title: d3 mapping with zoom but strange pan limit beavure
body: <p>I'm making a series a maps of Italy and I started with this template: <a href="http://techslides.com/responsive-d3-map-with-zoom-and-pan-limits/" rel="nofollow">http://techslides.com/responsive-d3-map-with-zoom-and-pan-limits/</a></p>
  
  <p>The problem is that when a zoom into my map <a href="http://www.danielepennati.com/prove/mapping/ita_pop_den.html" rel="nofollow">http://www.danielepennati.com/prove/mapping/ita_pop_den.html</a> the pan is limited and I can zoom in the eastern part of the map</p>
  
  <p>the projection is defined like this: </p>
  
  <pre><code>var projection = d3.geo.mercator()
        .scale(3300)
        .center([12, 42])
        .translate([width / 2, height / 2]);
  </code></pre>
  
  <p>and the zoom:</p>
  
  <pre><code>var zoom = d3.behavior.zoom()
        .scaleExtent([1, 13])
        .on("zoom", move);
  function move() {
  
      var t = d3.event.translate;
      var s = d3.event.scale;  
      var h = height / 3;
  
      t[0] = Math.min(width / 2 * (s - 1), Math.max(width / 2 * (1 - s), t[0]));
      t[1] = Math.min(height / 2 * (s - 1) + h * s, Math.max(height / 2 * (1 - s) - h * s, t[1]));
  
      zoom.translate(t);
      g.style("stroke-width", 1 / s).attr("transform", "translate(" + t + ")scale(" + s + ")");
    }
  </code></pre>
  
  <p>Could you help me?<br>
  this is my first attempt with d3 mapping :-)<br>
  thanks<br>
  daniele</p>