So, what happens when you use the Delaunay triangulation to compute links between the centroids of the lower 48 United States of America? And then you simulate the whole thing as a force-directed graph? This, it turns out! Built with D3.js.
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March 11, 2025 02:58
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Force-Directed States of America
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| <!DOCTYPE html> | |
| <html> | |
| <head> | |
| <title>Force-Directed States of America</title> | |
| <script type="text/javascript" src="http://mbostock.github.com/d3/d3.js?1.26.0"></script> | |
| <script type="text/javascript" src="http://mbostock.github.com/d3/d3.geo.js?1.26.0"></script> | |
| <script type="text/javascript" src="http://mbostock.github.com/d3/d3.geom.js?1.26.0"></script> | |
| <script type="text/javascript" src="http://mbostock.github.com/d3/d3.layout.js?1.26.0"></script> | |
| <style type="text/css"> | |
| path { | |
| fill: #ddd; | |
| fill-opacity: .8; | |
| stroke: #fff; | |
| stroke-width: 1.5px; | |
| } | |
| line { | |
| stroke: #999; | |
| } | |
| </style> | |
| </head> | |
| <body> | |
| <script type="text/javascript"> | |
| var w = 960, | |
| h = 500; | |
| var path = d3.geo.path(), | |
| force = d3.layout.force().size([w, h]); | |
| var svg = d3.select("body").append("svg:svg") | |
| .attr("width", w) | |
| .attr("height", h); | |
| d3.json("readme.json", function(states) { | |
| var nodes = [], | |
| links = []; | |
| states.features.forEach(function(d, i) { | |
| if (d.id == "02" || d.id == "15" || d.id == "72") return; // lower 48 | |
| var centroid = path.centroid(d); | |
| centroid.x = centroid[0]; | |
| centroid.y = centroid[1]; | |
| centroid.feature = d; | |
| nodes.push(centroid); | |
| }); | |
| d3.geom.delaunay(nodes).forEach(function(d) { | |
| links.push(edge(d[0], d[1])); | |
| links.push(edge(d[1], d[2])); | |
| links.push(edge(d[2], d[0])); | |
| }); | |
| force | |
| .gravity(0) | |
| .nodes(nodes) | |
| .links(links) | |
| .linkDistance(function(d) { return d.distance; }) | |
| .start(); | |
| var link = svg.selectAll("line") | |
| .data(links) | |
| .enter().append("svg: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; }); | |
| var node = svg.selectAll("g") | |
| .data(nodes) | |
| .enter().append("svg:g") | |
| .attr("transform", function(d) { return "translate(" + -d.x + "," + -d.y + ")"; }) | |
| .call(force.drag) | |
| .append("svg:path") | |
| .attr("transform", function(d) { return "translate(" + d.x + "," + d.y + ")"; }) | |
| .attr("d", function(d) { return path(d.feature); }); | |
| force.on("tick", function(e) { | |
| 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("transform", function(d) { | |
| return "translate(" + d.x + "," + d.y + ")"; | |
| }); | |
| }); | |
| }); | |
| function edge(a, b) { | |
| var dx = a[0] - b[0], dy = a[1] - b[1]; | |
| return { | |
| source: a, | |
| target: b, | |
| distance: Math.sqrt(dx * dx + dy * dy) | |
| }; | |
| } | |
| </script> | |
| </body> | |
| </html> |
I also tried to replicate it with data of Peru but is not showing, I'm having problems to assign "d" attribute with path(d.feature) to nodes data.
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Hey there Mr Bostock, I tried to replicate this map with data of my own country and it's not working as it should, can you take a look at my code if it's not too much trouble?
Force Directed graph of Jamaica
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