RGraph is a JavaScript charts library based on HTML5 SVG and canvas. RGraph is mature (over 15 years old) and has a wealth of features making it an ideal choice to show charts on your website.

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RGraph can be used for free under the GPL or if that doesn't suit your situation there's an inexpensive (£99) commercial license available.

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Get the latest version of RGraph (version 6.16) from the download page. There's also older versions available, minified files and links to cdnjs.com hosted libraries.

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HOWTO: Get rounded corners on a Bar chart

View example on CodePen

This page previously detailed how to get rounded corners on your Bar chart. This involved a lot of code and necessitated you to redefine the canvas rect api function.

Now, however, there's a corners option for the Bar chart which does everything for you. Animations are no problem either.

Here's the source code for the chart shown here which demonstrates the corners option. There's also a cornersRoundRadius option as well which allows you to control the extent of the rounding effect.

    new RGraph.Bar({
        id: 'cvs',
        data: [12,13,16,15,16,19,19,12,23,16,13,24],
        options: {
            marginTop: 35,
            marginLeft: 55,
            title: 'Percentage of goods sold',
            titleSize: 16,
            titleBold: true,
            xaxisLabels: ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'],
            _months: ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'],
            tooltips: '%{property:_months[%{dataset}]}: %{value}%',
            tooltipsCss: {
                fontSize: '20pt'
            backgroundGridVlines: false,
            backgroundGridBorder: false,
            xaxis: false,
            yaxis: false,
            yaxisScaleUnitsPost: '%',
            colors: ['Gradient(#c33:red:red:red)'],
            textSize: 16,
            corners: 'round',
            cornersRoundRadius: 50