Waterfall Chart

A recreation of the waterfall chart example in Wikipedia. This type of chart is popularized by McKinsey & Company in explaining the cumulative impact of various factors on some quantitative value.

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

.bar.total rect {
  fill: steelblue;
}

.bar.positive rect {
  fill: darkolivegreen;
}
.bar.negative rect {
  fill: crimson;
}

.bar line.connector {
  stroke: grey;
  stroke-dasharray: 3;
}

.bar text {
  fill: white;
  font: 12px sans-serif;
  text-anchor: middle;
}

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

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

</style>
<svg class="chart"></svg>
<script src="https://d3js.org/d3.v3.min.js"></script>
<script>
var margin = {top: 20, right: 30, bottom: 30, left: 40},
    width = 960 - margin.left - margin.right,
    height = 500 - margin.top - margin.bottom,
    padding = 0.3;

var x = d3.scale.ordinal()
    .rangeRoundBands([0, width], padding);

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

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

var yAxis = d3.svg.axis()
    .scale(y)
    .orient("left")
    .tickFormat(function(d) { return dollarFormatter(d); });

var chart = d3.select(".chart")
    .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("data.csv", type, function(error, data) {

// Transform data (i.e., finding cumulative values and total) for easier charting
  var cumulative = 0;
  for (var i = 0; i < data.length; i++) {
    data[i].start = cumulative;
    cumulative += data[i].value;
    data[i].end = cumulative;

data[i].class = ( data[i].value >= 0 ) ? 'positive' : 'negative'
  }
  data.push({
    name: 'Total',
    end: cumulative,
    start: 0,
    class: 'total'
  });

x.domain(data.map(function(d) { return d.name; }));
  y.domain([0, d3.max(data, function(d) { return d.end; })]);

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

chart.append("g")
      .attr("class", "y axis")
      .call(yAxis);

var bar = chart.selectAll(".bar")
      .data(data)
    .enter().append("g")
      .attr("class", function(d) { return "bar " + d.class })
      .attr("transform", function(d) { return "translate(" + x(d.name) + ",0)"; });

bar.append("rect")
      .attr("y", function(d) { return y( Math.max(d.start, d.end) ); })
      .attr("height", function(d) { return Math.abs( y(d.start) - y(d.end) ); })
      .attr("width", x.rangeBand());

bar.append("text")
      .attr("x", x.rangeBand() / 2)
      .attr("y", function(d) { return y(d.end) + 5; })
      .attr("dy", function(d) { return ((d.class=='negative') ? '-' : '') + ".75em" })
      .text(function(d) { return dollarFormatter(d.end - d.start);});

bar.filter(function(d) { return d.class != "total" }).append("line")
      .attr("class", "connector")
      .attr("x1", x.rangeBand() + 5 )
      .attr("y1", function(d) { return y(d.end) } )
      .attr("x2", x.rangeBand() / ( 1 - padding) - 5 )
      .attr("y2", function(d) { return y(d.end) } )
});

function type(d) {
  d.value = +d.value;
  return d;
}

function dollarFormatter(n) {
  n = Math.round(n);
  var result = n;
  if (Math.abs(n) > 1000) {
    result = Math.round(n/1000) + 'K';
  }
  return '$' + result;
}

</script>

Modified http://d3js.org/d3.v3.min.js to a secure url

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