tests/multi-scale.html

   1 <!DOCTYPE html>
   2 <html>
   3   <head>
   4     <meta http-equiv="X-UA-Compatible" content="IE=EmulateIE7; IE=EmulateIE9">
   5     <title>multi-scale</title>
   6     <!--[if IE]>
   7     <script type="text/javascript" src="../excanvas.js"></script>
   8     <![endif]-->
   9     <script type="text/javascript" src="../dygraph-dev.js"></script>
  10   </head>
  11   <body style="max-width: 700px;">
  12     <p>Gridlines and axis labels make charts easier to understand. They give
  13     the lines a clear scale. Unless you tell it otherwise, dygraphs will choose
  14     a y-axis and set of gridlines which include all of your data.</p>
  15
  16     <p>If you have many series with different scales, this will compress the
  17     variation in all but the largest one. Standard ways to deal with this
  18     include <a href="two-axes.html">secondary y-axes</a> and <a
  19     href="logscale.html">log scales</a>.</p>
  20
  21     <p>If neither of these is to your liking, you can manually rescale your
  22     series and undo that scaling for the hover values. This demo shows how to
  23     do it.</p>
  24
  25     <div id="demodiv"></div>
  26
  27     <p>Hover over to see the original values. This is what the data looks
  28     like without any rescaling:</p>
  29
  30     <div id="reference_div"></div>
  31
  32     <script type="text/javascript">
  33       var zp = function(x) { if (x < 10) return "0"+x; else return x; };
  34       var labels = ["date","parabola","line","another line","sine wave"];
  35       var data = [];
  36       for (var i=1; i<=31; i++) {
  37         var row = [];
  38         row.push(new Date("2006/10/" + zp(i)));
  39         row.push(10*(i*(31-i)));
  40         row.push(100*(8*i));
  41         row.push(1000*(250 - 8*i));
  42         row.push(10000*(125 + 125 * Math.sin(0.3*i)));
  43         data.push(row);
  44       }
  45
  46       var scales = {
  47         "parabola": 1,
  48         "line": 10,
  49         "another line": 100,
  50         "sine wave": 1000
  51       };
  52       var rescaled_data = [];
  53       for (var i = 0; i < data.length; i++) {
  54         var src = data[i];
  55         var row = [];
  56         row.push(src[0]);
  57         for (var j = 1; j < src.length; j++) {
  58           row.push(src[j] / scales[labels[j]]);
  59         }
  60         rescaled_data.push(row);
  61       }
  62
  63       g = new Dygraph(
  64               document.getElementById("demodiv"),
  65               rescaled_data,
  66               {
  67                 legend: 'always',
  68                 labels: labels,
  69                 width: 640,
  70                 height: 480,
  71                 title: 'Four series on different scales',
  72                 xlabel: 'Date',
  73                 ylabel: 'Count',
  74                 yValueFormatter: function(y, opts, series_name) {
  75                   var unscaled = y * scales[series_name];
  76                   if (series_name == 'sine wave') return unscaled.toPrecision(4);
  77                   return unscaled;
  78                 }
  79               }
  80           );
  81
  82       g_orig = new Dygraph(
  83               document.getElementById("reference_div"),
  84               data,
  85               {
  86                 legend: 'always',
  87                 labels: labels,
  88                 width: 640,
  89                 height: 480,
  90                 title: 'Four series on the same scale',
  91                 xlabel: 'Date',
  92                 ylabel: 'Count',
  93                 yAxisLabelWidth: 80
  94               }
  95           );
  96     </script>
  97 </body>
  98 </html>