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 hidden or 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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