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   4     <title>dygraphs JavaScript Visualization Library</title>
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   8     <script type="text/javascript" src="dygraph-combined.js"></script>
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  13       <h2>Documentation</h2>
  14       <ul>
  15         <li><a href="#demo">Demo</a></li>
  16         <li><a href="#usage">Usage</a></li>
  17         <li><a href="#ie">IE Compatibility</a></li>
  18         <li><a href="#gviz">GViz Data</a></li>
  19         <li><a href="#baseball">Baseball chart</a></li>
  20         <li><a href="#stock">Stock chart</a></li>
  21         <li><a href="#options">Options Reference</a></li>
  22         <li><a href="#gwt">GWT Compatibility</a></li>
  23         <li><a href="#policy">Data Policy</a></li>
  24       </ul>
  25
  26       <h2>Features</h2>
  27       <ul>
  28         <li><a href="data.html">Data Formats</a></li>
  29         <li><a href="annotations.html">Annotations</a></li>
  30       </ul>
  31
  32       <h2>Project</h2>
  33       <ul>
  34         <li><a href="http://github.com/danvk/dygraphs">Source</a></li>
  35         <li><a href="http://code.google.com/p/dygraphs/issues/">Issues</a></li>
  36         <li><a href="http://code.google.com/p/dygraphs/issues/entry">Report Bug</a></li>
  37         <li><a href="changes.html">Contribute a change</a></li>
  38         <li><a href="mailto:dygraphs-users [at] googlegroups.com">Contact</a></li>
  39       </ul>
  40
  41       <h2>Gallery</h2>
  42       <ul>
  43         <li><a href="tests/">(browse demos)</a></li>
  44         <li><a href="tests/demo.html">Basic Demo</a></li>
  45         <li><a href="tests/gviz.html">GViz Demo</a></li>
  46         <li><a href="tests/plotter.html">Equation Plotter</a></li>
  47         <li><a href="tests/perf.html">Performance Test</a></li>
  48         <li><a href="tests/annotation.html">Annotations</a></li>
  49         <li><a href="tests/annotation-gviz.html">Annotations (GViz)</a></li>
  50         <li><a href="tests/fillGraph.html">Filled Chart</a></li>
  51         <li><a href="tests/perf.html">Fractions</a></li>
  52         <li><a href="tests/visibility.html">Visibility</a></li>
  53         <li><a href="tests/label-div.html">Labels in a DIV</a></li>
  54         <li><a href="tests/numeric-axis.html">Numeric Axis</a></li>
  55         <li><a href="tests/draw-points.html">Dotted Points</a></li>
  56         <li><a href="tests/native-format.html">Native Format</a></li>
  57         <li><a href="tests/grid_dot.html">Crazy Styles</a></li>
  58         <li><a href="tests/spacing.html">Tick spacing</a></li>
  59         <li><a href="tests/callback.html">Callbacks</a></li>
  60         <li><a href="tests/crosshair.html">Crosshairs</a></li>
  61         <li><a href="tests/hourly.html">Hourly/Minutely data</a></li>
  62         <li><a href="tests/isolated-points.html">Isolated Points</a></li>
  63         <li><a href="tests/missing-data.html">Missing Data</a></li>
  64         <li><a href="tests/border.html">Bordered chart</a></li>
  65         <li><a href="tests/custom-bars.html">Custom Bars</a></li>
  66         <li><a href="tests/customLabel.html">Custom Label Styles</a></li>
  67         <li><a href="tests/dygraph.html">Minimal Example</a></li>
  68         <li><a href="tests/negative.html">Negative Numbers</a></li>
  69         <li><a href="tests/noise.html">Noisy Data</a></li>
  70         <li><a href="tests/two-series.html">Multiple Series</a></li>
  71         <li><a href="tests/highlighted-region.html">Custom Underlay / background</a></li>
  72         <li><a href="tests/zoom.html">Tests for zoom operations</a></li>
  73         <li><a href="tests/logscale.html">Log scale tests</a></li>
  74       </ul>
  75     </div>
  76
  77     <div id="content">
  78       <h1>dygraphs JavaScript Visualization Library</h1>
  79
  80       <p><a href="http://github.com/danvk/dygraphs">http://github.com/danvk/dygraphs</a></p>
  81       <p>See <a href="http://groups.google.com/group/dygraphs-users">mailing list</a>, <a href="http://github.com/danvk/dygraphs/downloads/">downloads</a>, <a href="tests/">gallery</a> and <a href="http://code.google.com/p/dygraphs/issues/">open issues</a></p>
  82
  83       <p>dygraphs is an open source JavaScript library that produces produces interactive, zoomable charts of time series. It is designed to display dense data sets and enable users to explore and interpret them.</p>
  84
  85       <h3 id="demo">A demo is worth a thousand words:</h3>
  86
  87       <p style="font-size:0.8em">(Mouse over to highlight individual values. Click and drag to zoom. Double-click to zoom back out. Change the number and hit enter to adjust the averaging period.)</p>
  88
  89       <div id="title" style="width:800px; margin: 1em;text-align:center; font-weight: bold; font-size: 125%;">Temperatures in New York vs. San Francisco</div>
  90
  91       <div id="demodiv" style="width:800px; height:320px;"></div>
  92       <script type="text/javascript">
  93         g = new Dygraph(
  94           document.getElementById("demodiv"),
  95           "ny-vs-sf.txt",
  96           {
  97             rollPeriod: 14,
  98             showRoller: true,
  99             customBars: true,
 100             yAxisLabelWidth: 30
 101           }
 102         );
 103       </script>
 104
 105       <h4>Some things to notice:</h4>
 106       <ul>
 107         <li>There's less seasonal temperature variation in SF than in NY.</li>
 108         <li>The difference is about 15&deg; F for SF vs. 50&deg; F for NY.</li>
 109         <li>The daily data (set rolling period to 1) is quite noisy and hides this conclusion.</li>
 110         <li>Using a 14-day moving average makes it clearer. A 100-day rolling period averages out nearly all the specifics from the data.</li>
 111         <li>There's a gap in the data for SF, when the weather station was down (zoom into October 2007 to see it).</li>
 112         <li>The bands around each point indicate average highs and lows.</li>
 113         <li>There is a <em>lot</em> of data in this chart: low, average and high for each city on each day of a three year period &asymp; 6000 data points in all.</li>
 114       </ul>
 115
 116       <p>dygraphs allows the user to explore the data and discover these facts.</p>
 117
 118       <p>For more demos, browse the dygraph <a href="tests/">tests</a> directory.</p>
 119
 120       <h3>Features</h3>
 121       <p>Some of the features of dygraphs:</p>
 122       <ul>
 123         <li>Plots time series without using an external server or Flash</li>
 124         <li>Works in Internet Explorer (using excanvas)</li>
 125         <li>Lightweight (69kb) and responsive</li>
 126         <li>Displays values on mouseover (this makes it easily discoverable)</li>
 127         <li>Supports error bands around data series</li>
 128         <li>Interactive zoom</li>
 129         <li>Displays Annotations on the chart</li>
 130         <li>Adjustable averaging period</li>
 131         <li>Can intelligently chart fractions</li>
 132         <li>Customizable click-through actions</li>
 133         <li>Compatible with the Google Visualization API</li>
 134         <li>Intelligent defaults make it easy to use</li>
 135       </ul>
 136
 137       <h2 id="usage">Usage</h2>
 138
 139       <p>To use dygraphs, include the <code><a href="http://github.com/danvk/dygraphs/downloads/">dygraph-combined.js</a></code> JavaScript file and instantiate a <code>Dygraph</code> object.</p>
 140
 141       <p>Here's a basic example to get things started:</p>
 142
 143       <div class="example" style="clear:both;">
 144         <div class="codeblock" style="float:left;width:400px;">
 145           <h3 style="text-align:center">HTML</h3>
 146           <code>
 147   <pre>
 148 &lt;html&gt;
 149 &lt;head&gt;
 150 &lt;script type=&quot;text/javascript&quot;
 151   src=&quot;dygraph-combined.js&quot;&gt;&lt;/script&gt;
 152 &lt;/head&gt;
 153 &lt;body&gt;
 154 &lt;div id=&quot;graphdiv&quot;&gt;&lt;/div&gt;
 155 &lt;script type=&quot;text/javascript&quot;&gt;
 156   g = new Dygraph(
 157
 158     // containing div
 159     document.getElementById(&quot;graphdiv&quot;),
 160
 161     // CSV or path to a CSV file.
 162     &quot;Date,Temperature\n&quot; +
 163     &quot;2008-05-07,75\n&quot; +
 164     &quot;2008-05-08,70\n&quot; +
 165     &quot;2008-05-09,80\n&quot;
 166
 167   );
 168 &lt;/script&gt;
 169 &lt;/body&gt;
 170 &lt;/html&gt;
 171 </pre>
 172           </code>
 173         </div>
 174         <div class="codeoutput" style="float:left;">
 175           <h3 style="text-align:center">OUTPUT</h3>
 176           <div id="graphdiv"></div>
 177           <script type="text/javascript">
 178             g = new Dygraph(
 179
 180               // containing div
 181               document.getElementById("graphdiv"),
 182
 183               // CSV or path to a CSV file.
 184               "Date,Temperature\n" +
 185               "2008-05-07,75\n" +
 186               "2008-05-08,70\n" +
 187               "2008-05-09,80\n"
 188             );
 189           </script>
 190         </div>
 191       </div>
 192
 193       <p style="clear:both">In order to keep this example self-contained, the second parameter is raw CSV data. The dygraphs library parses this data (including column headers), resizes its container to a reasonable default, calculates appropriate axis ranges and tick marks and draws the graph.</p>
 194
 195       <p>In most applications, it makes more sense to include a CSV file instead. If the second parameter to the constructor doesn't contain a newline, it will be interpreted as the path to a CSV file. The Dygraph will perform an XMLHttpRequest to retrieve this file and display the data when it becomes available. Make sure your CSV file is readable and serving from a place that understands XMLHttpRequest's! In particular, you cannot specify a CSV file using <code>"file:///"</code>. Here's an example: (data from <a href="http://www.wunderground.com/history/airport/KNUQ/2007/1/1/CustomHistory.html?dayend=31&amp;monthend=12&amp;yearend=2007&amp;req_city=NA&amp;req_state=NA&amp;req_statename=NA">Weather Underground</a>)</p>
 196
 197       <div class="example" style="clear:both;">
 198         <div class="codeblock" style="float:left;width:400px;">
 199           <h3 style="text-align:center">HTML</h3>
 200           <code>
 201 <pre>
 202 &lt;html&gt;
 203 &lt;head&gt;
 204 &lt;script type=&quot;text/javascript&quot;
 205   src=&quot;dygraph-combined.js&quot;&gt;&lt;/script&gt;
 206 &lt;/head&gt;
 207 &lt;body&gt;
 208 &lt;div id=&quot;graphdiv2&quot;
 209   style=&quot;width:500px; height:300px;&quot;&gt;&lt;/div&gt;
 210 &lt;script type=&quot;text/javascript&quot;&gt;
 211   g2 = new Dygraph(
 212     document.getElementById(&quot;graphdiv2&quot;),
 213     &quot;temperatures.csv&quot;, // path to CSV file
 214     {}          // options
 215   );
 216 &lt;/script&gt;
 217 &lt;/body&gt;
 218 &lt;/html&gt;
 219 </pre>
 220           </code>
 221         </div>
 222         <div class="codeoutput" style="float:left;">
 223           <h3 style="text-align:center">OUTPUT</h3>
 224           <div id="graphdiv2" style="width:500px; height:300px;"></div>
 225           <script type="text/javascript">
 226             g2 = new Dygraph(
 227               document.getElementById("graphdiv2"),
 228               "temperatures.csv",
 229               {}
 230             );
 231           </script>
 232         </div>
 233       </div>
 234
 235       <p style="clear:both;">The file used is <code><a href="temperatures.csv">temperatures.csv</a></code>.</p>
 236
 237       <p>There are a few things to note here:</p>
 238
 239       <ul>
 240         <li>The Dygraph sent off an XHR to get the temperatures.csv file.</li>
 241         <li>The labels were taken from the first line of <code>temperatures.csv</code>, which is <code>Date,High,Low</code>.</li>
 242         <li>The Dygraph automatically chose two different, easily-distinguishable colors for the two data series.</li>
 243         <li>The labels on the x-axis have switched from days to months. If you zoom in, they'll switch to weeks and then days.</li>
 244         <li>Some heuristics are used to determine a good vertical range for the data. The idea is to make all the data visible and have human-friendly values on the axis (i.e. 200 instead of 193.4). Generally this works well.</li>
 245         <li>The data is very spiky. A moving average would be easier to interpret.</li>
 246       </ul>
 247
 248       <p>This problem can be fixed by specifying the appropriate options in the "additional options" parameter to the Dygraph constructor. To set the number of days for a moving average, use the <code>rollPeriod</code> option. Here's how it's done:</p>
 249
 250       <div class="example" style="clear:both;">
 251         <div class="codeblock" style="float:left;width:400px;">
 252           <h3 style="text-align:center">HTML</h3>
 253           <code>
 254 <pre>
 255 &lt;html&gt;
 256 &lt;head&gt;
 257 &lt;script type=&quot;text/javascript&quot;
 258   src=&quot;dygraph-combined.js&quot;&gt;&lt;/script&gt;
 259 &lt;/head&gt;
 260 &lt;body&gt;
 261 &lt;div id=&quot;graphdiv3&quot;
 262   style=&quot;width:500px; height:300px;&quot;&gt;&lt;/div&gt;
 263 &lt;script type=&quot;text/javascript&quot;&gt;
 264   g3 = new Dygraph(
 265     document.getElementById(&quot;graphdiv3&quot;),
 266     &quot;temperatures.csv&quot;,
 267     {
 268       rollPeriod: 7,
 269       showRoller: true
 270     }
 271   );
 272 &lt;/script&gt;
 273 &lt;/body&gt;
 274 &lt;/html&gt;
 275 </pre>
 276           </code>
 277         </div>
 278         <div class="codeoutput" style="float:left;">
 279           <h3 style="text-align:center">OUTPUT</h3>
 280           <div id="graphdiv3" style="width:500px; height:300px;"></div>
 281           <script type="text/javascript">
 282             g3 = new Dygraph(
 283               document.getElementById("graphdiv3"),
 284               "temperatures.csv",
 285               {
 286                 rollPeriod: 7,
 287                 showRoller: true
 288               }
 289             );
 290           </script>
 291         </div>
 292       </div>
 293
 294       <p style="clear:both;">A rolling average can be set using the text box in the lower left-hand corner of the graph (the showRoller attribute is what makes this appear). Also note that we've explicitly set the size of the chart div.</p>
 295
 296       <h2>Error Bars</h2>
 297
 298       <p>Another significant feature of the dygraphs library is the ability to display error bars around data series. One standard deviation must be specified for each data point. A <em>&plusmn;n</em> sigma band will be drawn around the data series at that point. If a moving average is being displayed, dygraphs will compute the standard deviation of the average at each point. I.E. <em>&sigma; = sqrt( (&sigma;<sub>1<sup>2</sup></sub> + &sigma;<sub>2<sup>2</sup></sub> + ... + &sigma;<sub>n<sup>2</sup></sub>) / n )</em></p>
 299
 300       <p>Here's a demonstration. There are two data series. One is <code>N(100,10)</code> with a standard deviation of 10 specified at each point. The other is <code>N(80,20)</code> with a standard deviation of 20 specified at each point. The CSV file was generated using Octave and can be viewed at <a href="twonormals.csv">twonormals.csv</a>.</p>
 301
 302       <div class="example" style="clear:both;">
 303         <div class="codeblock" style="float:left;width:400px;">
 304           <h3 style="text-align:center">HTML</h3>
 305           <code>
 306 <pre>
 307 &lt;html&gt;
 308 &lt;head&gt;
 309 &lt;script type=&quot;text/javascript&quot;
 310   src=&quot;combined.js&quot;&gt;&lt;/script&gt;
 311 &lt;/head&gt;
 312 &lt;body&gt;
 313 &lt;div id=&quot;graphdiv4&quot;
 314   style=&quot;width:600px; height:300px;&quot;&gt;&lt;/div&gt;
 315 &lt;script type=&quot;text/javascript&quot;&gt;
 316   g4 = new Dygraph(
 317     document.getElementById(&quot;graphdiv4&quot;),
 318     &quot;twonormals.csv&quot;,
 319     {
 320       rollPeriod: 7,
 321       showRoller: true,
 322       errorBars: true,
 323       valueRange: [50,125]
 324     }
 325   );
 326 &lt;/script&gt;
 327 &lt;/body&gt;
 328 &lt;/html&gt;
 329 </pre>
 330           </code>
 331         </div>
 332         <div class="codeoutput" style="float:left;">
 333           <h3 style="text-align:center">OUTPUT</h3>
 334           <div id="graphdiv4" style="width:600px; height:300px;"></div>
 335           <script type="text/javascript">
 336             g4 = new Dygraph(
 337               document.getElementById("graphdiv4"),
 338               "twonormals.csv",
 339               {
 340                 rollPeriod: 7,
 341                 showRoller: true,
 342                 errorBars: true,
 343                 valueRange: [50,125]
 344               }
 345             );
 346           </script>
 347         </div>
 348       </div>
 349
 350       <p style="clear:both;">Things to note here:</p>
 351
 352       <ul>
 353         <li>The <strong>errorBars</strong> option affects both the interpretation of the CSV file and the display of the graph. When <strong>errorBars</strong> is set to true, each line is interpreted as <em>YYYYMMDD</em>, <em>A</em>, <em>sigma_A</em>, <em>B</em>, <em>sigma_B</em>, &hellip;</li>
 354         <li>The first line of the CSV file doesn't mention the error columns. In this case, it's just "Date,Series1,Series2".</li>
 355         <li>The averaging visibly affects the error bars. This is most clear if you crank up the rolling period to something like 100 days. For the earliest dates, there won't be 100 data points to average so the signal will be noisier. The error bars get smaller like sqrt(N) going forward in time until there's a full 100 points to average.</li>
 356         <li>The error bars are partially transparent. This can be seen when they overlap one another.</li>
 357       </ul>
 358
 359       <h2 id="ie">Internet Explorer Compatibility</h2>
 360
 361       <p>The dygraphs library relies heavily on the HTML5 <code>&lt;canvas&gt;</code> tag, which Microsoft Internet Explorer did not traditionally support. To use Microsoft's native canvas implementation in IE9, you need to set an HTML5 doctype on your page:</p>
 362
 363       <pre>
 364       &lt;!DOCTYPE html&gt;
 365       </pre>
 366
 367       <p>When IE9 is in HTML5 mode, dygraphs works just like in other modern browsers.</p>
 368
 369       <p>If you want to support previous versions of Internet Explorer (IE6&ndash;IE8), you'll need to include the <a href="http://code.google.com/p/explorercanvas/">excanvas</a> library, which emulates the <code>&lt;canvas&gt;</code> tag using VML. You can add excanvas by including this snippet:</p>
 370
 371 <pre>
 372 &lt;head&gt;
 373   &lt;!--[if IE]&gt;&lt;script src="excanvas.js"&gt;&lt;/script&gt;&lt;![endif]--&gt;
 374 &lt;/head&gt;
 375 </pre>
 376
 377     <p>While this sounds like it would be slow, it works well in practice for most charts.</p>
 378
 379     <p>One common gotcha to look out for: make sure you don't have any trailing commas in parameter lists, e.g.</p>
 380
 381 <pre>
 382 new Dygraph(el, data, {
 383   showRoller: true,  // note trailing comma
 384 })</pre>
 385
 386     <p>Most browsers will ignore the trailing comma, but it will break under IE.</p>
 387
 388     <h2 id="gviz">GViz Data</h2>
 389
 390     <p>The <a
 391       href="http://code.google.com/apis/visualization/documentation/index.html">Google
 392       Visualization API</a> provides a standard interface for describing data.
 393     Once you've specified your data using this API, you can plug in any
 394     GViz-compatible visualization. dygraphs is such a visualization. In
 395     particular, it can be used as a drop-in replacement for the
 396     AnnotatedTimeline visualization used on Google Finance and other sites. To
 397     see how this works, check out the <a href="tests/annotation-gviz.html">gviz
 398       annotation demo.</a></p>
 399
 400     <p>For a simple demonstration of how to use dygraphs a GViz visualization, see <a href="http://danvk.org/dygraphs/tests/gviz.html">http://danvk.org/dygraphs/tests/gviz.html</a>. dygraphs can also be used as a GViz gadget. This allows it to be embedded inside of a Google Spreadsheet. For a demonstration of this, see <a   href="http://spreadsheets.google.com/ccc?key=0Anx1yCqeL8YUdDR1c3pPREhraGhkWmdhaURjOXRncXc&amp;hl=en">this spreadsheet</a>. The URL for the gadget is <code><a href="http://danvk.org/dygraphs/gadget.xml">http://danvk.org/dygraphs/gadget.xml</a></code>.</p>
 401
 402     <p>Here's an example of a published gviz gadget using dygraphs:</p>
 403
 404     <script src="http://spreadsheets.google.com/gpub?url=http%3A%2F%2Fkb8jbn8l90ocl9n4b14jrcvp61ceqis5.spreadsheets.gmodules.com%2Fgadgets%2Fifr%3Fup__table_query_url%3Dhttp%253A%252F%252Fspreadsheets.google.com%252Ftq%253Frange%253DA1%25253AC31%2526headers%253D-1%2526key%253D0Anx1yCqeL8YUdDR1c3pPREhraGhkWmdhaURjOXRncXc%2526gid%253D0%2526pub%253D1%26up__table_query_refresh_interval%3D300%26url%3Dhttp%253A%252F%252Fdanvk.org%252Fdygraphs%252Fgadget.xml%253Fnocache&height=215&width=530"></script>
 405
 406     <h2 id="baseball">Charting Fractions</h2>
 407
 408     <p>Situations often arise where you want to plot fractions, e.g. the fraction of respondents in a poll who said they'd vote for candidate X or the number of hits divided by at bats (baseball's batting average). Fractions require special treatment for two main reasons:</p>
 409
 410     <ul>
 411       <li>The average of <code>a1/b1</code> and <code>a2/b2</code> is <code>(a1+a2)/(b1+b2)</code>, not <code>(a1/b1 + a2/b2)/2</code>.</li>
 412       <li>The normal approximation is not always applicable and more sophisticated confidence intervals (e.g. the <a href="http://en.wikipedia.org/wiki/Binomial_proportion_confidence_interval">Wilson confidence interval</a>) must be employed to avoid ratios that exceed 100% or go below 0%.</li>
 413     </ul>
 414
 415     <p>Fortunately, dygraphs handles both of these for you! Here's a chart and the command that generated it:</p>
 416
 417     <div style="width:750px; text-align:center; font-weight: bold; font-size: 125%;">Batting Average for Ichiro Suzuki vs. Mariners (2004)</div>
 418     <div id="baseballdiv" style="width:750px; height:300px;"></div>
 419     <script type="text/javascript">
 420       new Dygraph(
 421         document.getElementById("baseballdiv"),
 422         "suzuki-mariners.txt",
 423         {
 424           fractions: true,
 425           errorBars: true,
 426           showRoller: true,
 427           rollPeriod: 15
 428         }
 429       );
 430     </script>
 431
 432     <p>Command:</p>
 433 <pre>
 434   new Dygraph(
 435     document.getElementById(&quot;baseballdiv&quot;),
 436     &quot;suzuki-mariners.txt&quot;,
 437     {
 438       fractions: true,
 439       errorBars: true,
 440       showRoller: true,
 441       rollPeriod: 15
 442     }
 443   );
 444 </pre>
 445
 446     <p>The <code>fractions</code> option indicates that the values in each column should be parsed as fractions (e.g. "1/2" instead of "0.5"). The <code>errorBars</code> option indicates that we'd like to see a confidence interval around each data point. By default, when <code>fractions</code> is set, you get a Wilson confidence interval. If you look carefully at the chart, you can see that the error bars are asymmetric.</p>
 447
 448     <p>A couple things to notice about this chart:</p>
 449
 450     <ul>
 451       <li>The error bars for Ichiro's batting average are larger than for the Mariners', since he has far fewer at bats than his team.</li>
 452       <li>dygraphs makes it easy to see "batting average over the last 30 games". This is ordinarily quite difficult to compute. It makes it clear where the "hot" and "cold" part of Suzuki's season were.</li>
 453       <li>If you set the averaging period to something large, like 200, you'll see the team's and player's batting average through that game. The final number is the overall batting average for the season.</li>
 454       <li>Where the error bars do not overlap, we can say with 95% confidence that the series differ. There is a better than 95% chance that Ichiro was a better hitter than his team as a whole in 2004, the year he won the batting title.</li>
 455     </ul>
 456
 457     <h2 id="stock">One last demo</h2>
 458
 459     <p>This chart shows monthly closes of the Dow Jones Industrial Average, both in nominal and real (i.e. adjusted for inflation) dollars. The shaded areas show its monthly high and low. CPI values with a base from 1982-84 are used to adjust for inflation.</p>
 460
 461     <div id="dow_chart" style="width:900px; height:350px;"></div>
 462     <p><b>Display: </b>
 463     <input type=checkbox id=0 onClick="stockchange(this)" checked>
 464     <label for="0"> Nominal</label>
 465     <input type=checkbox id=1 onClick="stockchange(this)" checked>
 466     <label for="1"> Real</label>
 467     <input type=checkbox id=ann onClick="annotationschange(this)" checked>
 468     <label for="ann"> Annotations</label>
 469     </p>
 470
 471     <script type="text/javascript">
 472       var stock_annotations = [
 473         {
 474           series: "Real",
 475           x: "1929-08-15",
 476           shortText: "A",
 477           text: "1929 Stock Market Peak"
 478         },
 479         {
 480           series: "Nominal",
 481           x: "1987-08-15",
 482           shortText: "B",
 483           text: "1987 Crash"
 484         },
 485         {
 486           series: "Nominal",
 487           x: "1999-12-15",
 488           shortText: "C",
 489           text: "1999 (.com) Peak"
 490         },
 491         {
 492           series: "Nominal",
 493           x: "2007-10-15",
 494           shortText: "D",
 495           text: "All-Time Market Peak"
 496         }
 497       ];
 498
 499     // From http://www.econstats.com/eqty/eq_d_mi_3.csv
 500       stockchart = new Dygraph(
 501         document.getElementById('dow_chart'),
 502         "dow.txt",
 503         {
 504           showRoller: true,
 505           customBars: true,
 506           labelsKMB: true,
 507           drawCallback: function(g, is_initial) {
 508             if (!is_initial) return;
 509             g.setAnnotations( stock_annotations );
 510           }
 511         }
 512       );
 513
 514       function stockchange(el) {
 515         stockchart.setVisibility(el.id, el.checked);
 516       }
 517
 518       function annotationschange(el) {
 519         if (el.checked) {
 520           stockchart.setAnnotations(stock_annotations);
 521         } else {
 522           stockchart.setAnnotations([]);
 523         }
 524       }
 525     </script>
 526 <!--
 527
 528 Here is a script to regenerate the Dow Jones plot:
 529
 530 # Get unadjusted DJIA data in a nice format:
 531 curl -O http://www.econstats.com/eqty/eq_d_mi_3.csv
 532 sed '1,17d' eq_d_mi_3.csv | cut -d, -f1,6 | perl -pe 's/(\d{4}-\d\d)-\d\d/$1/g' | perl -pe 's/, */\t/' | grep -v 'na' | perl -ne 'chomp; ($m,$v) = split/\t/; $close{$m} = $v; if ($low{$m} == 0 || $v < $low{$m}) { $low{$m}=$v } if ($v > $high{$m}) { $high{$m} = $v } END { for $x(sort keys %close) { print "$x\t$low{$x}\t$close{$x}\t$high{$x}\n" } } ' > monthly-djia.tsv
 533
 534 # Fetch and format the CPI data:
 535 curl 'http://data.bls.gov/PDQ/servlet/SurveyOutputServlet?series_id=CUUR0000SA0&years_option=all_years&periods_option=all_periods&output_type=column&output_format=text&delimiter=comma' > cpi-u.txt
 536 sed '1,/Series Id,Year,/d' cpi-u.txt | sed '/^$/,$d' | cut -d, -f2,3,4 | perl -ne 'print if /,M(0[0-9]|1[012]),/' | perl -pe 's/(\d{4}),M(\d{2}),/$1-$2\t/g' > cpi-u.tsv
 537
 538 # Merge:
 539 join -t'     ' cpi-u.tsv monthly-djia.tsv > annotated-djia.tsv
 540 perl -ne 'BEGIN{print "Month,Nominal,Real\n"} chomp; ($m,$cpi,$low,$close,$high) = split /\t/; $cpi /= 100.0; print "$m-15,$low;$close;$high,",($low/$cpi),";",($close/$cpi),";",($high/$cpi),"\n"' annotated-djia.tsv > dow.txt
 541
 542 -->
 543
 544     <h2 id="options">Other Options</h2>
 545
 546     <p>In addition to the options mentioned above (<code>showRoller</code>, <code>rollPeriod</code>, <code>errorBars</code>, <code>valueRange</code>), there are <i>many</i> others.</p>
 547
 548     <p>For a full list, see the <a href="options.html">Dygraphs Options Reference</a> page.</p>
 549
 550     <h2>Common Gotchas</h2>
 551
 552     <p>Here are a few problems that I've frequently run into while using the dygraphs library.</p>
 553
 554     <ul>
 555       <li>If your chart doesn't display, be sure to check your browser's JavaScript error console. dygraphs makes every attempt to log errors and warnings, and these can often guide you in the right direction.</li>
 556       <li>Make sure your CSV files are readable! If your graph isn't showing up, the XMLHttpRequest for the CSV file may be failing. You can determine whether this is the case using tools like <a href="http://www.getfirebug.com/">Firebug</a>.</li>
 557       <li>Make sure your CSV files are in the correct format. They must be of the form <code>YYYYMMDD, series1, series2, </code>&hellip; . And if you set the <code>errorBars</code> property, make sure you alternate data series and standard deviations.</li>
 558       <li>dygraphs are not happy when placed inside a <code>&lt;center&gt;</code> tag. This applies to the CSS <code>text-align</code> property as well. If you want to center a Dygraph, put it inside a table with <code>align = center</code> set.</li>
 559       <li>Don't set the <code>dateWindow</code> property to a date. It expects milliseconds since epoch, which can be obtained from a JavaScript Date object's valueOf method.</li>
 560       <li>Make sure you don't have any trailing commas in your call to the Dygraph constructor or in the options parameter. Firefox, Chrome and Safari ignore these but they can cause a graph to not display in Internet Explorer.</li>
 561     </ul>
 562
 563     <h2 id="gwt">GWT Compatibility</h2>
 564     <p>There is currently no GWT wrapper around Dygraphs, however there is a class that can be used to easily load Dygraphs into the browser.  To use it, include the generated dygraph-gwt.jar file in your classpath and add the following line to your GWT module:</p>
 565
 566 <pre>
 567 &lt;inherits name=&quot;org.danvk.dygraphs&quot;/&gt;
 568 </pre>
 569
 570     <p>Call org.danvk.Dygraphs.install() when your application starts to install the JavaScript code into the browser.  You can use <a href="http://code.google.com/webtoolkit/doc/latest/DevGuideCodingBasicsJSNI.html">JSNI</a> to call Dygraphs from your GWT code, as in the example below.  The example uses the <a href="http://code.google.com/p/gwt-google-apis/wiki/VisualizationGettingStarted">Visualization API for GWT</a> and the <a href="#gviz">Dygraphs GViz API.</a></p>
 571
 572 <pre>
 573   public static native JavaScriptObject drawDygraph(Element element, DataTable dataTable, double minY, double maxY) /*-{
 574     var chart = new $wnd.Dygraph.GVizChart(element);
 575     chart.draw(dataTable,
 576       {
 577         valueRange: [minY, maxY]
 578       });
 579     return chart;
 580   }-*/;
 581 </pre>
 582
 583     <h2 id="policy">Data Policy</h2>
 584     <p>dygraphs is purely client-side JavaScript. It does not send your data to any servers &ndash; the data is processed entirely in the client's browser.</p>
 585
 586     <p style="font-size:0.8em">Created May 9, 2008 by <a href=mailto:danvdk@gmail.com>Dan Vanderkam</a></p>
 587   </div>
 588
 589
 590   <!-- Google Analytics -->
 591   <script src="http://www.google-analytics.com/urchin.js" type="text/javascript"></script>
 592   <script type="text/javascript">_uacct = "UA-769809-1";urchinTracker();</script>
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 594 </html>