santiaago/pieChartData.csv

## piechart.html
<!DOCTYPE html>
<meta charset="utf-8">
<style>

body {
  font: 16px sans-serif;
}

.arc path {
  stroke: #fff;
}

</style>
<body>
<script src="http://d3js.org/d3.v3.min.js"></script>
<script>

var width = 480,
    height = 250,
    radius = Math.min(width, height) / 2;

var color = d3.scale.ordinal()
    .range(["#B9E397", "#D46A6A", "#7282AA"]);

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

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

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

d3.csv("pieChartData.csv", function(error, data) {

  data.forEach(function(d) {
    d.population = +d.population;
  });

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

  g.append("path")
      .attr("d", arc)
      .style("fill", function(d) { return color(d.data.sentiment); });

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

});

</script>

## pieChartData.csv

          
            sentiment
            population

            
              positive
              50

            
              negative
              20

            
              neutral
              30
	<!DOCTYPE html>
	<meta charset="utf-8">
	<style>

	body {
	font: 16px sans-serif;
	}

	.arc path {
	stroke: #fff;
	}

	</style>
	<body>
	<script src="http://d3js.org/d3.v3.min.js"></script>
	<script>

	var width = 480,
	height = 250,
	radius = Math.min(width, height) / 2;

	var color = d3.scale.ordinal()
	.range(["#B9E397", "#D46A6A", "#7282AA"]);

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

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

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

	d3.csv("pieChartData.csv", function(error, data) {

	data.forEach(function(d) {
	d.population = +d.population;
	});

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

	g.append("path")
	.attr("d", arc)
	.style("fill", function(d) { return color(d.data.sentiment); });

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

	});

	</script>