square pie chart ( d3.js )

<!DOCTYPE html>
<html>
<head>   
  <meta charset="utf-8">
  <script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.6/d3.min.js"></script>
</head>
<body>

var arc = d3.svg.arc()
    .outerRadius(radius - 10)
    .innerRadius(0);

var data = [ 
 ["de",1968],
 ["la",1407],
 ["el",1246],
 ["en",1066],
 ["a",1044],
 ["y",687]
/* ["un",580],
   ["del",504],
   ["por",471],
   ["los",437] */
];

var pie = d3.layout.pie()
    .sort(null)
    .value(function(d) { return d[1]; });

var svg = d3.select("body").append("svg")
    .attr("width", width)
    .attr("height", height)
  .append("g")
    .attr("transform", "translate(" + width / 2 + "," + height / 2 + ")");

var g = svg.selectAll(".arc")
      .data(pie(data))
    .enter().append("g")
      .attr("class", "arc");

g.append("path")
 .attr("d", arc)
 .attr("stroke", "#fff")
 .style("fill", function(d,i) { return c10(i); });

g.append("text")
 .attr("transform", function(d) { return "translate(" + arc.centroid(d) + ")"; })
 .attr("dy", ".35em")
 .style("text-anchor", "middle")
 .attr("fill","white")
 .text( function(d) {return d.data[0];} );

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

https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.6/d3.min.js