Avg Price Histories (force_labels)

This line chart is constructed from a CSV in the "Multi-Series Format" from Bureau of Labor Statistics Consumer Price Index data. The chart employs conventional margins and a number of D3 features:

d3.csv - load and parse data
d3.time.format - parse dates
d3.time.scale - x-position encoding
d3.scale.linear - y-position encoding
d3.hcl - a perceptual color space
d3.extent, d3.min and d3.max - compute domains
d3.svg.axis - display axes
d3.svg.line - display line shape

The chart also uses a couple functions from Underscore.js:

_.pluck - to extra a list of values from an array of objects
_.each
_.map

<!DOCTYPE html>
<title>Average Price Histories</title>
<meta charset="utf-8">
<style>
body {
  font: 10px sans-serif;
}

.axis path,
.axis line {
  fill: none;
  stroke: #000;
  shape-rendering: crispEdges;
}

.x.axis path {
  display: none;
}

.line {
  fill: none;
  stroke: steelblue;
  stroke-width: 1.5px;
  -webkit-transition: opacity 0.3s;
  -moz-transition: opacity 0.3s;
  -o-transition: opacity 0.3s;
  transition: opacity 0.3s;
}

path.invisible {
  fill: none;
  stroke: rgba(0,0,0,0);
  stroke-width: 8px;
}

text.label {
  font-size: 12px;
  font-weight: bold;
}

</style>

<body></body>
<script type="text/javascript">
var margin = {top: 20, right: 220, bottom: 30, left: 50},
    width = 1000 - margin.left - margin.right,
    height = 500 - margin.top - margin.bottom;

var format = d3.time.format("%b %Y");

var start = format.parse("Jan 1984");
var end = format.parse("Aug 2012");
var range = d3.time.months(start,end);

var x = d3.time.scale()
    .range([0,width])
    .domain([start,end]);

var y = d3.scale.linear()
    .range([height, 0]);

var color = function(i) {
  return d3.hcl(48*i,95,45).toString();
};

var xAxis = d3.svg.axis()
    .scale(x)
    .orient("bottom");

var yAxis = d3.svg.axis()
    .scale(y)
    .orient("left");

var line = d3.svg.line()
    .interpolate("basis")
    .defined(function(d) { return d != null; })
    .x(function(d,i) { return x(range[i]); })
    .y(function(d) { return y(d); });

var svg = d3.select("body").append("svg")
    .attr("width", width + margin.left + margin.right)
    .attr("height", height + margin.top + margin.bottom)
  .append("g")
    .attr("transform", "translate(" + margin.left + "," + margin.top + ")");

d3.csv("average-prices.csv", function(raw) {
  var data = [];
  var goods = _(raw).pluck("Name");

_(raw).each(function(series) {
    var value = {};
    data.push({
      id: series["Series ID"],
      name: series["Name"],
      values: _(range).map(function(month) {
                return parseFloat(series[format(month)]) || null;
              })
    });
  });

var values = _(data).chain().pluck('values').flatten().value();

y.domain([
    0,
    d3.max(values)
  ]);

svg.append("g")
      .attr("class", "x axis")
      .attr("transform", "translate(0," + height + ")")
      .call(xAxis);

svg.append("g")
      .attr("class", "y axis")
      .call(yAxis)
    .append("text")
      .attr("transform", "rotate(-90)")
      .attr("y", 6)
      .attr("dy", ".71em")
      .style("text-anchor", "end")
      .style("font-weight", "bold")
      .text("Average Price");

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

series.append("path")
      .attr("class", "line")
      .attr("d", function(d) { return line(d.values); })
      .style("stroke", function(d,i) { return color(i); });

series.append("path")
      .attr("class", "invisible hover")
      .attr("d", function(d) { return line(d.values); });

////// BEGIN FORCE_LABELS//////
  labelForce = d3.force_labels()
      .linkDistance(0.0)
      .gravity(0)
      .charge(-15)
      .on("tick",function() { 
        d3.selectAll(".label").attr("transform",function(d) {
           d.labelPos.x = x(end)+10;  // Fix the x value
           return "translate("+d.labelPos.x+" "+d.labelPos.y+")"})
      })
  
  labels = series.append("g")
      .attr("class","labels")
      .datum(function(d) { return {name: d.name, value: d.values[d.values.length - 1]}; })

// We need a small SVG object at the line-end to act as the anchor in labelforce.update
  labels.append("circle")
      .attr("class","anchor line")
      .attr("cx",function(d) { return x(end)})
      .attr("cy",function(d) { return y(d.value)})
      .attr("r",2)
      .style("fill", function(d,i) { return color(i); })
      .style("stroke", function(d,i) { return color(i); })
      .call(labelForce.update)  // Define this set to be the anchorNodes

// Add labels, that will be positioned by the on("tick") in labelForce
  labels.append("text")
    .attr("class","label")
    .attr("x", 3)
    .attr("dy", ".35em")
    .style("fill", function(d,i) { return color(i); })
    .text(function(d) { return d.name; });
  ////// END FORCE LABELS //////
   
  series.selectAll(".hover")
      .on("mouseover", function(d,i) {
        d3.selectAll(".line")
          .style("opacity", 0.12)
          .filter(function(p) { return p.name == d.name; })
          .style("opacity", 1)
          .style("stroke-width", 2.5);
        d3.selectAll(".series text")
          .style("opacity", 0)
          .filter(function(p) { return p.name == d.name; })
          .style("opacity", 1);
      })
      .on("mouseout", function(d,i) {
        d3.selectAll(".line")
          .style("opacity", 1)
          .style("stroke-width", null);
        d3.selectAll(".series text")
          .style("opacity", 1);
      });
});
</script>

Modified http://mbostock.github.com/d3/d3.v2.js to a secure url

Updated missing url https://raw.github.com/d3/d3-plugins/master/force_labels/force_labels.js to https://cdn.jsdelivr.net/gh/d3/d3-plugins/force_labels/force_labels.js

Modified http://documentcloud.github.com/underscore/underscore.js to a secure url

https://mbostock.github.com/d3/d3.v2.js

https://raw.github.com/d3/d3-plugins/master/force_labels/force_labels.js

https://documentcloud.github.com/underscore/underscore.js