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 use for showing charts on your website.

More »


Get the latest version of RGraph (version 6.18, 1st June 2024) 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.

More »


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.

More »

The closePath function

The closePath function is used to mark the path you're drawing as closed so that you can begin another. It's important to remember that this function doesn't always need to be used - the deciding factor can be whether you want to draw a line back to the start point for the current path. Sometimes this isn't applicable though - such as when your path is only drawing a rectangle. In this case, the closePath might not be needed and you can just start a new path with the beginPath function - and not call closePath. In this case, the closePath is implied by starting a new path (but without drawing a connecting line to the start of the new path).

An example

    window.onload = function ()
        var canvas  = document.getElementById("cvs");
        var context = canvas.getContext('2d');

        context.arc(100,100, 50, 0, Math.PI, false);
        // This connects back to the start of the arc