Identity projection of map in d3.js

Answer to a question on stackoverflow. I used the answers to another question to centre and scale the map

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8" />

var vis = d3.select("#vis").append("svg")
          .attr("width", width).attr("height", height)

d3.json("po_2012_simplified.json", function(json) {

var projection = d3.geo.projection(function(x, y) { return [x, y];})
            .precision(0).scale(1).translate([0, 0]);

var path = d3.geo.path().projection(projection);

var bounds = path.bounds(json),
              scale  = .95 / Math.max((bounds[1][0] - bounds[0][0]) / width, 
                      (bounds[1][1] - bounds[0][1]) / height),
              transl = [(width - scale * (bounds[1][0] + bounds[0][0])) / 2, 
                      (height - scale * (bounds[1][1] + bounds[0][1])) / 2];

projection.scale(scale).translate(transl);

vis.selectAll("path").data(json.features).enter().append("path")
            .attr("d", path)
            .style("fill", "#D0D0D0")
            .style("stroke-width", "0.5px")
            .style("stroke", "black")
        });

</script>
  </body>
</html>

Modified http://d3js.org/d3.v3.min.js to a secure url

https://d3js.org/d3.v3.min.js