geoPath measures examples.
From D3 in Depth book by Peter Cook.
Last active
November 20, 2019 05:36
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geoPath measures examples
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| license: gpl-3.0 | |
| height: 650 | |
| border: no |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
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| <!DOCTYPE html> | |
| <meta charset="utf-8"> | |
| <head> | |
| <title>geoPath measures</title> | |
| </head> | |
| <style> | |
| body { | |
| font-family: "Helvetica Neue", Helvetica, sans-serif; | |
| font-size: 14px; | |
| color: #333; | |
| } | |
| #content .info { | |
| height: 20px; | |
| } | |
| #content .map path { | |
| fill: #aaa; | |
| stroke: #fff; | |
| } | |
| #content .bounding-box rect { | |
| fill: none; | |
| stroke: #333; | |
| stroke-dasharray: 2,1; | |
| } | |
| #content .centroid { | |
| display: none; | |
| } | |
| #content .centroid circle { | |
| fill: red; | |
| } | |
| </style> | |
| <body> | |
| <div id="content"> | |
| <div class="info">Hover over a country</div> | |
| <svg width="620px" height="600px"> | |
| <g class="map"></g> | |
| <g class="bounding-box"><rect></rect></g> | |
| <g class="centroid"><circle r="4"></circle></g> | |
| </svg> | |
| </div> | |
| <script src="https://cdnjs.cloudflare.com/ajax/libs/d3/4.9.1/d3.min.js"></script> | |
| <script> | |
| var projection = d3.geoMercator() | |
| .scale(400) | |
| .translate([200, 280]) | |
| .center([0, 5]); | |
| var geoGenerator = d3.geoPath() | |
| .projection(projection); | |
| function handleMouseover(d) { | |
| var pixelArea = geoGenerator.area(d); | |
| var bounds = geoGenerator.bounds(d); | |
| var centroid = geoGenerator.centroid(d); | |
| var measure = geoGenerator.measure(d); | |
| d3.select('#content .info') | |
| .text(d.properties.name + ' (path.area = ' + pixelArea.toFixed(1) + ' path.measure = ' + measure.toFixed(1) + ')'); | |
| d3.select('#content .bounding-box rect') | |
| .attr('x', bounds[0][0]) | |
| .attr('y', bounds[0][1]) | |
| .attr('width', bounds[1][0] - bounds[0][0]) | |
| .attr('height', bounds[1][1] - bounds[0][1]); | |
| d3.select('#content .centroid') | |
| .style('display', 'inline') | |
| .attr('transform', 'translate(' + centroid + ')'); | |
| } | |
| function update(geojson) { | |
| var u = d3.select('#content g.map') | |
| .selectAll('path') | |
| .data(geojson.features); | |
| u.enter() | |
| .append('path') | |
| .attr('d', geoGenerator) | |
| .on('mouseover', handleMouseover); | |
| } | |
| // REQUEST DATA | |
| d3.json('africa.json', function(err, json) { | |
| update(json) | |
| }) | |
| </script> | |
| </body> | |
| </html> |
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