I am using a lat&long coordinates I receive in input by the user to visualize a map with leaflet.js. As I do that, I compute a heatmap in the background (e.g. population density map in the 5km-wide area surrounding the chosen coordinates).
How do I overlay the heatmap to my map?
Here's what I got so far: an html file to generate the map, and a .js file created by my background computations where I store the chosen coordinates, some polygons or interest, and where I hope to store/point-to the raster map I generate for that region.
<!DOCTYPE html>
<html>
<head>
<title>Testmap</title>
<script src="http://d3js.org/d3.v3.min.js"></script>
<script src="http://d3js.org/topojson.v1.min.js"></script>
<style>
@import url(http://cdn.leafletjs.com/leaflet-0.6.1/leaflet.css);
#overlay{
fill:None;
stroke:#ff00ff;
stroke-width:4px;
}
</style>
</head>
<body>
<div id="map" style="width: 960px; height: 600px"></div>
<script src="http://cdn.leafletjs.com/leaflet-0.6.1/leaflet.js"
</script>
<script src="rois.js"></script>
<script>
var toolserver = L.tileLayer('http://{s}.www.toolserver.org/tiles/bw-mapnik/{z}/{x}/{y}.png');
var stamen = L.tileLayer('http://{s}.tile.stamen.com/toner/{z}/{x}/{y}.png', {attribution: 'myMap'}).addTo(map);
var baseLayers = {"stamen": stamen, "toolserver-mapnik":toolserver};
var geojson = L.geoJson(rois, {
onEachFeature: onEachFeature
}).addTo(map)
var overlays = {
"geoJson": geojson
};
function onEachFeature(feature, layer){
if (feature.properties) {
layer.bindPopup("<b>" + feature.properties.street + "</b> is " + feature.properties.length + "km long.");
}
}
var svgContainer= d3.select(map.getPanes().overlayPane).append("svg");
var group= svgContainer.append("g").attr("class", "leaflet-zoom-hide");
var path = d3.geo.path().projection(project);
function project(point) {
var latlng = new L.LatLng(point[1], point[0]);
var layerPoint = map.latLngToLayerPoint(latlng);
return [layerPoint.x, layerPoint.y];
}
</script>
</body>
</html>
The file rois.js is generated by my program in the background and contains the chosen coordinates and some polygons to be drawn on the map. I would like to understand how I can include raster information in here.
var map = L.map('map').setView([52.500,13.385], 13);
var rois = [{
"type": "FeatureCollection",
"features": [{
"type": "Feature",
"id": 1,
"geometry": {
"type": "Polygon",
"coordinates": [[[13.370, 52.491], [13.400, 52.491], [13.400, 52.509],[13.370, 52.509],[13.370, 52.491]]]
}
},
{ "type": "Feature",
"id": 2,
"geometry": {
"type": "Polygon",
"coordinates": [[[13.415, 52.496], [13.425, 52.505], [13.435, 52.496], [13.415, 52.496]]]
}
}]
}];
Thanks FP
See the Leaflet plugins for generating heatmaps (and update your leaflet version, 0.6.x is more than three years old).