linkHorizontal

<!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; }
  </style>
</head>

<body>
  <svg width="1200" height="700"></svg>
  <script>
    var data = [{
  source: {
    y: 150,
    x: 95
  },
  target: {
    y: 200,
    x: 0
  }
}, {
  source: {
    y: 150,
    x: 75
  },
  target: {
    y: 0,
    x: 0
  }
}, {
  source: {
    y: 250,
    x: 75
  },
  target: {
    y: 150,
    x: 150
  }
}, ];

var svg = d3.select("svg");

svg.selectAll(null)
  .data(data)
  .enter()
  .append("path")
  .attr("fill", "none")
  .attr("stroke", "blue")
  .attr("d", linkVertical);

</script>
</body>

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