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Last active March 24, 2017 20:31
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Force Layout - Point-Along-Path - State Diagram Animation
license: gpl-3.0
<!DOCTYPE html>
<meta charset="utf-8">
<style>
.node {
stroke: #fff;
stroke-width: 1.5px;
fill: #315de0
}
.link {
fill: none;
stroke: #bbb;
stroke-width: 5px;
}
.walking.circle {
fill: #c12105
}
</style>
<svg width="960" height="600"></svg>
<script src="https://d3js.org/d3.v4.min.js"></script>
<script>
var svg = d3.select("svg"),
width = +svg.attr("width"),
height = +svg.attr("height");
var color = d3.scaleOrdinal(d3.schemeCategory20);
var simulation = d3.forceSimulation()
.force("link", d3.forceLink().distance(200).strength(0.5))
.force("charge", d3.forceManyBody())
.force("center", d3.forceCenter(width / 2, height / 2));
d3.json("miserables.json", function(error, graph) {
if (error) throw error;
var nodes = graph.nodes,
nodeById = d3.map(nodes, function(d) {
return d.id;
}),
links = graph.links,
bilinks = [];
links.forEach(function(link) {
var s = link.source = nodeById.get(link.source),
t = link.target = nodeById.get(link.target),
i = {}; // intermediate node
nodes.push(i);
links.push({
source: s,
target: i
}, {
source: i,
target: t
});
bilinks.push([s, i, t]);
});
var link = svg.selectAll(".link")
.data(bilinks)
.enter().append("path")
.attr("class", "link");
svg.append("circle")
.attr("class", "walking circle")
.attr("r", 15);
var node = svg.selectAll(".node")
.data(nodes.filter(function(d) {
return d.id;
}))
.enter().append("circle")
.attr("class", "node")
.attr("r", 30)
.attr("fill", function(d) {
return color(d.group);
});
simulation
.nodes(nodes)
.on("tick", ticked);
simulation.force("link")
.links(links);
transition();
function ticked() {
link.attr("d", positionLink);
node.attr("transform", positionNode);
}
});
/////////////////////////////////////////////////////////////////////////
function positionLink(d) {
return "M" + d[0].x + "," + d[0].y +
"S" + d[1].x + "," + d[1].y +
" " + d[2].x + "," + d[2].y;
}
function positionNode(d) {
return "translate(" + d.x + "," + d.y + ")";
}
function dragstarted(d) {
if (!d3.event.active) simulation.alphaTarget(0.1).restart();
d.fx = d.x, d.fy = d.y;
}
function dragged(d) {
d.fx = d3.event.x, d.fy = d3.event.y;
}
function dragended(d) {
if (!d3.event.active) simulation.alphaTarget(0);
d.fx = null, d.fy = null;
}
function transition(node_index = 0) {
var node_count = svg.selectAll('path').nodes().length
if (node_index == node_count) {
node_index = 0;
}
svg.selectAll('.walking.circle').transition()
.duration(1000)
.attr("opacity", 1)
.attrTween("transform", translateAlong(svg.selectAll('path').nodes()[node_index]))
.on("end", function() {
transition(node_index + 1);
});
}
// Returns an attrTween for translating along the specified path element.
function translateAlong(path) {
var l = path.getTotalLength();
return function(d, i, a) {
return function(t) {
var p = path.getPointAtLength(t * l);
return "translate(" + p.x + "," + p.y + ")";
};
};
}
</script>
{
"nodes": [
{"id": "Myriel", "group": 1},
{"id": "Napoleon", "group": 1}
],
"links": [
{"source": "Napoleon", "target": "Myriel", "value": 1},
{"source": "Myriel", "target": "Napoleon", "value": 1}
]
}
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