var map = L.map('map').setView([39.9897471840457, -75.13893127441406], 11) // Add basemap L.tileLayer('http://{s}.tiles.wmflabs.org/bw-mapnik/{z}/{x}/{y}.png', { maxZoom: 18, attribution: '© OpenStreetMap' }).addTo(map) // Add GeoJSON $.getJSON('../basic/crimes_by_district.geojson', function (geojson) { var choroplethLayer = L.choropleth(geojson, { valueProperty: 'incidents', scale: ['white', 'red'], steps: 5, mode: 'q', style: { color: '#fff', weight: 2, fillOpacity: 0.8 }, onEachFeature: function (feature, layer) { layer.bindPopup('District ' + feature.properties.dist_num + '
' + feature.properties.incidents.toLocaleString() + ' incidents') } }).addTo(map) // Add legend (don't forget to add the CSS from index.html) var legend = L.control({ position: 'bottomright' }) legend.onAdd = function (map) { var div = L.DomUtil.create('div', 'info legend') var limits = choroplethLayer.options.limits var colors = choroplethLayer.options.colors var labels = [] // Add min & max div.innerHTML = '
' + limits[0] + '
\
' + limits[limits.length - 1] + '
' limits.forEach(function (limit, index) { labels.push('
  • ') }) div.innerHTML += '' return div } legend.addTo(map) })