ttps://raw.githubusercontent.com/holtzy/D3-graph-gallery/master/DATA/data_stacked.csv", function(data) {

  // List of groups = what we want on the X axis
  var keys = d3.map(data, function(d){return(d.group)}).keys()
  var subgroups = d3.map(data, function(d){return(d.subgroup)}).keys()

  // Add X axis
  var x = d3.scaleBand()
      .domain(keys)       // This is what is written on the Axis: from 0 to 100
      .range([0, width])                       // This is where the axis is placed: from 100 px to 80