1 /* Flot plugin for thresholding data.

     2 

     3 Copyright (c) 2007-2014 IOLA and Ole Laursen.

     4 Licensed under the MIT license.

     5 

     6 The plugin supports these options:

     7 

     8     series: {

     9         threshold: {

    10             below: number

    11             color: colorspec

    12         }

    13     }

    14 

    15 It can also be applied to a single series, like this:

    16 

    17     $.plot( $("#placeholder"), [{

    18         data: [ ... ],

    19         threshold: { ... }

    20     }])

    21 

    22 An array can be passed for multiple thresholding, like this:

    23 

    24     threshold: [{

    25         below: number1

    26         color: color1

    27     },{

    28         below: number2

    29         color: color2

    30     }]

    31 

    32 These multiple threshold objects can be passed in any order since they are

    33 sorted by the processing function.

    34 

    35 The data points below "below" are drawn with the specified color. This makes

    36 it easy to mark points below 0, e.g. for budget data.

    37 

    38 Internally, the plugin works by splitting the data into two series, above and

    39 below the threshold. The extra series below the threshold will have its label

    40 cleared and the special "originSeries" attribute set to the original series.

    41 You may need to check for this in hover events.

    42 

    43 */

    44 

    45 (function ($) {

    46     var options = {

    47         series: { threshold: null } // or { below: number, color: color spec}

    48     };

    49 

    50     function init(plot) {

    51         function thresholdData(plot, s, datapoints, below, color) {

    52             var ps = datapoints.pointsize, i, x, y, p, prevp,

    53                 thresholded = $.extend({}, s); // note: shallow copy

    54 

    55             thresholded.datapoints = { points: [], pointsize: ps, format: datapoints.format };

    56             thresholded.label = null;

    57             thresholded.color = color;

    58             thresholded.threshold = null;

    59             thresholded.originSeries = s;

    60             thresholded.data = [];

    61 

    62             var origpoints = datapoints.points,

    63                 addCrossingPoints = s.lines.show;

    64 

    65             var threspoints = [];

    66             var newpoints = [];

    67             var m;

    68 

    69             for (i = 0; i < origpoints.length; i += ps) {

    70                 x = origpoints[i];

    71                 y = origpoints[i + 1];

    72 

    73                 prevp = p;

    74                 if (y < below) p = threspoints;

    75                 else p = newpoints;

    76 

    77                 if (addCrossingPoints && prevp !== p &&

    78                     x !== null && i > 0 &&

    79                     origpoints[i - ps] != null) {

    80                     var interx = x + (below - y) * (x - origpoints[i - ps]) / (y - origpoints[i - ps + 1]);

    81                     prevp.push(interx);

    82                     prevp.push(below);

    83                     for (m = 2; m < ps; ++m) {

    84                         prevp.push(origpoints[i + m]);

    85                     }

    86 

    87                     p.push(null); // start new segment

    88                     p.push(null);

    89                     for (m = 2; m < ps; ++m) {

    90                         p.push(origpoints[i + m]);

    91                     }

    92 

    93                     p.push(interx);

    94                     p.push(below);

    95                     for (m = 2; m < ps; ++m) {

    96                         p.push(origpoints[i + m]);

    97                     }

    98                 }

    99 

   100                 p.push(x);

   101                 p.push(y);

   102                 for (m = 2; m < ps; ++m) {

   103                     p.push(origpoints[i + m]);

   104                 }

   105             }

   106 

   107             datapoints.points = newpoints;

   108             thresholded.datapoints.points = threspoints;

   109 

   110             if (thresholded.datapoints.points.length > 0) {

   111                 var origIndex = $.inArray(s, plot.getData());

   112                 // Insert newly-generated series right after original one (to prevent it from becoming top-most)

   113                 plot.getData().splice(origIndex + 1, 0, thresholded);

   114             }

   115 

   116             // FIXME: there are probably some edge cases left in bars

   117         }

   118 

   119         function processThresholds(plot, s, datapoints) {

   120             if (!s.threshold) return;

   121             if (s.threshold instanceof Array) {

   122                 s.threshold.sort(function(a, b) {

   123                     return a.below - b.below;

   124                 });

   125 

   126                 $(s.threshold).each(function(i, th) {

   127                     thresholdData(plot, s, datapoints, th.below, th.color);

   128                 });

   129             } else {

   130                 thresholdData(plot, s, datapoints, s.threshold.below, s.threshold.color);

   131             }

   132         }

   133 

   134         plot.hooks.processDatapoints.push(processThresholds);

   135     }

   136 

   137     $.plot.plugins.push({

   138         init: init,

   139         options: options,

   140         name: 'threshold',

   141         version: '1.2'

   142     });

   143 })(jQuery);