A spline range Line chart

This range chart is a little different from the others as the datasets are organised a little differently. The first dataset that you give to the Line chart becomes the bottom dataset and is an absolute set of values - in the example here the first number is 4.

The second dataset, which is the top line, is additive/accumulative. In this case the first point of the second dataset is 1. So added to the first point of the first dataset (which was 4) you get a total of 5 - which is the figure that is shown on the chart.

The reason for this is because the spline range chart is really a stacked spline chart - but with the bottom dataset using transparent as its color - so you can't see it.

This is shown below by gradually changing the color of the "bottom" dataset from blue to transparent.

[No canvas support]

This goes in the documents header:
<script src="RGraph.common.core.js"></script>
<script src="RGraph.line.js"></script>
Put this where you want the chart to show up:
<canvas id="cvs" width="600" height="250">
    [No canvas support]
</canvas>
This is the code that generates the chart:
<script>
    window.onload = function ()
    {
        var opacity = 1;
       
        var line = new RGraph.Line({
            id: 'cvs',
            data: [
                [4,6,16,15,13,14,18,15,18,16],
                [1,1,1,2,3,5,9,9,6,3]
            ],
            options: {
                spline: true,
                filled: true,
                colors: ['red'],
                shadow: false,
                fillstyle: ['rgba(0,0,255,1)','#fdd'],
                labels: ['a','b','c','d','e','f','g','h','i','j'],
                numxticks: 9,
                tickmarks: null,
                gutterBottom: 35,
                textSize:14,
                backgroundGridVlines: false,
                backgroundGridBorder: false,
                noxaxis: true,
                textAccessible: true
            }
        }).draw();


        for (var i=100; i>=0; i-=1) {
            (function (idx)
            {
                var opacity = i * 0.01;
                setTimeout(function () {line.set('fillstyle', ['rgba(0,0,255,' + opacity + ')','#fdd']); RGraph.redraw();}, (10 - idx) * 20);
            })(i);
        }
    };
</script>