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leaflet-canvaslayer-field

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A set of layers using canvas to draw ASCIIGrid or GeoTIFF files. This includes a basic raster layer (*ScalaField*) and an animated layer for vector fields, such as wind or currents (*VectorFieldAnim*)

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<!DOCTYPE html> <html> <head> <title>VectorFieldAnim / ColorBar</title> <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no" /> <link rel="stylesheet" href="//unpkg.com/leaflet@1.2.0/dist/leaflet.css" /> <link rel="stylesheet" href="examples.css" /> <link href="https://fonts.googleapis.com/css?family=Roboto:100,400" rel="stylesheet"> <style> .leaflet-control-colorBar-title { font-family: 'Roboto', sans-serif; font-weight: 100; font-size: large; } </style> </head> <body> <h1 class="title mapTitle">VectorFieldAnim and ColorBar</h1> <div id="map"></div> <!-- CDN --> <script src="//d3js.org/d3.v4.min.js"></script> <script src="//npmcdn.com/leaflet@1.2.0/dist/leaflet.js"></script> <script src="//cdnjs.cloudflare.com/ajax/libs/chroma-js/1.3.0/chroma.min.js"></script> <!-- Plugin --> <script src="dist/leaflet.canvaslayer.field.js"></script> <script> let map = L.map("map"); let url = 'https://cartodb-basemaps-{s}.global.ssl.fastly.net/dark_nolabels/{z}/{x}/{y}.png'; L.tileLayer(url, { attribution: 'OSM & Carto', subdomains: 'abcd', maxZoom: 19 }).addTo(map); /* Vectorfield animation with a colormap for magnitude + and associated colorBar */ d3.text('data/Cantabria_U.asc', function (u) { d3.text('data/Cantabria_V.asc', function (v) { let scaleFactor = 0.001; // to m/s let vf = L.VectorField.fromASCIIGrids(u, v, scaleFactor); var range = vf.range; var scale = chroma.scale('OrRd').domain(range); // Layer var layer = L.canvasLayer.vectorFieldAnim(vf, { paths: 2000, color: scale, velocityScale: 1 / 200 }).addTo(map); /* layer.setFilter(function(vector) { // it might be needed to reduce the number of paths if (vector) { return vector.magnitude() > 1; } return false; }); */ map.fitBounds(layer.getBounds()); // Simple colorbar var bar = L.control.colorBar(scale, range, { title: 'Currents surface velocity (m/s)', units: 'm/s', steps: 100, decimals: 1, width: 350, height: 20, position: 'bottomright', background: '#000', textColor: 'white', labels: [0, 0.5, 1.0, 1.5, 2.0], labelFontSize: 9 }).addTo(map); // info layer.on('click', function (e) { if (e.value !== null) { let vector = e.value; let v = vector.magnitude().toFixed(2); let d = vector.directionTo().toFixed(0); let html = (`<span class="popupText">${v} m/s to ${d}&deg</span>`); let popup = L.popup() .setLatLng(e.latlng) .setContent(html) .openOn(map); } }); }); }); </script> </body> </html>