var data = d3.select('#cars').html().trim();

  data = d3.csv.parse(data, function (d) {

    return {

      model: d.Model,

      origin: d.Origin,

      year: +d.Year,

      cylinders: +d.Cylinders,

      horsepower: +d.Horsepower,

      mpg: +d.MPG,

      weight: +d.Weight

    };

  });

​

// Create the SVG element

var width = 500;

var height = 400;

​

var svg = d3.select('body')

  .append('svg')

  .attr('width', width)

  .attr('height', height);

​

// Calculate the max weight and car model names

var max_weight = d3.max(data, function(d) {

  return d.weight;

});

​

var model_names = data.map(function(d){

  return d.model;

});

​

// Define the margins

var margins = {

  top: 20,

  right: 20,

  bottom: 50,

  left: 110

};

var graphWidth = width - margins.right - margins.left;

var graphHeight = height - margins.top - margins.bottom;

​

// Make a group for drawing the chart

var chart = svg.append('g')

  .attr('transform', 'translate(' + margins.left + ',' + margins.top + ')');

​

// Create the scales

var x = d3.scale.linear()

  .range([0, graphWidth])

  .domain([0, max_weight]);

​

var y = d3.scale.ordinal()

  .domain(model_names)

  .rangeRoundBands([ 0, graphHeight], 0.1);

​

// Draw the axes

var xAxis = d3.svg.axis()

  .scale(x)

  .orient("top");

​

chart.append("g")

  .classed("x axis", true)

  .call(xAxis);

​

var yAxis = d3.svg.axis()

  .scale(y)

  .orient("left");

​

chart.append("g")

  .classed("y axis", true)

  .call(yAxis);

​

// Draw the bars

var bars = chart.selectAll('rect.bar')

                .data(data);

​

bars.enter()

    .append('rect')

    .attr('class', 'bar');

​

bars.exit()

    .remove();

​

bars.attr('x', 0)

    .attr('y', function(d) {

      return y(d.model);

    })

    .attr('height', y.rangeBand())

    .attr('width', function(d) {

      return x(d.weight);

    });

​

var cylinders = data.map(function(d) {

  return d.cylinders;

});

​

var color = d3.scale.category10()

  .domain(cylinders);

​

bars.attr('fill', function(d) {

      return color(d.cylinders);

    });