I would like to place pie charts on the node of a D3 force directed layout graph using D3.js. This is a common visualization in population genetics, see for example http://mathildasanthropologyblog.files.wordpress.com/2008/06/as3.jpg
I've started with a very basic graph plot:
<!DOCTYPE html>
<html lang="en">
<head>
<script type="text/javascript" src="d3/d3.v3.js"></script>
</head>
<body>
<script type="text/javascript">
graph = { "nodes":[{"proportions": [{"group": 1, "value": 1},
{"group": 2, "value": 2},
{"group": 3, "value": 3}]},
{"proportions": [{"group": 1, "value": 2},
{"group": 2, "value": 2},
{"group": 3, "value": 2}]}],
"links":[{"source": 0, "target": 1, "length": 500, "width": 1}]
}
var width = 960,
height = 500,
radius = 10,
color = d3.scale.category20c();
var svg = d3.select("body").append("svg")
.attr("width", width)
.attr("height", height);
var force = d3.layout.force()
.charge(-120)
.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");
var node = svg.selectAll(".node")
.data(graph.nodes)
.enter().append("circle")
.attr("class", "node")
.attr("r", radius)
.call(force.drag);
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; });
});
</script>
</body>
</html>
But when I try to replace the circle nodes with pie charts, the pie charts all end up stacked in the corner of the plot.
<!DOCTYPE html>
<html lang="en">
<head>
<script type="text/javascript" src="d3/d3.v3.js"></script>
</head>
<body>
<script type="text/javascript">
graph = { "nodes":[{"proportions": [{"group": 1, "value": 1},
{"group": 2, "value": 2},
{"group": 3, "value": 3}]},
{"proportions": [{"group": 1, "value": 2},
{"group": 2, "value": 2},
{"group": 3, "value": 2}]}],
"links":[{"source": 0, "target": 1, "length": 500, "width": 1}]
}
var width = 960,
height = 500,
radius = 10,
color = d3.scale.category20c();
var pie = d3.layout.pie()
.sort(null)
.value(function(d) { return d.value; });
var arc = d3.svg.arc()
.outerRadius(radius)
.innerRadius(0);
var svg = d3.select("body").append("svg")
.attr("width", width)
.attr("height", height);
var force = d3.layout.force()
.charge(-120)
.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");
var node = svg.selectAll(".node")
.data(graph.nodes)
.enter().append("g")
.attr("class", "node");
node.selectAll("path")
.data(function(d) {return pie(d.proportions); })
.enter().append("svg:path")
.attr("d", arc)
.style("fill", function(d) { return color(d.group); });;
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("x", function(d) { return d.x; })
.attr("y", function(d) { return d.y; });
});
</script>
</body>
</html>
Any assistance would be very appreciated!
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