javascript - Grouped bar charts, in chart.js

Question

I've seen other javascript charting libraries that supported grouped barcharts, of the sort in the image below. I've not seen this as an explicit option in chart.js's online editor.

Is it possible to do grouped bar charts of this sort in chart.js? Is it easy? Is there a template for it in their online editor?

Answer 1

Yes, you can provide multiple data sets using the datasets property, which is an array of containing groupings of values. Each data set contains a series of values in data that correspond to the labels.

See two slightly different examples below depending on your version of Chart.js.

---

Chart.js v1.x

var ctx = document.getElementById("myChart").getContext("2d");

var data = {
    labels: ["Chocolate", "Vanilla", "Strawberry"],
    datasets: [
        {
            label: "Blue",
            fillColor: "blue",
            data: [3,7,4]
        },
        {
            label: "Red",
            fillColor: "red",
            data: [4,3,5]
        },
        {
            label: "Green",
            fillColor: "green",
            data: [7,2,6]
        }
    ]
};

var myBarChart = new Chart(ctx).Bar(data, { barValueSpacing: 20 });

See this JSFiddle.

---

Chart.js v2.x

var ctx = document.getElementById("myChart").getContext("2d");

var data = {
    labels: ["Chocolate", "Vanilla", "Strawberry"],
    datasets: [
        {
            label: "Blue",
            backgroundColor: "blue",
            data: [3,7,4]
        },
        {
            label: "Red",
            backgroundColor: "red",
            data: [4,3,5]
        },
        {
            label: "Green",
            backgroundColor: "green",
            data: [7,2,6]
        }
    ]
};

var myBarChart = new Chart(ctx, {
    type: 'bar',
    data: data,
    options: {
        barValueSpacing: 20,
        scales: {
            yAxes: [{
                ticks: {
                    min: 0,
                }
            }]
        }
    }
});

See this JSFiddle.