d3 update with custom axis and labels

d3 update with custom axis and labels

CSS

.bar {
  fill: steelblue;
}

.bar:hover {
  fill: brown;
}

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

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

.x.axis path {
  display: none;
}

JavaScript

var margin = {
    top: 20,
    right: 20,
    bottom: 30,
    left: 40
  },
  width = 560 - 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")
  .ticks(10, "%");

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 + ")");

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

svg.append("g")
  .attr("class", "y axis")
  .append("text") 
  .attr("transform", "rotate(-90)")
  .attr("y", 6)
  .attr("dy", ".71em")
  .style("text-anchor", "end")
  .text("Frequency");

function draw(data) {
  x.domain(data.map(function(d) {
    return d.letter;
  }));
  y.domain([0, d3.max(data, function(d) {
    return d.frequency;
  })]);
  
  
  var labels = svg
	.selectAll(".topLabel")
  .data(data, function(d) {
      return d.letter;
    });
    
labels
.exit()
.remove();

labels
  .enter()
  .append("text")
  .attr("class", "topLabel")
  .attr("text-anchor", "middle")
  .attr("fill", "black")
  
  labels
  .attr("x", function(d, i) {
    return x(d.letter) + 7.5;
  })
  .attr("y", function(d, i) {
    return y(d.frequency);
  })
  .text(function(d, i) {
    return d.letter;
  });

    
var labels = svg
	.selectAll(".bartext")
  .data(data, function(d) {
      return d.letter;
    });
    
labels
.exit()
.remove();

labels
  .enter()
  .append("text")
  .attr("class", "bartext")
  .attr("text-anchor", "middle")
  .attr("fill", "black");
  
  labels
  .attr("x", function(d, i) {
    return x(d.letter) + 7.5;
  })
  .attr("y", function(d, i) {
    return height + 15;
  })
  .text(function(d, i) {
    return...