Map visualisation

<!DOCTYPE html>
<head>
  <meta charset="utf-8">
  <script src="https://d3js.org/d3.v4.min.js"></script>
  <style>
  
    body { margin:0;position:fixed;top:0;right:0;bottom:0;left:0; }
   div.tooltip {
        color: #9b9b9b;
      background-color: #fff;
       padding: .5em;
       text-shadow: #bcbcbc 0 1px 0;
        border-radius: 2px;
        opacity: 0.9;
        position: absolute;
    }

</style>
</head>

</div>
  <script>
		var width = 980,
  		  height = 800;
    
		var color = d3.scaleLinear()
    .range([d3.rgb("#e0efff"), d3.rgb('#a800ea')]);
    
    
    var tooltip = d3.select('body').append('div')
            .attr('class', 'hidden tooltip');
    
		var svg = d3.select( "body" )
  		.append( "svg" )
		  .attr( "width", width )
		  .attr( "height", height );

var projection = d3.geoConicConformal().center([2.454071, 46.279229]).scale(2800);
    var path = d3.geoPath() 
                 .projection(projection);
    
   
    d3.csv("GrippeFrance2014.csv", function(data) {
      color.domain([0,400]);

d3.json("regions.json", function(json) {
  
      for (var i = 0; i < data.length; i++) {
 					for(var j=0; j<json.features.length; j++) {
          if(data[i].region == json.features[j].properties.nom) {
        		var dataValue = parseFloat(data[i].somme2014);
          	json.features[j].properties.value= dataValue;
      	}
        }
      }

svg.selectAll("path")
         .data(json.features)
         .enter()
         .append("path")
         .attr("d", path)
         //.style("stroke", "#ffffff")
         //.style("stroke-width", "1")
         .style("fill", function(d) {
              var value = d.properties.value;
             return color(value);});
      ;
      
    
      svg.selectAll("path")
      	 .on('mousemove', function(d) {
                    var mouse = d3.mouse(svg.node()).map(function(d) {
                        return parseInt(d);
                    });
                    tooltip.classed('hidden', false)
                        	 .attr('style', 'left:' + (mouse[0] + 15) + 
                                 'px; top:' + (mouse[1] - 35) + 'px')
                       	   .html(d.properties.nom + " : " + d.properties.value);
                })
       
        
    });
});

</script>
</body>

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