1-2_r

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width">
  <title>JS Bin</title>
</head>
<body>
  <svg height="1000" width="1000">
    <rect x="0" y="0" width="100" height="50"></rect>
    <rect x="0" y="100" width="200" height="50"></rect>
    <rect x="0" y="200" width="300" height="50"></rect>
  </svg>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/d3/4.2.3/d3.min.js"></script>
  <script>

    let my_data = [1, 2, 3, 4, 5];
    let svg = d3.select('svg');

    svg.selectAll('rect')
      .data(my_data)
      .enter()
      .append('rect')
      .attr('width', function(d, i, nodes) {
        return d * 100;
      })
      .attr('height', 50)
      .attr('x', 0)
      .attr('y', function(d, i, nodes) {
        return (d - 1) * 100;
      });

  </script>
</body>
</html>