D3 Examples - Test Velo'v Lyon Markers

Test Velo'v Lyon Markers
This is a simple setup of Leaflet (via Mapbox) with d3 to show dots on a map. This can serve as a base for many interesting geographically based visualizations
Nice overview of using d3 + Leaflet. I found this slightly simpler to use than Mike's classic post.
xxxxxxxxxx
 
<!DOCTYPE html>
<head>
  <meta charset="utf-8">
  <link 
        rel="stylesheet" 
        href="https://cdn.leafletjs.com/leaflet-0.7/leaflet.css"
    />
    <script src="https://d3js.org/d3.v3.min.js"></script>
​
    <script
        src="https://cdn.leafletjs.com/leaflet-0.7/leaflet.js">
    </script>
  <style>
    body { margin:0;position:fixed;top:0;right:0;bottom:0;left:0; }
    #map { 
      position:absolute; 
      width: 100%;
      height: 100%;
    }
  </style>
</head>
​
<body>
  <div id="map"></div>
  <script>
   
        
    //Setup our Leaflet map using Mapbox.js
    var map = L.map('map').setView([45.7531152, 4.827906], 12);
    mapLink = 
            '<a href="https://openstreetmap.org">OpenStreetMap</a>';
    L.tileLayer(
            'https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png', {
            attribution: '&copy; ' + mapLink + ' Contributors',
            maxZoom: 18,
            }).addTo(map);
    
    // Setup our svg layer that we can manipulate with d3
 //   var svg = d3.select(map.getPanes().overlayPane)
  //    .append("svg");
  //  var g = svg.append("g").attr("class", "leaflet-zoom-hide");
    
  //  function project(ll) {
      // our data came from csv, make it Leaflet friendly
   //   var a = [+ll.lat, +ll.lon]; 
      // convert it to pixel coordinates
   //   var point = map.latLngToLayerPoint(L.latLng(ll))
     // return point;
 //   }
 
    
    
    d3.json("data.json", function(err, data) {
     // var dots = g.selectAll("circle.dot")
      
        d3.json("data.json", function(err, geojson) {
      
      console.log("geojson data:", geojson);
      L.geoJson(geojson).addTo(map);
      
    })
      
   
      
 //     function render() {
        // We need to reposition our SVG and our containing group when the map
        // repositions via zoom or pan
        // https://github.com/zetter/voronoi-maps/blob/master/lib/voronoi_map.js
 //       var bounds = map.getBounds();
 //       var topLeft = map.latLngToLayerPoint(bounds.getNorthWest())
 //       var bottomRight = map.latLngToLayerPoint(bounds.getSouthEast())
  //      svg.style("width", map.getSize().x + "px")
  //        .style("height", map.getSize().y + "px")
  //        .style("left", topLeft.x + "px")
   //       .style("top", topLeft.y + "px");
   //     g.attr("transform", "translate(" + -topLeft.x + "," + -topLeft.y + ")");
​
        // We reproject our data with the updated projection from leaflet
    //    g.selectAll("circle.dot")
    //    .attr({
    //      cx: function(d) { return project(d).x},
      //    cy: function(d) { return project(d).y},
  //      })
​
 //     }
   
      
      // re-render our visualization whenever the view changes
      map.on("viewreset", function() {
    //    render()
      })
      map.on("move", function() {
   //     render()
      })
​
      // render our initial visualization
 //     render()
    })
   
​
  </script>
</body>
​
    