# A bar chart with horizontal gradients

This bar chart draws the chart then uses the coordinates of the bars to create gradients (each is specific to a bar), changes the colors to the gradients and finally redraws the chart.

This goes in the documents header:

    <script src="RGraph.common.core.js"></script>
    <script src="RGraph.common.dynamic.js"></script>
    <script src="RGraph.bar.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 bar = new RGraph.Bar({
                id: 'cvs',
                data: [4,8,5,3,4,6,8],
                options: {
                    labels: ['Mon','Tue','Wed','Thu','Fri','Sat','Sun'],
                    colorsSequential: true,
                    shadow: true,
                    shadowColor: '#999',
                    shadowOffsetx: 0,
                    shadowOffsety: 0,
                    shadowBlur: 15,
                    strokestyle: 'rgba(0,0,0,0)',
                    backgroundGridAutofitNumvlines: 7,
                    noyaxis: true,
                    textAccessible: true
                }
            }).draw()

            /**
            * Now the chart has been drawn use the coords to create some appropriate gradients
            */
            var colors = [];

            for(var i=0; i<bar.coords.length; ++i) {
                // Because it's a horizontal gradient the Y coords don't matter
                var x1 = bar.coords[i][0];
                var y1 = 0;
                var x2 = bar.coords[i][0] + bar.coords[i][2];
                var y2 = 0;

                colors[i] = RGraph.linearGradient(bar, x1, y1, x2, y2, '#c00','red');
            }

            bar.set('colors', colors);
            RGraph.clear(bar.canvas);
            RGraph.redraw();
        };
    </script>