Scales & Axis

<!DOCTYPE html>
<head>
  <meta charset="utf-8">
  <script src="https://d3js.org/d3.v4.min.js"></script>
  <style>
    body { 		margin:0;position:fixed;top:0;right:0;bottom:0;left:0; }
    svg {
      width: 100%;
      height: 100%;
    }
  </style>
</head>

<body>
  <svg>
  </svg>
  <script>
    var city = 'San Francisco';
    var height = 300;
 
    d3.tsv("data.tsv", function(data) {
      var min = d3.min(data, d => d[city]);
      var max = d3.max(data, d => d[city]);
			console.log(min, max)
      // or use extent, which gives back [min, max]
      var extent = d3.extent(data, d => d[city]);
			console.log(extent)
      var yScale = d3.scaleLinear()
        .domain(extent)
        .range([height, 0]);
	
      console.log(yScale);
      var yAxis = d3.axisLeft()
      .scale(yScale); // pass in a scale

d3.select('svg')
      // create a group element we can translate
      // so that the axis will be visible in SVG
      .append('g')
      .attr('transform', 'translate(40, 20)')
      // selection.call(yAxis) is the same as yAxis(selection)
      // and an axis will be created within the selection
      .call(yAxis)
    })
  </script>
</body>

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