Bar chart from external JSON file

A simple bar chart build using data from an external JSON file.

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

.bar{
    fill: steelblue;
  }

.bar:hover{
    fill: brown;
  }

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

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

</style>
</head>

// set the ranges
var x = d3.scale.ordinal().rangeRoundBands([0, width], .05);

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

// define the axis
var xAxis = d3.svg.axis()
    .scale(x)
    .orient("bottom")

var yAxis = d3.svg.axis()
    .scale(y)
    .orient("left")
    .ticks(10);

// add the SVG element
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 + ")");

// load the data
d3.json("data.json", function(error, data) {

data.forEach(function(d) {
        d.Letter = d.Letter;
        d.Freq = +d.Freq;
    });
	
  // scale the range of the data
  x.domain(data.map(function(d) { return d.Letter; }));
  y.domain([0, d3.max(data, function(d) { return d.Freq; })]);

// add axis
  svg.append("g")
      .attr("class", "x axis")
      .attr("transform", "translate(0," + height + ")")
      .call(xAxis)
    .selectAll("text")
      .style("text-anchor", "end")
      .attr("dx", "-.8em")
      .attr("dy", "-.55em")
      .attr("transform", "rotate(-90)" );

svg.append("g")
      .attr("class", "y axis")
      .call(yAxis)
    .append("text")
      .attr("transform", "rotate(-90)")
      .attr("y", 5)
      .attr("dy", ".71em")
      .style("text-anchor", "end")
      .text("Frequency");

// Add bar chart
  svg.selectAll("bar")
      .data(data)
    .enter().append("rect")
      .attr("class", "bar")
      .attr("x", function(d) { return x(d.Letter); })
      .attr("width", x.rangeBand())
      .attr("y", function(d) { return y(d.Freq); })
      .attr("height", function(d) { return height - y(d.Freq); });

});

</script>

</body>

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

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