE html> | |
| <html> | |
| <head></head> | |
| <body> | |
| <meta charset="utf-8"> | |
| <style> | |
| .link line { | |
| stroke: #696969; | |
| } | |
| .link line.separator { | |
| stroke: #fff; | |
| stroke-width: 2px; | |
| } | |
| .node circle { | |
| stroke: #000; | |
| stroke-width: 1.5px; | |
| } | |
| .node text { | |
| font: 10px sans-serif; | |
| pointer-events: none; | |
| } | |
| circle.active{ | |
| fill: "red"; | |
| } | |
| </style> | |
| <body> | |
| <script src="http://d3js.org/d3.v2.min.js?2.9.6"></script> | |
| <script> | |
| var q; | |
| var width = 960, | |
| height = 500; | |
| var color = d3.scale.category20(); | |
| var radius = d3.scale.sqrt() | |
| .range([0, 6]); | |
| var svg = d3.select("body").append("svg") | |
| .attr("width", width) | |
| .attr("height", height); | |
| var force = d3.layout.force() | |
| .size([width, height]) | |
| .charge(-400) | |
| .linkDistance(function(d) { return radius(d.source.size) + radius(d.target.size) + 20; }); | |
| var graph = { | |
| "nodes": [ | |
| {"index":0, "atom": "C", "size": 12}, | |
| {"index":1, "atom": "C", "size": 12}, | |
| {"index":2, "atom": "C", "size": 12}, | |
| {"index":3, "atom": "N", "size": 14}, | |
| {"index":4, "atom": "H", "size": 1}, | |
| {"index":5, "atom": "O", "size": 16}, | |
| {"index":6, "atom": "O", "size": 16}, | |
| {"index":7, "atom": "H", "size": 1}, | |
| {"index":8, "atom": "H", "size": 1}, | |
| {"index":9, "atom": "H", "size": 1}, | |
| {"index":10, "atom": "H", "size": 1}, | |
| {"index":11, "atom": "H", "size": 1}, | |
| {"index":12, "atom": "H", "size": 1} | |
| ], | |
| "links": [ | |
| {"source": 0, "target": 1, "bond": 1, "type":"work"}, | |
| {"source": 1, "target": 2, "bond": 1, "type":"work"}, | |
| {"source": 1, "target": 3, "bond": 1, "type":"hierarcy"}, | |
| {"source": 2, "target": 5, "bond": 2, "type":"work"}, | |
| {"source": 2, "target": 6, "bond": 1, "type":"work"}, | |
| {"source": 1, "target": 4, "bond": 1, "type":"hierarcy"}, | |
| {"source": 3, "target": 10, "bond": 1, "type":"work"}, | |
| {"source": 3, "target": 11, "bond": 1, "type":"work"}, | |
| {"source": 0, "target": 7, "bond": 1, "type":"hierarcy"}, | |
| {"source": 0, "target": 8, "bond": 1, "type":"work"}, | |
| {"source": 0, "target": 9, "bond": 1, "type":"work"}, | |
| {"source": 5, "target": 12, "bond": 1, "type":"work"} | |
| ] | |
| }; | |
| var neighbours = {}; | |
| d3.range(graph.nodes.length).forEach(function(i){neighbours[i] = {};}); | |
| graph.links.forEach(function(l){ | |
| neighbours[l.source][l.target] = l.type; | |
| neighbours[l.target][l.source] = l.type; | |
| }); | |
| force | |
| .nodes(graph.nodes) | |
| .links(graph.links) | |
| .on("tick", tick) | |
| .start(); | |
| var link = svg.selectAll(".link") | |
| .data(graph.links) | |
| .enter().append("g") | |
| .attr("class", "link"); | |
| link.append("line") | |
| .style("stroke-width", function(d) { return (d.bond * 2 - 1) * 2 + "px"; }); | |
| link.filter(function(d) { return d.bond > 1; }).append("line") | |
| .attr("class", "separator"); | |
| var node = svg.selectAll(".node") | |
| .data(graph.nodes) | |
| .enter().append("g") | |
| .attr("class", "node") | |
| .call(force.drag); | |
| node.append("circle") | |
| .attr("r", function(d) { return radius(d.size); }) | |
| .attr("index",function(d) { return d.index;}) | |
| .style("fill", "white") | |
| .on("mouseover", function (d) { | |
| d3.selectAll("circle").each(function(e){ | |
| var eindex = parseInt(this.attributes["index"].value); | |
| if (d.index === eindex){ | |
| this.style["stroke"] = "orange"; | |
| this.style["stroke-width"] = 5; | |
| } | |
| else if (e.index in neighbours[d.index]){ | |
| switch(neighbours[d.index][e.index]){ | |
| case "work" : { | |
| this.style["stroke"] = "lightblue"; | |
| this.style["stroke-width"] = 3; | |
| };break; | |
| case "hierarcy" : { | |
| this.style["stroke"] = "red" | |
| this.style["stroke-width"] = 3; | |
| }; break; | |
| } | |
| } else { | |
| this.style["stroke"] = "black"; | |
| } | |
| }); | |
| }) | |
| .on("mouseout", function () { | |
| d3.selectAll("circle").each(function(e){ | |
| this.style["stroke"] = "black"; | |
| this.style["stroke-width"] = 1; | |
| }) | |
| }); | |
| node.append("text") | |
| .attr("dy", ".35em") | |
| .attr("text-anchor", "middle") | |
| .text(function(d) { return d.index; }); | |
| function tick() { | |
| link.selectAll("line") | |
| .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("transform", function(d) { return "translate(" + d.x + "," + d.y + ")"; }); | |
| }; | |
| </script> | |
| </body> | |
| </html> |
