An (adjustable) image based Meter chart

This goes in the documents header:

<script src="RGraph.common.core.js"></script>
<script src="RGraph.common.dynamic.js"></script>
<script src="RGraph.meter.js"></script>

Put this where you want the chart to show up:

<canvas id="cvs" id="cvs" width="237" height="196">
    [No canvas support]
</canvas>

This is the code that generates the chart:

<script>
    var meter = new RGraph.Meter({
        id: 'cvs',
        min: 0,
        max: 70,
        value: 64,
        options: {
            centerx: 150,
            centery: 150,
            backgroundColor: 'rgba(0,0,0,0)',
            backgroundImageUrl: '/images/shiny-meter.png',
            backgroundImageStretch: false,
            backgroundImageOffsetx: -1,
            backgroundImageOffsety: -1,
            needleColor: 'rgba(0,0,0,0)',
            needleImageUrl: '/images/meter-needle-big-red.png',
            needleImageOffsetx: -25,
            needleImageOffsety: -18,
            colorsRanges: [],
            tickmarksBigNum: 0,
            tickmarksSmallNum: 0,
            border: false,
            labels: false,
            centerpinStroke: 'rgba(0,0,0,0)',
            centerpinFill: 'rgba(0,0,0,0)',
            anglesStart: 2.38,
            anglesEnd: 7.05
        }
    }).draw();
    
    meter.canvas.onclick = function (e)
    {
        var value = meter.getValue(e);
    
        if (typeof value === 'number') {
            meter.value = value;
            meter.grow();
        }
    }
</script>