Chart.js multiple series with same scale

Question

I have a stacked bar chart with an unstacked line chart combo chart using Chart.js. I need the stacked bars and unstacked lines to appear on the same axis. It doesn't appear that I can do this, so I put them on different axes so that one could be stacked and the other not (e.g., overlay a capacity line over production of different parts). However, if they must be on different axes, then I need them to have the same scale. I could not find a way to force the axes to have the same scale automatically, so I am forced to try to compute my own scale and set them each to that. This isn't ideal and I would prefer if I could just use a setting to force them to use the same scale. Is this possible?

Here is a post that is basically the same question as I am: Chart.js place both series on same scale The only difference is that I need to stack my bar series which prevents me from using the same axes.

Answer 1

I might be misunderstanding what you are trying to do, but it is possible to create a stacked bar chart with an un-stacked line chart combo on the same axis.

Here is an example configuration showing how do to it.

var myChart = new Chart(ctx, {
  type: 'bar',
  data: {
    labels: ["January", "February", "March", "April", "May", "June", "July"],
    datasets: [{
      type: 'line',
      label: 'Dataset 1',
      borderColor: window.chartColors.blue,
      borderWidth: 2,
      fill: false,
      data: [5, 3, 4, 10, 8, 9, 2]
    }, {
      type: 'bar',
      label: 'Dataset 2',
      backgroundColor: window.chartColors.red,
      stack: 'Stack 0',
      data: [2, 4, 1, 3, 7, 3, 6],
      borderColor: 'white',
      borderWidth: 2
    }, {
      type: 'bar',
      label: 'Dataset 3',
      backgroundColor: window.chartColors.green,
      stack: 'Stack 0',
      data: [7, 2, 4, 5, 6, 4, 2]
    }]
  },
  options: {
    responsive: true,
    title: {
      display: true,
      text: 'Chart.js Stacked Bar and Unstacked Line Combo Chart'
    },
    tooltips: {
      mode: 'index',
      intersect: true
    },
    scales: {
      xAxes: [{
        stacked: true,
      }]
    }
  }
});

Here is a working codepen example as well.