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  26       <h2>Documentation</h2>
  27       <ul>
  28         <li><a href="#demo">Demo</a></li>
  29         <li><a href="#usage">Usage</a></li>
  30         <li><a href="#ie">IE Compatibility</a></li>
  31         <li><a href="#gviz">GViz Data</a></li>
  32         <li><a href="#baseball">Baseball chart</a></li>
  33         <li><a href="#stock">Stock chart</a></li>
  34         <li><a href="#options">Options Reference</a></li>
  35         <li><a href="#gwt">GWT Compatibility</a></li>
  36         <li><a href="#policy">Data Policy</a></li>
  37       </ul>
  38
  39       <h2>Features</h2>
  40       <ul>
  41         <li><a href="data.html">Data Formats</a></li>
  42         <li><a href="annotations.html">Annotations</a></li>
  43       </ul>
  44
  45       <h2>Project</h2>
  46       <ul>
  47         <li><a href="http://github.com/danvk/dygraphs">Source</a></li>
  48         <li><a href="http://code.google.com/p/dygraphs/issues/">Issues</a></li>
  49         <li><a href="http://code.google.com/p/dygraphs/issues/entry">Report Bug</a></li>
  50         <li><a href="changes.html">Contribute a change</a></li>
  51         <li><a href="mailto:dygraphs-users [at] googlegroups.com">Contact</a></li>
  52       </ul>
  53
  54       <h2>Gallery</h2>
  55       <ul>
  56         <li><a href="tests/">(browse demos)</a></li>
  57         <li><a href="tests/demo.html">Basic Demo</a></li>
  58         <li><a href="tests/gviz.html">GViz Demo</a></li>
  59         <li><a href="tests/plotter.html">Equation Plotter</a></li>
  60         <li><a href="tests/perf.html">Performance Test</a></li>
  61         <li><a href="tests/annotation.html">Annotations</a></li>
  62         <li><a href="tests/annotation-gviz.html">Annotations (GViz)</a></li>
  63         <li><a href="tests/fillGraph.html">Filled Chart</a></li>
  64         <li><a href="tests/perf.html">Fractions</a></li>
  65         <li><a href="tests/visibility.html">Visibility</a></li>
  66         <li><a href="tests/label-div.html">Labels in a DIV</a></li>
  67         <li><a href="tests/numeric-axis.html">Numeric Axis</a></li>
  68         <li><a href="tests/draw-points.html">Dotted Points</a></li>
  69         <li><a href="tests/native-format.html">Native Format</a></li>
  70         <li><a href="tests/grid_dot.html">Crazy Styles</a></li>
  71         <li><a href="tests/spacing.html">Tick spacing</a></li>
  72         <li><a href="tests/callback.html">Callbacks</a></li>
  73         <li><a href="tests/crosshair.html">Crosshairs</a></li>
  74         <li><a href="tests/hourly.html">Hourly/Minutely data</a></li>
  75         <li><a href="tests/isolated-points.html">Isolated Points</a></li>
  76         <li><a href="tests/missing-data.html">Missing Data</a></li>
  77         <li><a href="tests/border.html">Bordered chart</a></li>
  78         <li><a href="tests/custom-bars.html">Custom Bars</a></li>
  79         <li><a href="tests/customLabel.html">Custom Label Styles</a></li>
  80         <li><a href="tests/dygraph.html">Minimal Example</a></li>
  81         <li><a href="tests/negative.html">Negative Numbers</a></li>
  82         <li><a href="tests/noise.html">Noisy Data</a></li>
  83         <li><a href="tests/two-series.html">Multiple Series</a></li>
  84         <li><a href="tests/highlighted-region.html">Custom Underlay / background</a></li>
  85         <li><a href="tests/zoom.html">Tests for zoom operations</a></li>
  86         <li><a href="tests/logscale.html">Log scale tests</a></li>
  87       </ul>
  88     </div>
  89
  90     <div id="content">
  91       <h1>dygraphs JavaScript Visualization Library</h1>
  92
  93       <p><a href="http://github.com/danvk/dygraphs">http://github.com/danvk/dygraphs</a></p>
  94       <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>
  95
  96       <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>
  97
  98       <h3 id="demo">A demo is worth a thousand words:</h3>
  99
 100       <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>
 101
 102       <div id="demodiv" style="width:800px; height:320px;"></div>
 103       <script type="text/javascript">
 104         g = new Dygraph(
 105           document.getElementById("demodiv"),
 106           "ny-vs-sf.txt",
 107           {
 108             rollPeriod: 14,
 109             showRoller: true,
 110             customBars: true,
 111             title: 'Daily Temperatures in New York vs. San Francisco',
 112             ylabel: 'Temperature (F)',
 113             titleHeight: 24
 114           }
 115         );
 116       </script>
 117
 118       <h4>Some things to notice:</h4>
 119       <ul>
 120         <li>There's less seasonal temperature variation in SF than in NY.</li>
 121         <li>The difference is about 15&deg; F for SF vs. 50&deg; F for NY.</li>
 122         <li>The daily data (set rolling period to 1) is quite noisy and hides this conclusion.</li>
 123         <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>
 124         <li>There's a gap in the data for SF, when the weather station was down (zoom into October 2007 to see it).</li>
 125         <li>The bands around each point indicate average highs and lows.</li>
 126         <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>
 127       </ul>
 128
 129       <p>dygraphs allows the user to explore the data and discover these facts.</p>
 130
 131       <p>For more demos, browse the dygraph <a href="tests/">tests</a> directory.</p>
 132
 133       <h3>Features</h3>
 134       <p>Some of the features of dygraphs:</p>
 135       <ul>
 136         <li>Plots time series without using an external server or Flash</li>
 137         <li>Works in Internet Explorer (using excanvas)</li>
 138         <li>Lightweight (69kb) and responsive</li>
 139         <li>Displays values on mouseover, making interaction easily discoverable</li>
 140         <li>Supports error bands around data series</li>
 141         <li>Interactive zoom</li>
 142         <li>Displays Annotations on the chart</li>
 143         <li>Adjustable averaging period</li>
 144         <li>Can intelligently chart fractions</li>
 145         <li>Customizable click-through actions</li>
 146         <li>Compatible with the Google Visualization API</li>
 147         <li>Intelligent defaults make it easy to use</li>
 148       </ul>
 149
 150       <h2 id="usage">Usage</h2>
 151
 152       <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>
 153
 154       <p>Here's a basic example to get things started:</p>
 155
 156       <div class="example" style="clear:both;">
 157         <div class="codeblock" style="float:left;width:400px;">
 158           <h3 style="text-align:center">HTML</h3>
 159           <code>
 160   <pre>
 161 &lt;html&gt;
 162 &lt;head&gt;
 163 &lt;script type=&quot;text/javascript&quot;
 164   src=&quot;dygraph-combined.js&quot;&gt;&lt;/script&gt;
 165 &lt;/head&gt;
 166 &lt;body&gt;
 167 &lt;div id=&quot;graphdiv&quot;&gt;&lt;/div&gt;
 168 &lt;script type=&quot;text/javascript&quot;&gt;
 169   g = new Dygraph(
 170
 171     // containing div
 172     document.getElementById(&quot;graphdiv&quot;),
 173
 174     // CSV or path to a CSV file.
 175     &quot;Date,Temperature\n&quot; +
 176     &quot;2008-05-07,75\n&quot; +
 177     &quot;2008-05-08,70\n&quot; +
 178     &quot;2008-05-09,80\n&quot;
 179
 180   );
 181 &lt;/script&gt;
 182 &lt;/body&gt;
 183 &lt;/html&gt;
 184 </pre>
 185           </code>
 186         </div>
 187         <div class="codeoutput" style="float:left;">
 188           <h3 style="text-align:center">OUTPUT</h3>
 189           <div id="graphdiv"></div>
 190           <script type="text/javascript">
 191             g = new Dygraph(
 192
 193               // containing div
 194               document.getElementById("graphdiv"),
 195
 196               // CSV or path to a CSV file.
 197               "Date,Temperature\n" +
 198               "2008-05-07,75\n" +
 199               "2008-05-08,70\n" +
 200               "2008-05-09,80\n"
 201             );
 202           </script>
 203         </div>
 204       </div>
 205
 206       <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>
 207
 208       <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>
 209
 210       <div class="example" style="clear:both;">
 211         <div class="codeblock" style="float:left;width:400px;">
 212           <h3 style="text-align:center">HTML</h3>
 213           <code>
 214 <pre>
 215 &lt;html&gt;
 216 &lt;head&gt;
 217 &lt;script type=&quot;text/javascript&quot;
 218   src=&quot;dygraph-combined.js&quot;&gt;&lt;/script&gt;
 219 &lt;/head&gt;
 220 &lt;body&gt;
 221 &lt;div id=&quot;graphdiv2&quot;
 222   style=&quot;width:500px; height:300px;&quot;&gt;&lt;/div&gt;
 223 &lt;script type=&quot;text/javascript&quot;&gt;
 224   g2 = new Dygraph(
 225     document.getElementById(&quot;graphdiv2&quot;),
 226     &quot;temperatures.csv&quot;, // path to CSV file
 227     {}          // options
 228   );
 229 &lt;/script&gt;
 230 &lt;/body&gt;
 231 &lt;/html&gt;
 232 </pre>
 233           </code>
 234         </div>
 235         <div class="codeoutput" style="float:left;">
 236           <h3 style="text-align:center">OUTPUT</h3>
 237           <div id="graphdiv2" style="width:500px; height:300px;"></div>
 238           <script type="text/javascript">
 239             g2 = new Dygraph(
 240               document.getElementById("graphdiv2"),
 241               "temperatures.csv",
 242               {}
 243             );
 244           </script>
 245         </div>
 246       </div>
 247
 248       <p style="clear:both;">The file used is <code><a href="temperatures.csv">temperatures.csv</a></code>.</p>
 249
 250       <p>There are a few things to note here:</p>
 251
 252       <ul>
 253         <li>The Dygraph sent off an XHR to get the temperatures.csv file.</li>
 254         <li>The labels were taken from the first line of <code>temperatures.csv</code>, which is <code>Date,High,Low</code>.</li>
 255         <li>The Dygraph automatically chose two different, easily-distinguishable colors for the two data series.</li>
 256         <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>
 257         <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>
 258         <li>The data is very spiky. A moving average would be easier to interpret.</li>
 259       </ul>
 260
 261       <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>
 262
 263       <div class="example" style="clear:both;">
 264         <div class="codeblock" style="float:left;width:400px;">
 265           <h3 style="text-align:center">HTML</h3>
 266           <code>
 267 <pre>
 268 &lt;html&gt;
 269 &lt;head&gt;
 270 &lt;script type=&quot;text/javascript&quot;
 271   src=&quot;dygraph-combined.js&quot;&gt;&lt;/script&gt;
 272 &lt;/head&gt;
 273 &lt;body&gt;
 274 &lt;div id=&quot;graphdiv3&quot;
 275   style=&quot;width:500px; height:300px;&quot;&gt;&lt;/div&gt;
 276 &lt;script type=&quot;text/javascript&quot;&gt;
 277   g3 = new Dygraph(
 278     document.getElementById(&quot;graphdiv3&quot;),
 279     &quot;temperatures.csv&quot;,
 280     {
 281       rollPeriod: 7,
 282       showRoller: true
 283     }
 284   );
 285 &lt;/script&gt;
 286 &lt;/body&gt;
 287 &lt;/html&gt;
 288 </pre>
 289           </code>
 290         </div>
 291         <div class="codeoutput" style="float:left;">
 292           <h3 style="text-align:center">OUTPUT</h3>
 293           <div id="graphdiv3" style="width:500px; height:300px;"></div>
 294           <script type="text/javascript">
 295             g3 = new Dygraph(
 296               document.getElementById("graphdiv3"),
 297               "temperatures.csv",
 298               {
 299                 rollPeriod: 7,
 300                 showRoller: true
 301               }
 302             );
 303           </script>
 304         </div>
 305       </div>
 306
 307       <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>
 308
 309       <h2>Error Bars</h2>
 310
 311       <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>
 312
 313       <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>
 314
 315       <div class="example" style="clear:both;">
 316         <div class="codeblock" style="float:left;width:400px;">
 317           <h3 style="text-align:center">HTML</h3>
 318           <code>
 319 <pre>
 320 &lt;html&gt;
 321 &lt;head&gt;
 322 &lt;script type=&quot;text/javascript&quot;
 323   src=&quot;combined.js&quot;&gt;&lt;/script&gt;
 324 &lt;/head&gt;
 325 &lt;body&gt;
 326 &lt;div id=&quot;graphdiv4&quot;
 327   style=&quot;width:600px; height:300px;&quot;&gt;&lt;/div&gt;
 328 &lt;script type=&quot;text/javascript&quot;&gt;
 329   g4 = new Dygraph(
 330     document.getElementById(&quot;graphdiv4&quot;),
 331     &quot;twonormals.csv&quot;,
 332     {
 333       rollPeriod: 7,
 334       showRoller: true,
 335       errorBars: true,
 336       valueRange: [50,125]
 337     }
 338   );
 339 &lt;/script&gt;
 340 &lt;/body&gt;
 341 &lt;/html&gt;
 342 </pre>
 343           </code>
 344         </div>
 345         <div class="codeoutput" style="float:left;">
 346           <h3 style="text-align:center">OUTPUT</h3>
 347           <div id="graphdiv4" style="width:600px; height:300px;"></div>
 348           <script type="text/javascript">
 349             g4 = new Dygraph(
 350               document.getElementById("graphdiv4"),
 351               "twonormals.csv",
 352               {
 353                 rollPeriod: 7,
 354                 showRoller: true,
 355                 errorBars: true,
 356                 valueRange: [50,125]
 357               }
 358             );
 359           </script>
 360         </div>
 361       </div>
 362
 363       <p style="clear:both;">Things to note here:</p>
 364
 365       <ul>
 366         <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>
 367         <li>The first line of the CSV file doesn't mention the error columns. In this case, it's just "Date,Series1,Series2".</li>
 368         <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>
 369         <li>The error bars are partially transparent. This can be seen when they overlap one another.</li>
 370       </ul>
 371
 372       <h2 id="ie">Internet Explorer Compatibility</h2>
 373
 374       <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>
 375
 376 <pre>
 377 &lt;!DOCTYPE html&gt;
 378 </pre>
 379
 380       <p>When IE9 is in HTML5 mode, dygraphs works just like in other modern browsers.</p>
 381
 382       <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 the following snippet:</p>
 383
 384 <pre>
 385 &lt;!DOCTYPE html&gt;
 386 &lt;html&gt;
 387   &lt;head&gt;
 388     &lt;meta http-equiv="X-UA-Compatible" content="IE=EmulateIE7; IE=EmulateIE9"&gt;
 389     &lt;!--[if IE]&gt;&lt;script src="path/to/excanvas.js"&gt;&lt;/script&gt;&lt;![endif]--&gt;
 390   &lt;/head&gt;
 391 </pre>
 392
 393 <p>(This is surprisingly tricky because the HTML5 doctype breaks excanvas in IE8. See <a href="https://groups.google.com/group/dygraphs-users/browse_thread/thread/c60709e04bc7fe5f#">this discussion</a> for details.)</p>
 394
 395     <p>While VML emulation sounds like it would be slow, it works well in practice for most charts.</p>
 396
 397     <p>One common gotcha to look out for: make sure you don't have any trailing commas in parameter lists, e.g.</p>
 398
 399 <pre>
 400 new Dygraph(el, data, {
 401   showRoller: true,  // note trailing comma
 402 })</pre>
 403
 404     <p>Most browsers will ignore the trailing comma, but it will break under IE.</p>
 405
 406     <h2 id="gviz">GViz Data</h2>
 407
 408     <p>The <a
 409       href="http://code.google.com/apis/visualization/documentation/index.html">Google
 410       Visualization API</a> provides a standard interface for describing data.
 411     Once you've specified your data using this API, you can plug in any
 412     GViz-compatible visualization. dygraphs is such a visualization. In
 413     particular, it can be used as a drop-in replacement for the
 414     AnnotatedTimeline visualization used on Google Finance and other sites. To
 415     see how this works, check out the <a href="tests/annotation-gviz.html">gviz
 416       annotation demo.</a></p>
 417
 418     <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>
 419
 420     <p>Here's an example of a published gviz gadget using dygraphs:</p>
 421
 422     <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>
 423
 424     <h2 id="baseball">Charting Fractions</h2>
 425
 426     <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>
 427
 428     <ul>
 429       <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>
 430       <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>
 431     </ul>
 432
 433     <p>Fortunately, dygraphs handles both of these for you! Here's a chart and the command that generated it:</p>
 434
 435     <div style="width:750px; text-align:center; font-weight: bold; font-size: 125%;">Batting Average for Ichiro Suzuki vs. Mariners (2004)</div>
 436     <div id="baseballdiv" style="width:750px; height:300px;"></div>
 437     <script type="text/javascript">
 438       new Dygraph(
 439         document.getElementById("baseballdiv"),
 440         "suzuki-mariners.txt",
 441         {
 442           fractions: true,
 443           errorBars: true,
 444           showRoller: true,
 445           rollPeriod: 15
 446         }
 447       );
 448     </script>
 449
 450     <p>Command:</p>
 451 <pre>
 452   new Dygraph(
 453     document.getElementById(&quot;baseballdiv&quot;),
 454     &quot;suzuki-mariners.txt&quot;,
 455     {
 456       fractions: true,
 457       errorBars: true,
 458       showRoller: true,
 459       rollPeriod: 15
 460     }
 461   );
 462 </pre>
 463
 464     <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>
 465
 466     <p>A couple things to notice about this chart:</p>
 467
 468     <ul>
 469       <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>
 470       <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>
 471       <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>
 472       <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>
 473     </ul>
 474
 475     <h2 id="stock">One last demo</h2>
 476
 477     <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>
 478
 479     <div id="dow_chart" style="width:900px; height:350px;"></div>
 480     <p><b>Display: </b>
 481     <input type=checkbox id=0 onClick="stockchange(this)" checked>
 482     <label for="0"> Nominal</label>
 483     <input type=checkbox id=1 onClick="stockchange(this)" checked>
 484     <label for="1"> Real</label>
 485     <input type=checkbox id=ann onClick="annotationschange(this)" checked>
 486     <label for="ann"> Annotations</label>
 487     </p>
 488
 489     <script type="text/javascript">
 490       var stock_annotations = [
 491         {
 492           series: "Real",
 493           x: "1929-08-15",
 494           shortText: "A",
 495           text: "1929 Stock Market Peak"
 496         },
 497         {
 498           series: "Nominal",
 499           x: "1987-08-15",
 500           shortText: "B",
 501           text: "1987 Crash"
 502         },
 503         {
 504           series: "Nominal",
 505           x: "1999-12-15",
 506           shortText: "C",
 507           text: "1999 (.com) Peak"
 508         },
 509         {
 510           series: "Nominal",
 511           x: "2007-10-15",
 512           shortText: "D",
 513           text: "All-Time Market Peak"
 514         }
 515       ];
 516
 517     // From http://www.econstats.com/eqty/eq_d_mi_3.csv
 518       stockchart = new Dygraph(
 519         document.getElementById('dow_chart'),
 520         "dow.txt",
 521         {
 522           showRoller: true,
 523           customBars: true,
 524           labelsKMB: true,
 525           drawCallback: function(g, is_initial) {
 526             if (!is_initial) return;
 527             g.setAnnotations( stock_annotations );
 528           }
 529         }
 530       );
 531
 532       function stockchange(el) {
 533         stockchart.setVisibility(el.id, el.checked);
 534       }
 535
 536       function annotationschange(el) {
 537         if (el.checked) {
 538           stockchart.setAnnotations(stock_annotations);
 539         } else {
 540           stockchart.setAnnotations([]);
 541         }
 542       }
 543     </script>
 544 <!--
 545
 546 Here is a script to regenerate the Dow Jones plot:
 547
 548 # Get unadjusted DJIA data in a nice format:
 549 curl -O http://www.econstats.com/eqty/eq_d_mi_3.csv
 550 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
 551
 552 # Fetch and format the CPI data:
 553 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
 554 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-$2\t/g' > cpi-u.tsv
 555
 556 # Merge:
 557 join -t'     ' cpi-u.tsv monthly-djia.tsv > annotated-djia.tsv
 558 perl -ne 'BEGIN{print "Month,Nominal,Real\n"} chomp; ($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
 559
 560 -->
 561
 562     <h2 id="options">Other Options</h2>
 563
 564     <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>
 565
 566     <p>For a full list, see the <a href="options.html">Dygraphs Options Reference</a> page.</p>
 567
 568     <h2>Common Gotchas</h2>
 569
 570     <p>Here are a few problems that I've frequently run into while using the dygraphs library.</p>
 571
 572     <ul>
 573       <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>
 574       <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>
 575       <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>
 576       <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>
 577       <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>
 578       <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>
 579     </ul>
 580
 581     <h2 id="gwt">GWT Compatibility</h2>
 582     <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>
 583
 584 <pre>
 585 &lt;inherits name=&quot;org.danvk.dygraphs&quot;/&gt;
 586 </pre>
 587
 588     <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>
 589
 590 <pre>
 591   public static native JavaScriptObject drawDygraph(Element element, DataTable dataTable, double minY, double maxY) /*-{
 592     var chart = new $wnd.Dygraph.GVizChart(element);
 593     chart.draw(dataTable,
 594       {
 595         valueRange: [minY, maxY]
 596       });
 597     return chart;
 598   }-*/;
 599 </pre>
 600
 601     <h2 id="policy">Data Policy</h2>
 602     <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>
 603
 604     <p style="font-size:0.8em">Created May 9, 2008 by <a href=mailto:danvdk@gmail.com>Dan Vanderkam</a></p>
 605   </div>
 606
 607 </body>
 608 </html>