Peaks

<!DOCTYPE html>
<head>
  <meta charset="utf-8">
  <script src="https://d3js.org/d3.v4.min.js"></script>
  <style>
    
    
    path {
      stroke: black;
      stroke-width: 2;
      fill: none;
      stroke-linecap: round
    }
    
  </style>
</head>

<body>
  <script>
    
    let w = 500
    let h = 250
    let m = 50
    
    var svg = d3.select("body")
    	.append("svg")
      .attr("width", w + m + m)
      .attr("height", h + m + m)
    
    var g = svg.append("g")
    	.attr("transform", "translate("+ m + "," + m +")")

var data = d3.range(13).map(function(){return Math.random()*10})
    
    var x = d3.scaleLinear()
    	.domain([0, 12])
    	.range([0, w]);

var path = g.append("path")
      .attr("d", line(lineData))

</script>
</body>

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