D3v4

d3 version 4

by Justin Maat

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/4.9.1/d3.min.js"></script>
<div id="hello">
<svg width="960" height="500"></svg>
</div>

CSS

.bar {
  fill: steelblue;
}
.bar:hover {
  fill: brown;
}
.axis--x path {
  display: none;
}
.line {
  fill: none;
  stroke: steelblue;
  stroke-width: 3px;
}
.circle {
  fill: steelblue;
}

JavaScript

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 d2 = [
  {a: 'A', value: '10'},
  {a: 'B', value: '20'},
  {a: 'C', value: '30'},
  {a: 'D', value: '40'},
	{a: 'E', value: '50'}
  ];

console.log('width ', width);

var xScale = d3
  .scaleBand()
  .range([0, width])
  .domain(d2.map(function(d) { return d.a; }))
  ;
				var areaFn = d3.area()
					.x(function(d) {
							console.log('xScale(d.x): ', xScale(d.a));
							return xScale(d.a);
					});
          areaFn(d2);
//					.y0(h)
//					.y1(d => yScale(d.y));

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 + ")");

    const data = [
      { letter: 'A', frequency: .08167 },
      { letter: 'B', frequency: .01492 },
      { letter: 'C', frequency: .02782 },
      { letter: 'D', frequency: .04253 },
      { letter: 'E', frequency: .12702 },
    ];
    
  var line = d3.line()
    .x(function(d) { return x(d.letter); })
    .y(function(d) { return y(d.frequency); })
  x.domain(data.map(function(d) { return d.letter; }));
  y.domain([0, d3.max(data, function(d) { return d.frequency; })]);
  g.append("g")
      .attr("class", "axis axis--x")
      .attr("transform", "translate(0," + height + ")")
      .call(d3.axisBottom(x));
  g.append("path")
    .datum(data)
    .attr("class", "line")
    .attr("d", line);
  g.selectAll("circle")
    .data(data)
  .enter().append("circle")
    .attr("class", "circle")
    .attr("cx", function(d) { return x(d.letter); })
    .attr("cy", function(d) { return y(d.frequency); })
    .attr("r", 4);