("fill", "none")

    // A function that update the chart
    function update(selectedGroup) {

      // Create new data with the selection?
      const dataFilter = data.map(function(d){return {time: d.time, value:d[selectedGroup]} })

      // Give these new data to update line
      line
          .datum(dataFilter)
          .transition()
          .duration(1000)
          .attr("d", d3.line()
            .x(function(d) { return x(+d.time) })
            .y(function(d) { return y(+d.value) })
         