New dumbbell variation for the Horizontal Bar chart

About

RGraph is a JavaScript charts library based on HTML5 SVG and canvas. RGraph is mature (over 18 years old) and has a wealth of features making it an ideal choice to use for showing charts on your website.

Version 7.10 released

Version 7.10 (released in January 2026) is the latest version of RGraph and contains various updates to the code which you can see on the changelog page. There's also a big tidy up in terms of comments and a significant change to the way that the internal code is referenced which should lead to a performance improvement in effects and animations.

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New HTML datagrid

In the April 2025 (v6.21) release a new datagrid object was added. This makes it easy to add static or dynamic data tables to your pages. It can be used whether you use the canvas or SVG libraries or entirely standalone.

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Get the latest version of RGraph (version 7.10, 18th January 2026) from the download page. You can read the changelog here. There's also older versions available, minified files and links to cdnjs.com hosted libraries.

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License

RGraph can be used for free under the GPL or if that doesn't suit your situation there's an inexpensive (£129) commercial license available.

A new dumbbell chart variation has been added to the Horizontal Bar chart as you can see from the image that's shown here. This particular example is a grouped example, which can be achieved by using multiple HBar chart objects (though the code is quite simple - as you can see below the image).

Dumbbell chart example

The data for the dumbbell chart is slightly different to a Bar chart in that there are two or more scale values given and these values are the points that you will see marked on the chart. It's unlike a stacked Bar chart where the values are accumulative. For example, with a stacked Bar chart, if you give [3,6,8] you will see bars that go from 0-3, 3-9 and 9-17). Whereas with a dumbbell chart you will see a dumbell that starts at 3, has a section that goes up to 6 and then finishes at 8.

Here's the code that makes the dumbbell chart example above:

<script>
    new RGraph.HBar({
        id: 'cvs',
        data: [0,0,0,0],
        options: {
            yaxisLabels: ['Monday','Tuesday','Wednesday','Thursday'],
            yaxisLinewidth: 3,
            yaxisTickmarks: false,
            xaxis: false,
            marginLeftAuto: false,
            marginLeft: 200,
            textSize: 23,
            yaxisLabelsOffsetx: -10,
            xaxisScaleMax: 20
        }
    }).draw();



    new RGraph.HBar({
        id: 'cvs',
        data: [[3,20],[5,10],[10,15],[15,20]],
        options: {
            variant: 'dumbbell',
            // variantDumbbellLinewidth: 4,
            // variantDumbbellEndLeft: false,
            // variantDumbbellEndRight: false,
            // variantDumbbellEndLeftRadius: null,
            // variantDumbbellEndRightRadius: null,
            // variantDumbbellEndRadius: 15,
            shadow: false,
            colors: ['#000'],
            textSize: 23,
            yaxisLinewidth: 3,
            yaxisTickmarks: false,
            yaxisLabelsOffsetx: -5,
            xaxis: false,
            xaxisScale: false,
            yaxis: false,
            backgroundGrid: false,
            xaxisLabelsCount: 4,
            marginLeftAuto: false,
            marginLeft: 200,
            marginTop: 15,
            marginBottom: 55,
            tooltips: ['Jim (b)','Berty (b)','Lois (b)','Cava (b)'],
            tooltipsOffsety: 10
        }
    }).grow();

    new RGraph.HBar({
        id: 'cvs',
        data: [[1,12],[6,12],[9,13],[1,10]],
        options: {
            variant: 'dumbbell',
            shadow: false,
            colors: ['red'],
            yaxis: false,
            xaxis: false,
            xaxisScale: false,
            backgroundGrid: false,
            marginLeftAuto: false,
            marginLeft: 200,
            marginTop: 55,
            marginBottom: 15,
            marginInner: 35,
            tooltips: ['Jim (r)','Berty (r)','Lois (r)','Cava (r)'],
            tooltipsOffsety: 10
        }
    }).grow();
</script>

Dumbbell variation for the Horizontal Bar chart