{ return d; }) // text showed in the menu
      .attr("value", function (d) { return d; }) // corresponding value returned by the button

    // A color scale: one color for each group
    const myColor = d3.scaleOrdinal()
      .domain(allGroup)
      .range(d3.schemeSet2);

    // Add X axis --> it is a date format
    const x = d3.scaleLinear()
      .domain([0,10])
      .range([ 0, width ]);
    svg.append("g")
      .attr("transform", `translate(0, ${height})`)
      .call(d3.axisBottom(x));

    // A