MSAN 622, Project 1 (Part 2) - 2012 U.S. Presidential Elections - Voting trends

MSAN 622, Project 1 Piyush Bhargava

Part 1 - SF per capita income trend - Source dataset

Part 2 - U.S. Presidential Elections 2012 -

The Data comes from Federal Election Commission's website:Federal Elections 2012: Election Results for the U.S. President
A hand drawn prototype sketch of a visualization

Three dimensions/columns visualized are:

Number of voters - Continuous data - represented on Y-axis
US States - Categorical data - represented on X-axis
Candidates (Obama/Romney/Others) - Categorical data - facet in legend

The chart

Requirements:

one categorical column (used as a facet in the legend) - 'Candidates', one continuous - 'Number of Voters', and an additional third column that can be any data type - 'States' .
Labeled Axes - in chart
A legend - in chart

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

body {
  font: 10px sans-serif;
}
.title {
  font: bold 20px "Helvetica Neue", Helvetica, Arial, sans-serif;
}
.axis path,
.axis line {
  fill: none;
  stroke: #000;
  shape-rendering: crispEdges;
}

.bar {
  fill: steelblue;
}

.x.axis path {
  display: none;
}

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

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

var x = d3.scale.ordinal()
    .rangeRoundBands([0, width], .1);

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

var color = d3.scale.ordinal()
    .range(["#5b3d5b", "#7fc97f"," #ff8c00"]);

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

var yAxis = d3.svg.axis()
    .scale(y)
    .orient("left")
    .tickFormat(d3.format(".2s"));

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("https://piyushbhargava7.github.io/data_1.csv", function(error, data) {
  if (error) throw error;

color.domain(d3.keys(data[0]).filter(function(key) { return key !== "State"; }));

data.forEach(function(d) {
    var y0 = 0;
    d.candidates = color.domain().map(function(name) { return {name: name, y0: y0, y1: y0 += +d[name]}; });
    d.total = d.candidates[d.candidates.length - 1].y1;
  });

data.sort(function(a, b) { return b.total - a.total; });

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

svg.append("g")
      .attr("class", "x axis")
      .attr("transform", "translate(0," + height + ")")
      .call(xAxis)
    .append("text")
      .attr("x", 850)
      .attr("dy", "2.25em")
      .style("text-anchor", "end")
      .text("States");
      
  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")
      .text("Number of Voters");
  
  svg.append("text")
      .attr("class", "title")
      .attr("x", 300)
      .attr("y", 15)
      .text("2012 US Presidential Election Voting trends");
      
  var state = svg.selectAll(".state")
      .data(data)
    .enter().append("g")
      .attr("class", "g")
      .attr("transform", function(d) { return "translate(" + x(d.State) + ",0)"; });

state.selectAll("rect")
      .data(function(d) { return d.candidates; })
    .enter().append("rect")
      .attr("width", x.rangeBand())
      .attr("y", function(d) { return y(d.y1); })
      .attr("height", function(d) { return y(d.y0) - y(d.y1); })
      .style("fill", function(d) { return color(d.name); });

var legend = svg.selectAll(".legend")
      .data(color.domain().slice().reverse())
    .enter().append("g")
      .attr("class", "legend")
      .attr("transform", function(d, i) { return "translate(0," + i * 20 + ")"; });

legend.append("rect")
      .attr("x", width - 18)
      .attr("width", 18)
      .attr("height", 18)
      .style("fill", color);

legend.append("text")
      .attr("x", width - 24)
      .attr("y", 9)
      .attr("dy", ".35em")
      .style("text-anchor", "end")
      .text(function(d) { return d; });

});

</script>

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