map

<!DOCTYPE html>
<head>
  <meta charset="utf-8">
  <script src="https://d3js.org/d3.v4.min.js"></script>
  <script src="https://d3js.org/d3-scale-chromatic.v1.min.js"></script>
  <style>
    body { margin:0;position:fixed;top:0;right:0;bottom:0;left:0; }
  </style>
</head>

<body>
  <script>
		var width = 700,
  		  height = 580;

var svg = d3.select( "body" )
  		.append( "svg" )
		  .attr( "width", width )
		  .attr( "height", height );
    
    
		
    
    d3.geoConicConformal().center([2.454071, 46.279229]).scale(2800);
    
    var path = d3.geoPath() // d3.geo.path avec d3 version 3
                 .projection(d3.geoConicConformal().center([2.454071, 46.279229]).scale(2800));
    
    d3.csv("GrippeFrance2014.csv", function(data) {
    
   	var max=d3.max(data, function(d){return +d.somme2014});
      
		d3.json("regions.json", function(json) {
      
    for (var i = 0; i < data.length; i++) {

// Grab State Name
      var region = data[i].region;

// Grab data value 
      var dataValue = data[i].somme2014;

// Find the corresponding state inside the GeoJSON
      for (var j = 0; j < json.features.length; j++)  {
        var jsonRegion = json.features[j].properties.nom;

if (region == jsonRegion) {

json.features[j].properties.grippe= dataValue;

// Stop looking through the JSON
        break;
        }
      }}
    
      
	    svg.selectAll("path")
           .data(json.features)
           .enter()
           .append("path")
           .attr("d", path)
      		 .style("stroke", "#fff")
					 .style("stroke-width", "1")
      		 .style("fill",function(d){return d3.interpolateReds(d.properties.grippe/max)})
    })
    })
  					  			
	            
  </script>
</body>

https://d3js.org/d3.v4.min.js

https://d3js.org/d3-scale-chromatic.v1.min.js