JavaScript/jQuery Vector Map - Custom Projection

This demo illustrates how to implement a custom projection. To do it, set the aspectRatio, to, and from properties. The Wagner-VI projection is used in this example.

www.wikipedia.org

Backend API

$(() => { const RADIANS = Math.PI / 180; const WAGNER_6_P_LAT = Math.PI / Math.sqrt(3); const WAGNER_6_U_LAT = 2 / Math.sqrt(3) - 0.1; const customProjection = { aspectRatio: 2, to(coordinates) { const x = coordinates[0] * RADIANS; const y = Math.min(Math.max(coordinates[1] * RADIANS, -WAGNER_6_P_LAT), +WAGNER_6_P_LAT); const t = y / Math.PI; return [ (x / Math.PI) * Math.sqrt(1 - 3 * t * t), (y * 2) / Math.PI, ]; }, from(coordinates) { const x = coordinates[0]; const y = Math.min(Math.max(coordinates[1], -WAGNER_6_U_LAT), +WAGNER_6_U_LAT); const t = y / 2; return [ (x * Math.PI) / Math.sqrt(1 - 3 * t * t) / RADIANS, (y * Math.PI) / 2 / RADIANS, ]; }, }; $('#vector-map').dxVectorMap({ projection: customProjection, title: 'Wagner VI projection', export: { enabled: true, }, layers: [{ dataSource: DevExpress.viz.map.sources.world, }, { color: '#aaa', borderWidth: 1, hoverEnabled: false, dataSource: coordLinesData, }], }); });

<!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml" lang="en"> <head> <title>DevExtreme Demo</title> <meta http-equiv="X-UA-Compatible" content="IE=edge" /> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=5.0" /> <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script> <script>window.jQuery || document.write(decodeURIComponent('%3Cscript src="js/jquery.min.js"%3E%3C/script%3E'))</script> <link rel="stylesheet" type="text/css" href="https://cdn3.devexpress.com/jslib/25.1.6/css/dx.light.css" /> <script src="js/dx.all.js?v=25.1.6"></script> <script src="https://cdn3.devexpress.com/jslib/25.1.6/js/vectormap-data/world.js"></script> <script src="https://cdn3.devexpress.com/jslib/25.1.6/js/vectormap-data/africa.js"></script> <script src="https://cdn3.devexpress.com/jslib/25.1.6/js/vectormap-data/canada.js"></script> <script src="https://cdn3.devexpress.com/jslib/25.1.6/js/vectormap-data/eurasia.js"></script> <script src="https://cdn3.devexpress.com/jslib/25.1.6/js/vectormap-data/europe.js"></script> <script src="https://cdn3.devexpress.com/jslib/25.1.6/js/vectormap-data/usa.js"></script> <script src="data.js"></script> <link rel="stylesheet" type="text/css" href="styles.css" /> <script src="index.js"></script> </head> <body class="dx-viewport"> <div class="demo-container"> <div id="vector-map"></div> </div> </body> </html>

#vector-map { height: 400px; }