Scatter Plot Axis Labels

Part of the video course: D3.js in Motion.

An example of axis labels using D3.

This shows the "Iris" dataset. Originally published at UCI Machine Learning Repository: Iris Data Set, this small dataset from 1936 is often used for testing out machine learning algorithms and visualizations. Each row of the table represents an iris flower, including its species and dimensions of its botanical parts, sepal and petal, in centimeters.

<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width">
    <script src="https://d3js.org/d3.v4.min.js"></script>
    <title>Basic Scatter Plot</title>
    <style>
      body {
        margin: 0px;
      }
      .tick {
        font-size: 28pt;
      }
      .axis-label {
        fill: black;
        font-size: 50pt;
        font-family: sans-serif;
      }
    </style>
  </head>
  <body>
    <svg width="960" height="500"></svg>
    <script>
      const xValue = d => d.sepalLength;
      const xLabel = 'Sepal Length';
      const yValue = d => d.petalLength;
      const yLabel = 'Petal Length';
      const margin = { left: 120, right: 30, top: 20, bottom: 120 };

const svg = d3.select('svg');
      const width = svg.attr('width');
      const height = svg.attr('height');
      const innerWidth = width - margin.left - margin.right;
      const innerHeight = height - margin.top - margin.bottom;

xAxisG.append('text')
          .attr('class', 'axis-label')
          .attr('x', innerWidth / 2)
          .attr('y', 100)
          .text(xLabel);

yAxisG.append('text')
          .attr('class', 'axis-label')
          .attr('x', -innerHeight / 2)
          .attr('y', -60)
          .attr('transform', `rotate(-90)`)
          .style('text-anchor', 'middle')
          .text(yLabel);

const xScale = d3.scaleLinear();
      const yScale = d3.scaleLinear();

const xAxis = d3.axisBottom()
        .scale(xScale)
        .tickPadding(15)
        .tickSize(-innerHeight);

const yAxis = d3.axisLeft()
        .scale(yScale)
        .ticks(5)
        .tickPadding(15)
        .tickSize(-innerWidth);

const row = d => {
        d.petalLength = +d.petalLength;
        d.petalWidth = +d.petalWidth;
        d.sepalLength = +d.sepalLength;
        d.sepalWidth = +d.sepalWidth;
        return d;
      };

d3.csv('iris.csv', row, data => {
        xScale
          .domain(d3.extent(data, xValue))
          .range([0, innerWidth])
          .nice();

yScale
          .domain(d3.extent(data, yValue))
          .range([innerHeight, 0])
          .nice();

g.selectAll('circle').data(data)
          .enter().append('circle')
            .attr('cx', d => xScale(xValue(d)))
            .attr('cy', d => yScale(yValue(d)))
            .attr('r', 8);

xAxisG.call(xAxis);
        yAxisG.call(yAxis);
      });
    </script>
  </body>
</html>

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