Evaluations "Histogram" example code

This "histogram" is actually a bar chart in d3 taxonomy.

<!DOCTYPE html>
<meta charset="utf-8">
<style>
.bar {
  fill: steelblue;
}
.bar:hover {
  fill: brown;
}
.axis--x path {
  display: none;
}
</style>
<svg width="960" height="500"></svg>
<script src="https://d3js.org/d3.v4.min.js"></script>
<script>
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;
var x = d3.scaleBand().rangeRound([0, width]).padding(0.1),
    y = d3.scaleLinear().rangeRound([height, 0]);
var g = svg.append("g")
    .attr("transform", "translate(" + margin.left + "," + margin.top + ")");
d3.tsv("data.tsv", function(d) {
  d.count = +d.count;
  return d;
}, function(error, data) {
  if (error) throw error;
  x.domain(data.map(function(d) { return d.response; }));
  y.domain([0, d3.max(data, function(d) { return d.count; })]);
  g.append("g")
      .attr("class", "axis axis--x")
      .attr("transform", "translate(0," + height + ")")
      .call(d3.axisBottom(x));
  g.append("g")
      .attr("class", "axis axis--y")
      .call(d3.axisLeft(y).ticks(10, ",.0f"))
    .append("text")
      .attr("transform", "rotate(-90)")
      .attr("y", 6)
      .attr("dy", "0.71em")
      .attr("text-anchor", "end")
      .text("Count");
  g.selectAll(".bar")
    .data(data)
    .enter().append("rect")
      .attr("class", "bar")
      .attr("x", function(d) { return x(d.response); })
      .attr("y", function(d) { return y(d.count); })
      .attr("width", x.bandwidth())
      .attr("height", function(d) { return height - y(d.count); });
});
</script>

https://d3js.org/d3.v4.min.js