D3 Examples - 2017 MTA Average Ridership

2017 MTA Average Ridership
This is a scatter plot of average MTA ridership for months in 2017. The x-axis is month, the y-axis is the average ridership, and the color of the point is the type of mta mode of transportation that was taken.
The data shown here comes from Data.gov: MTA Average Weekday Ridership by Month. The data shown in the plot is only 2017.
xxxxxxxxxx
 
<!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>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/d3-legend/2.24.0/d3-legend.min.js"></script>
    <title>2017 Average Commuter Ridership in Maryland</title>
    <style>
      body {
        margin: 0px;
      }
      .domain {
        display: none;
      }
      .tick line {
        stroke: #C0C0BB;
      }
      .tick text, .legendCells text {
        fill: #8E8883;
        font-size: 12pt;
        font-family: sans-serif;
      }
      .axis-label, .legend-label {
        fill: #635F5D;
        font-size: 15pt;
        font-family: sans-serif;
      }
      #chart {
        position: fixed;
        left:0px;
        right:0px;
        top:0px;
        bottom:0px;
      }
    </style>
  </head>
  <body>
    <svg width="960" height="500"></svg>
    <div id = "chart"></div>
    <script>
​
      const xValue = d => d.Month;
      const xLabel = 'Month';
      const yValue = d => d.Avg_Riders;
      const yLabel = 'Average Ridership';
      const colorValue = d => d.Type;
      const colorLabel = 'Type';
      const margin = { left: 100, right: 250, top: 20, bottom: 120 };
      
      const row = d => {
        d.Month = d['Month']
        d.Avg_Riders = +d.Avg_Riders
        return d;
      };
      
      var chartDiv = document.getElementById("chart")
      var svg = d3.select(chartDiv).append("svg");
      
      const xScale = d3.scalePoint();
      const yScale = d3.scaleLinear();
      const colorScale = d3.scaleOrdinal()
        .range(d3.schemeCategory10);
      
      const colorLegend = d3.legendColor()
        .scale(colorScale)
        .shape('circle');
      
      const g = svg.append('g');
      const datag = g.append('g');
      
      const xAxisG = g.append('g');
      const xText = xAxisG.append('text')
        .attr('class','axis-label')
      const yAxisG = g.append('g');
      const yText = yAxisG.append('text')
        .attr('class','axis-label')
      const colorLegendG = g.append('g')
      
      
      function redraw() {
        
        var width = chartDiv.clientWidth;
        var height = chartDiv.clientHeight;
        const innerWidth = width - margin.left - margin.right;
        const innerHeight = height - margin.top - margin.bottom;
        
        svg
            .attr("width",width)
            .attr("height",height);
        
       
      g.attr('transform', `translate(${margin.left},${margin.top})`);
      xAxisG
        .attr('transform', `translate(0, ${innerHeight})`);
      xText
        .attr('x', innerWidth/2)
        .attr('y',70)
        .text(xLabel);
      
      yText
        .attr('x',-innerHeight/2)
        .attr('y',-75)
        .attr('transform',`rotate(-90)`)
        .style('text-anchor','middle')
        .text(yLabel)
        
        
      colorLegendG.attr('transform', `translate(${innerWidth + 60}, 150)`);
​
      const xAxis = d3.axisBottom()
        .scale(xScale)
        .tickPadding(15)
        .tickSize(-innerHeight);
​
      const yTicks = 5;
      const yAxis = d3.axisLeft()
        .scale(yScale)
        .ticks(yTicks)
        .tickPadding(15)
        .tickSize(-innerWidth);
​
​
      d3.csv('commuter_data.csv', row, data => {
        xScale
          .domain(data.map(xValue))
          .range([0, innerWidth]);
​
        yScale
          .domain(d3.extent(data, yValue))
          .range([innerHeight, 0])
          .nice(yTicks);
        
        var circles = datag.selectAll('circle').data(data)
        
        circles
            .enter()
            .append('circle')
                .attr('fill-opacity', 0.6)
        .merge(circles)
            .attr('cx', d => xScale(xValue(d)))
          .attr('cy', d => yScale(yValue(d)))
          .attr('fill', d => colorScale(colorValue(d)))
            .attr('r', 8);
​
        xAxisG.call(xAxis);
        yAxisG.call(yAxis);
        colorLegendG.call(colorLegend)
          .selectAll('.cell text')
            .attr('dy', '0.1em');
      });
      }
      
      redraw();
      window.addEventListener("resize",redraw);
      
​
    </script>
  </body>
</html>
​
​
    