Legislator Ages

Data from the Sunlight Labs Congress API - get an API key and play around with it!

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

rect.bar {
  fill: steelblue;
}

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

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

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

var format = d3.time.format("%Y-%m-%d");
var yformat = d3.time.format("%Y");

d3.json('legislators.json')
    .get()
    .on('load', function(data) {
        var births = data.response.legislators.map(function(d) {
            return format.parse(d.legislator.birthdate);
        });

var data = d3.nest()
            .key(function(d) {
                return d.getFullYear();
            })
            .entries(births);

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.time.scale()
            .range([0, width]);

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

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

var yAxis = d3.svg.axis()
            .scale(y)
            .orient("left");

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 + ")");

x.domain(d3.extent(data, function(d) { return format.parse(d.key + '-01-01'); }));
        y.domain(d3.extent(data, function(d) { return d.values.length }));

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

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("Frequency");

svg.selectAll(".bar")
            .data(data)
          .enter().append("rect")
            .attr("class", "bar")
            .attr("x", function(d) { return x(format.parse(d.key + '-01-01')); })
            .attr("width", 10)
            .attr("y", function(d) { return y(d.values.length); })
            .attr("height", function(d) { return height - y(d.values.length); });
    });
</script>

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

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