Flights by entity (Jan - Feb 2016 vs Jan - Feb 2015)

TODOs:

position labels for negative bars on the right side, see this SO post
highlight relevant underlying bar when hovering on y-axis label, see commented out stroke styling on bars

Data about percent change of flights movement by entity (Jan - Feb 2016 vs Jan - Feb 2015) from PRU website.

Inspired by Mike's Bar Chart with Negative Values.

<!DOCTYPE html>
<meta charset="utf-8">
<style>
 .bar--positive {
   fill: steelblue;
 }

.bar--negative {
   fill: darkorange;
 }

.xlabel, .axis text {
   font: 10px sans-serif;
 }

.axis path,
 .axis line {
   fill: none;
   stroke: #000;
   shape-rendering: crispEdges;
 }
 .tick line{
   opacity: 0.15;
 }

#tooltip {
   position: absolute;
   width: auto;
   height: auto;
   padding: 2px 2px;
   -webkit-border-radius: 3px;
   -moz-border-radius: 3px;
   border-radius: 3px;
   -webkit-box-shadow: 2px 2px 5px rgba(0, 0, 0, 0.4);
   -moz-box-shadow: 2px 2px 5px rgba(0, 0, 0, 0.4);
   box-shadow: 2px 2px 5px rgba(0, 0, 0, 0.4);
   pointer-events: none;
   background-color: #bbb;
   stroke-width: 0.5px;
 }

#tooltip.hidden {
   display: none;
 }

#tooltip p {
   margin: 0 0 0 0;
   padding: 2px 2px;
   font-family: sans-serif;
   font-size: 11px;
 }

.hidden{
   display: none;
 }

</style>
<body>
  <div id="tooltip" class="hidden">
    <p id="info"></p>
  </div>
  <script src="//d3js.org/d3.v3.min.js"></script>
  <script>

var margin = {top: 20, right: 30, bottom: 40, left: 30},
       width = 960 - margin.left - margin.right,
       height = 500 - margin.top - margin.bottom;

var formatPercent = d3.format("+,%");
   var x = d3.scale.linear()
             .range([0, width]);

var y = d3.scale.ordinal()
             .rangeRoundBands([0, height], 0.1);

var xAxis = d3.svg.axis()
                 .scale(x)
                 .orient("bottom")
                 .innerTickSize(-height)
                 .tickPadding(8)
                 .tickFormat(formatPercent);

var yAxis = d3.svg.axis()
                 .scale(y)
                 .orient("left")
                 .tickSize(0)
                 .tickPadding(6);

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 + ")");

var tooltip = d3.select("#tooltip").classed("hidden", true);
   var info = d3.select("#info");
   svg.on("mousemove", function () {
     // update tooltip position
     tooltip.style("top", (event.pageY + 8) + "px").style("left", (event.pageX + 8) + "px");
     return true;
   });

d3.tsv("ert_flt_ansp.tsv", type, function(error, data) {
     x.domain(d3.extent(data, function(d) { return d.value; })).nice();
     y.domain(data.map(function(d) { return d.name; }));

svg.selectAll(".bar")
        .data(data)
        .enter().append("rect")
        .attr("class", function(d) { return "bar bar--" + (d.value < 0 ? "negative" : "positive"); })
        .attr("x", function(d) { return x(Math.min(0, d.value)); })
        .attr("y", function(d) { return y(d.name); })
        .attr("width", function(d) { return Math.abs(x(d.value) - x(0)); })
        .attr("height", y.rangeBand())
        .on("mouseover", function (d, i) {
          // d3.select(this).style({'stroke': '#F00'});
          // https://stackoverflow.com/questions/17917072/#answer-17917341
          tooltip.classed("hidden", false);
          info.text(d.name + ": " + d.prc_change + "%");
        })
        .on("mouseout", function () {
          // this.style.stroke = "none";
          tooltip.classed("hidden", true);
        });

svg.append("text")      // text label for the x axis
        .attr("class", "xlabel")
        .attr("x", width / 2 )
        .attr("y",  height + margin.bottom - 4)
        .style("text-anchor", "bottom")
        .text("% change (Jan - Feb 2016 vs Jan - Feb 2015)");

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

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

// TODO: position y label on the right for negative values
     svg.selectAll(".y.axis g.tick text")
        .data(data)
       //   .attr("x", width / 2 )
        .on("mouseover", function (d) {
          if (d.value < 0) {
            d3.select(this).style({"cursor": "default"});
            tooltip.classed("hidden", false);
            info.text(d.name + ": " + d.prc_change + "%");
          }
        })
        .on("mouseout", function () {
          tooltip.classed("hidden", true);
        })
       ;
   });

function type(d) {
     d.value = +d.prc_change/100;
     d.name = d.entity;
     return d;
   }

</script>

https://d3js.org/d3.v3.min.js