[basic chart] line chart (d3 v4)

<!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; }
    
    .line {
      fill: none;
      stroke: steelblue;
      stroke-width: 1.5px;
}
  </style>
</head>

<body>
  <script>
    // Feel free to change or delete any of the code you see in this editor!
    var svg = d3.select("body").append("svg")
      .attr("width", 960)
      .attr("height", 300)

var categories = ['a', 'b', 'c', 'd'];
    //var color = d3.scale.category10();  // escala com 10 cores (category10)
    var color = d3.scaleOrdinal(d3.schemeCategory10);
    
    var g = svg.append("g")
        .attr("transform",
          "translate(" + margin.left + "," + margin.top + ")");
    
    for (i in categories) {
      var lineFunction = multiline(categories[i]);
      g.append("path")
        .datum(data) 
        .attr("class", "line")
        .style("stroke", color(i))
        .attr("d", lineFunction);
    }
    
      // Add the X Axis
  		g.append("g")
      .attr("transform", "translate(0," + height + ")")
      .call(d3.axisBottom(x));
    
      // Add the Y Axis
  		g.append("g")
      .call(d3.axisLeft(y));

</script>
</body>

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