atestu/README.mdown

## README.md

      
    Raw
  

              README.md
            
          
    A simple SVG bar chart. Part of the tutorial series Let’s Make a Bar Chart.

  
## data.tsv

          
            name
            value

            
              A
              .08167

            
              B
              .01492

            
              C
              .02782

            
              D
              .04253

            
              E
              .12702

            
              F
              .02288

            
              G
              .02015

            
              H
              .06094

            
              I
              .06966

            
              J
              .00153

            
              K
              .00772

            
              L
              .04025

            
              M
              .02406

            
              N
              .06749

            
              O
              .07507

            
              P
              .01929

            
              Q
              .00095

            
              R
              .05987

            
              S
              .06327

            
              T
              .09056

            
              U
              .02758

            
              V
              .00978

            
              W
              .02360

            
              X
              .00150

            
              Y
              .01974

            
              Z
              .00074

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

.bar {
  fill: steelblue;
}

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

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

.x.axis path {
  display: none;
}

</style>
<svg class="chart"></svg>
<script src="http://d3js.org/d3.v3.min.js"></script>
<script>

// all of these variables are independent of the data, so we exclude them from the draw function
var margin = {top: 20, right: 30, 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()
    .range([height, 0]);

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

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

var chart = d3.select(".chart")
    .attr("width", width + margin.left + margin.right)
    .attr("height", height + margin.top + margin.bottom)
  .append("g")
    .attr("transform", "translate(" + margin.left + "," + margin.top + ")");

var gXAxis = chart.append("g")
    .attr("class", "x axis")
    .attr("transform", "translate(0," + height + ")");

var gYAxis = chart.append("g")
    .attr("class", "y axis");

// this is the function that will be called each time we draw the chart
function draw () {
  d3.tsv("data.tsv", type, function(error, data) {
    // the data may have changed so we need to update the domain of our scales
    x.domain(data.map(function(d) { return d.name; }));
    y.domain([0, d3.max(data, function(d) { return d.value; })]);

    // we update the axis to reflect the new scale domains
    gXAxis.call(xAxis);
    gYAxis.call(yAxis);

    var bars = chart.selectAll(".bar").data(data);

    // if there are new bars since we last called draw (or if it's the first time), we add them now
    bars
      .enter().append("rect")
        .attr("class", "bar");

    // we update the bars with new attributes based on the new data
    bars
        .attr("x", function(d) { return x(d.name); })
        .attr("y", function(d) { return y(d.value); })
        .attr("height", function(d) { return height - y(d.value); })
        .attr("width", x.rangeBand());

    // maybe some bars are not present in the new data, let's remove them!
    bars.exit().remove();
  });
}

function type(d) {
  d.value = +d.value; // coerce to number
  return d;
}

draw();
// we can call draw any number of time, axis won't be re drawn, just updated
draw();
// bars won't superpose, they'll just be updated or removed
draw();
// such is the magic of d3 data joins! http://bost.ocks.org/mike/join/
draw();

</script>

## thumbnail.png

      
    Raw
  

              thumbnail.png
	name	value
	A	.08167
	B	.01492
	C	.02782
	D	.04253
	E	.12702
	F	.02288
	G	.02015
	H	.06094
	I	.06966
	J	.00153
	K	.00772
	L	.04025
	M	.02406
	N	.06749
	O	.07507
	P	.01929
	Q	.00095
	R	.05987
	S	.06327
	T	.09056
	U	.02758
	V	.00978
	W	.02360
	X	.00150
	Y	.01974
	Z	.00074
	<!DOCTYPE html>
	<meta charset="utf-8">
	<style>

	.bar {
	fill: steelblue;
	}

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

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

	.x.axis path {
	display: none;
	}

	</style>
	<svg class="chart"></svg>
	<script src="http://d3js.org/d3.v3.min.js"></script>
	<script>

	// all of these variables are independent of the data, so we exclude them from the draw function
	var margin = {top: 20, right: 30, 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()
	.range([height, 0]);

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

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

	var chart = d3.select(".chart")
	.attr("width", width + margin.left + margin.right)
	.attr("height", height + margin.top + margin.bottom)
	.append("g")
	.attr("transform", "translate(" + margin.left + "," + margin.top + ")");

	var gXAxis = chart.append("g")
	.attr("class", "x axis")
	.attr("transform", "translate(0," + height + ")");

	var gYAxis = chart.append("g")
	.attr("class", "y axis");

	// this is the function that will be called each time we draw the chart
	function draw () {
	d3.tsv("data.tsv", type, function(error, data) {
	// the data may have changed so we need to update the domain of our scales
	x.domain(data.map(function(d) { return d.name; }));
	y.domain([0, d3.max(data, function(d) { return d.value; })]);

	// we update the axis to reflect the new scale domains
	gXAxis.call(xAxis);
	gYAxis.call(yAxis);

	var bars = chart.selectAll(".bar").data(data);

	// if there are new bars since we last called draw (or if it's the first time), we add them now
	bars
	.enter().append("rect")
	.attr("class", "bar");

	// we update the bars with new attributes based on the new data
	bars
	.attr("x", function(d) { return x(d.name); })
	.attr("y", function(d) { return y(d.value); })
	.attr("height", function(d) { return height - y(d.value); })
	.attr("width", x.rangeBand());

	// maybe some bars are not present in the new data, let's remove them!
	bars.exit().remove();
	});
	}

	function type(d) {
	d.value = +d.value; // coerce to number
	return d;
	}

	draw();
	// we can call draw any number of time, axis won't be re drawn, just updated
	draw();
	// bars won't superpose, they'll just be updated or removed
	draw();
	// such is the magic of d3 data joins! http://bost.ocks.org/mike/join/
	draw();

	</script>