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