|
<!DOCTYPE html> |
|
<style> |
|
|
|
.axis .domain { |
|
display: none; |
|
} |
|
|
|
</style> |
|
<svg width="960" height="500"></svg> |
|
<script src="https://d3js.org/d3.v4.min.js"></script> |
|
<script> |
|
|
|
|
|
// Commented version of |
|
// https://bl.ocks.org/mbostock/3887051 |
|
|
|
// Variables |
|
var svg = d3.select("svg"), |
|
margin = {top: 20, right: 20, bottom: 30, left: 40}, |
|
width = +svg.attr("width") - margin.left - margin.right, |
|
height = +svg.attr("height") - margin.top - margin.bottom; |
|
|
|
// SVG G to provide D3 Margin Convention |
|
var g = svg.append("g").attr("transform", "translate(" + margin.left + "," + margin.top + ")"); |
|
|
|
// X0 (horizontal axis) represents the state categories |
|
var x0 = d3.scaleBand() |
|
.rangeRound([0, width]) |
|
.paddingInner(0.1); |
|
|
|
// X1 (horizontal axis) represents the age group categories |
|
var x1 = d3.scaleBand() |
|
.padding(0.05); |
|
|
|
// Y (vertical axis) represents the population in millions |
|
var y = d3.scaleLinear() |
|
.rangeRound([height, 0]); |
|
|
|
// Z represents the color scheme to be used for the various age groups |
|
var z = d3.scaleOrdinal() |
|
.range(["#98abc5", "#8a89a6", "#7b6888", "#6b486b", "#a05d56", "#d0743c", "#ff8c00"]); |
|
|
|
// Define variable to give us access to AJAX callback function data |
|
var outsideData; |
|
|
|
// CSV AJAX call to ingest data |
|
// data file requested: data.csv |
|
// function to process data: function(d, i, columns) {...} |
|
// function to be used on call back: function(error, data) {...} |
|
d3.csv("data.csv", function(d, i, columns) { |
|
for (var i = 1, n = columns.length; i < n; ++i) d[columns[i]] = +d[columns[i]]; |
|
return d; |
|
}, function(error, data) { |
|
if (error) throw error; |
|
|
|
// assign internal data variable to outsideData variable so we can see data |
|
// once the AJAX callback function has been run. |
|
outsideData = data; |
|
|
|
// Get the keys by taking a slice off of the column headings |
|
// (means remove the element 0, and return array from index 1 to end) |
|
// Returns array containing: |
|
// "Under 5 Years", "5 to 13 Years", "14 to 17 Years", |
|
// "18 to 24 Years", "25 to 44 Years", "45 to 64 Years", |
|
// "65 Years and Over" |
|
var keys = data.columns.slice(1); |
|
|
|
// Finish defining the X0 (horizontal) state categories scale |
|
x0.domain(data.map(function(d) { return d.State; })); |
|
|
|
// Finish defining the X1 (horizontal) state categories scale |
|
// Use the bandwidth of each state to set to range of x1 |
|
// The rounding gives a nice visual effect |
|
x1.domain(keys).rangeRound([0, x0.bandwidth()]); |
|
|
|
// Finish defining the Y axis |
|
// Note the following: |
|
// - d3.max(data...) |
|
// - d3.max(keys, ...) |
|
// => Think of it as a nested for loop |
|
// => loop through each state and then within each state loop through each age group |
|
y.domain([0, d3.max(data, function(d) { return d3.max(keys, function(key) { return d[key]; }); })]).nice(); |
|
|
|
// Double Data Join |
|
// First data join will give us the states |
|
// - Each g receives state and age group object |
|
// Second data join will give us the rectangles |
|
// - Within the data join, we build a new object from scratch |
|
// - These will be the specific age groups |
|
// - Each rectangle receives the specific age group per state |
|
// - By the end of this, we have a small bar chart for each agre group. |
|
g.append("g") |
|
.selectAll("g") |
|
.data(data) |
|
.enter().append("g") |
|
.attr("transform", function(d) { return "translate(" + x0(d.State) + ",0)"; }) |
|
.selectAll("rect") |
|
.data(function(d) { return keys.map(function(key) { return {key: key, value: d[key]}; }); }) |
|
.enter().append("rect") |
|
.attr("x", function(d) { return x1(d.key); }) |
|
.attr("y", function(d) { return y(d.value); }) |
|
.attr("width", x1.bandwidth()) |
|
.attr("height", function(d) { return height - y(d.value); }) |
|
.attr("fill", function(d) { return z(d.key); }); |
|
|
|
// Create the X Axis |
|
g.append("g") |
|
.attr("class", "axis") |
|
.attr("transform", "translate(0," + height + ")") |
|
.call(d3.axisBottom(x0)); |
|
|
|
// Create the Y Axis |
|
g.append("g") |
|
.attr("class", "axis") |
|
.call(d3.axisLeft(y).ticks(null, "s")) |
|
.append("text") |
|
.attr("x", 2) |
|
.attr("y", y(y.ticks().pop()) + 0.5) |
|
.attr("dy", "0.32em") |
|
.attr("fill", "#000") |
|
.attr("font-weight", "bold") |
|
.attr("text-anchor", "start") |
|
.text("Population"); |
|
|
|
// Create the legend g's |
|
// Note the data join |
|
// Note the transform translate based on the selection element index |
|
var legend = g.append("g") |
|
.attr("font-family", "sans-serif") |
|
.attr("font-size", 10) |
|
.attr("text-anchor", "end") |
|
.selectAll("g") |
|
.data(keys.slice().reverse()) |
|
.enter().append("g") |
|
.attr("transform", function(d, i) { return "translate(0," + i * 20 + ")"; }); |
|
|
|
// Create rectangles for each legend g |
|
// Pass rect index to Z color ordinal scale |
|
legend.append("rect") |
|
.attr("x", width - 19) |
|
.attr("width", 19) |
|
.attr("height", 19) |
|
.attr("fill", z); |
|
|
|
// Create text for each legend g |
|
// Use the data that it inherts to create the SVG text |
|
legend.append("text") |
|
.attr("x", width - 24) |
|
.attr("y", 9.5) |
|
.attr("dy", "0.32em") |
|
.text(function(d) { return d; }); |
|
}); |
|
|
|
</script> |