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/* Flot plugin that adds some extra symbols for plotting points.
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Copyright (c) 2007-2013 IOLA and Ole Laursen.
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Licensed under the MIT license.
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The symbols are accessed as strings through the standard symbol options:
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	series: {
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		points: {
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			symbol: "square" // or "diamond", "triangle", "cross"
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		}
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	}
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*/
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(function ($) {
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    function processRawData(plot, series, datapoints) {
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        // we normalize the area of each symbol so it is approximately the
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        // same as a circle of the given radius
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        var handlers = {
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            square: function (ctx, x, y, radius, shadow) {
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                // pi * r^2 = (2s)^2  =>  s = r * sqrt(pi)/2
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                var size = radius * Math.sqrt(Math.PI) / 2;
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                ctx.rect(x - size, y - size, size + size, size + size);
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            },
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            diamond: function (ctx, x, y, radius, shadow) {
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                // pi * r^2 = 2s^2  =>  s = r * sqrt(pi/2)
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                var size = radius * Math.sqrt(Math.PI / 2);
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                ctx.moveTo(x - size, y);
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                ctx.lineTo(x, y - size);
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                ctx.lineTo(x + size, y);
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                ctx.lineTo(x, y + size);
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                ctx.lineTo(x - size, y);
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            },
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            triangle: function (ctx, x, y, radius, shadow) {
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                // pi * r^2 = 1/2 * s^2 * sin (pi / 3)  =>  s = r * sqrt(2 * pi / sin(pi / 3))
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                var size = radius * Math.sqrt(2 * Math.PI / Math.sin(Math.PI / 3));
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                var height = size * Math.sin(Math.PI / 3);
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                ctx.moveTo(x - size/2, y + height/2);
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                ctx.lineTo(x + size/2, y + height/2);
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                if (!shadow) {
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                    ctx.lineTo(x, y - height/2);
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                    ctx.lineTo(x - size/2, y + height/2);
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                }
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            },
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            cross: function (ctx, x, y, radius, shadow) {
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                // pi * r^2 = (2s)^2  =>  s = r * sqrt(pi)/2
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                var size = radius * Math.sqrt(Math.PI) / 2;
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                ctx.moveTo(x - size, y - size);
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                ctx.lineTo(x + size, y + size);
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                ctx.moveTo(x - size, y + size);
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                ctx.lineTo(x + size, y - size);
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            }
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        };
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        var s = series.points.symbol;
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        if (handlers[s])
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            series.points.symbol = handlers[s];
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    }
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    function init(plot) {
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        plot.hooks.processDatapoints.push(processRawData);
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    }
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    $.plot.plugins.push({
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        init: init,
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        name: 'symbols',
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        version: '1.0'
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    });
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})(jQuery);
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