Ch. 4, Fig. 20 - D3.js in Action

This is the code for Chapter 4, Figure 20 from D3.js in Action demonstrating several d3.svg.line() interpolation options.

<html>
<head>
  <title>D3 in Action Chapter 4 - Example 11</title>
  <meta charset="utf-8" />
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.5/d3.min.js"></script>
</head>
<style>
  svg {
    height: 500px;
    width: 500px;
    border: 1px solid gray;
  }
line {
  shape-rendering: crispEdges;
  stroke: #000000;
  }

line.minor  {
  stroke: #777777;
  stroke-dasharray: 2,2;
}

path.domain {
  fill: none;
  stroke: black;
}

</style>
<body>

<div id="viz">
  <svg>
  </svg>
</div>
</body>
  <footer>
    
<script>
d3.csv("tweetdata.csv", lineChart)

function lineChart(data) {

xScale = d3.scale.linear().domain([1,10.5]).range([20,480]);
yScale = d3.scale.linear().domain([0,35]).range([480,20]);

xAxis = d3.svg.axis()
.scale(xScale)
.orient("bottom")
.tickSize(480)
.tickValues([1,2,3,4,5,6,7,8,9,10]);

d3.select("svg").append("g").attr("id", "xAxisG").call(xAxis);
    
yAxis = d3.svg.axis()
.scale(yScale)
.orient("right")
.ticks(10)
.tickSize(480)
.tickSubdivide(true);
    
d3.select("svg").append("g").attr("id", "yAxisG").call(yAxis);

d3.select("svg").selectAll("circle.tweets")
.data(data)
.enter()
.append("circle")
.attr("class", "tweets")
.attr("r", 5)
.attr("cx", function(d) {return xScale(d.day)})
.attr("cy", function(d) {return yScale(d.tweets)})
.style("fill", "black")

d3.select("svg").selectAll("circle.retweets")
.data(data)
.enter()
.append("circle")
.attr("class", "retweets")
.attr("r", 5)
.attr("cx", function(d) {return xScale(d.day)})
.attr("cy", function(d) {return yScale(d.retweets)})
.style("fill", "lightgray")

d3.select("svg").selectAll("circle.favorites")
.data(data)
.enter()
.append("circle")
.attr("class", "favorites")
.attr("r", 5)
.attr("cx", function(d) {return xScale(d.day)})
.attr("cy", function(d) {return yScale(d.favorites)})
.style("fill", "gray");

tweetLine = d3.svg.line()
        .interpolate("cardinal")
        .x(function(d) {
        return xScale(d.day)
    })
        .y(function(d) {
        return yScale(d.tweets)
    })

retweetLine = d3.svg.line()
        .interpolate("basis")
        .x(function(d) {
        return xScale(d.day)
    })
        .y(function(d) {
        return yScale(d.retweets)
    })

favLine = d3.svg.line()
        .interpolate("step-before")
        .x(function(d) {
        return xScale(d.day)
    })
        .y(function(d) {
        return yScale(d.favorites)
    })

d3.select("svg")
        .append("path")
        .attr("d", tweetLine(data))
        .attr("fill", "none")
        .attr("stroke", "darkred")
        .attr("stroke-width", 2)
    
        d3.select("svg")
        .append("path")
        .attr("d", retweetLine(data))
        .attr("fill", "none")
        .attr("stroke", "gray")
        .attr("stroke-width", 3)
    
        d3.select("svg")
        .append("path")
        .attr("d", favLine(data))
        .attr("fill", "none")
        .attr("stroke", "black")
        .attr("stroke-width", 2)

}

</script>
  </footer>

</html>

https://cdnjs.cloudflare.com/ajax/libs/d3/3.5.5/d3.min.js