 c:30, d:8, e:12}

// set the color scale
var color = d3.scaleOrdinal()
  .domain(data)
  .range(["#98abc5", "#8a89a6", "#7b6888", "#6b486b", "#a05d56"])

// Compute the position of each group on the pie:
var pie = d3.pie()
  .value(function(d) {return d.value; })
var data_ready = pie(d3.entries(data))

// Build the pie chart: Basically, each part of the pie is a path that we build using the arc function.
svg
  .selectAll('whatever')
  .data(data_ready)
  .enter()
  .append('path')
  .attr('d', d3.arc()
   