Simple(?) Horizontal Stacked Bar Charts

_.md

[ Launch: Simple(?) Stacked Bar Charts ] 4966973 by gelicia
[ Launch: Simple(?) Stacked Bar Charts ] 4945496 by gelicia

config.json

{"description":"Simple(?) Horizontal Stacked Bar Charts","endpoint":"","display":"svg","public":true,"require":[],"fileconfigs":{"inlet.js":{"default":true,"vim":false,"emacs":false,"fontSize":12},"_.md":{"default":true,"vim":false,"emacs":false,"fontSize":12},"config.json":{"default":true,"vim":false,"emacs":false,"fontSize":12}},"fullscreen":false,"play":false,"loop":false,"restart":false,"autoinit":true,"pause":true,"loop_type":"period","bv":false,"nclones":15,"clone_opacity":0.4,"duration":3000,"ease":"linear","dt":0.01,"thumbnail":"http://i.imgur.com/lKvvrN8.png"}

inlet.js

/*modified from Mike Bostock at http://bl.ocks.org/3943967 */

var data = [
{"key":"FL", "pop1":3000, "pop2":4000, "pop3":5000},
{"key":"CA", "pop1":3000, "pop2":3000, "pop3":3000},
{"key":"NY", "pop1":12000, "pop2":5000, "pop3":13000},
{"key":"NC", "pop1":8000, "pop2":21000, "pop3":11000},
{"key":"SC", "pop1":30000, "pop2":12000, "pop3":8000},
{"key":"AZ", "pop1":26614, "pop2":6944, "pop3":30778},
{"key":"TX", "pop1":8000, "pop2":12088, "pop3":20000}
];
 
var n = 3, // number of layers
    m = data.length, // number of samples per layer
    stack = d3.layout.stack(),
    labels = data.map(function(d) {return d.key;}),
    
    //go through each layer (pop1, pop2 etc, that's the range(n) part)
    //then go through each object in data and pull out that objects's population data
    //and put it into an array where x is the index and y is the number
    layers = stack(d3.range(n).map(function(d) { 
                var a = [];
      			for (var i = 0; i < m; ++i) {
        			a[i] = {x: i, y: data[i]['pop' + (d+1)]};  
      			}
  				return a;
             })),
    
	//the largest single layer
    yGroupMax = d3.max(layers, function(layer) { return d3.max(layer, function(d) { return d.y; }); }),
    //the largest stack
    yStackMax = d3.max(layers, function(layer) { return d3.max(layer, function(d) { return d.y0 + d.y; }); });

var margin = {top: 40, right: 10, bottom: 20, left: 50},
    width = 677 - margin.left - margin.right,
    height = 533 - margin.top - margin.bottom;

var y = d3.scale.ordinal()
    .domain(d3.range(m))
    .rangeRoundBands([2, height], .08);

var x = d3.scale.linear()
    .domain([0, yStackMax])
    .range([0, width]);

var color = d3.scale.linear()
    .domain([0, n - 1])
    .range(["#aad", "#556"]);

var svg = d3.select("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 layer = svg.selectAll(".layer")
    .data(layers)
  .enter().append("g")
    .attr("class", "layer")
    .style("fill", function(d, i) { return color(i); });

layer.selectAll("rect")
    .data(function(d) { return d; })
  	.enter().append("rect")
    .attr("y", function(d) { return y(d.x); })
	.attr("x", function(d) { return x(d.y0); })
    .attr("height", y.rangeBand())
    .attr("width", function(d) { return x(d.y); });

var yAxis = d3.svg.axis()
    .scale(y)
    .tickSize(1)
    .tickPadding(6)
	.tickValues(labels)
    .orient("left");

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

This gist was very helpful in helping me understand stacked bar graphs, but the tick labels don't work since .tickValues() only takes numbers. Here's what worked for me:

var yLabels = d3.scale.ordinal()
            .domain(labels)
            .rangeRoundBands([0, height], .1);

        var yAxis = d3.svg.axis()
            .scale(yLabels)
            .ticks(7)
            .tickSize(1)
            .orient("left");

The .tickRoundBands() takes the place of .tickPadding() for more evenly-spaced ticks that are dynamically calculated. Hope this helps!