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  54 <ul>
  55 <li><b>Documentation</b>
  56   <ul>
  57   <li><a href="#demo">Demo</a>
  58   <li><a href="#usage">Usage</a>
  59   <li><a href="#ie">IE Compatibility</a>
  60   <li><a href="#baseball">Baseball chart</a>
  61   <li><a href="#stock">Stock chart</a>
  62   <li><a href="#options">Options Reference</a>
  63   <li><a href="#policy">Data Policy</a>
  64   </ul>
  65
  66 <li><b>Project</b>
  67   <ul>
  68   <li><a href="http://github.com/danvk/dygraphs">Source</a>
  69   <li><a href="http://code.google.com/p/dygraphs/issues/">Issues</a>
  70   <li><a href="http://code.google.com/p/dygraphs/issues/entry">Report Bug</a>
  71   <li><a href="mailto:danvdk [at] gmail">Contact</a>
  72   </ul>
  73
  74
  75 <li><b>Gallery</b>
  76   <ul>
  77   <li><a href="tests/demo.html">Basic Demo</a>
  78   <li><a href="tests/gviz.html">GViz Demo</a>
  79   <li><a href="tests/plotter.html">Equation Plotter</a>
  80   <li><a href="tests/perf.html">Performance Test</a>
  81   <li><a href="tests/perf.html">Fractions</a>
  82
  83   <li><a href="tests/label-div.html">Labels in a DIV</a>
  84   <li><a href="tests/numeric-axis.html">Numeric Axis</a>
  85   <li><a href="tests/draw-points.html">Dotted Points</a>
  86
  87   <li><a href="tests/native-format.html">Native Format</a>
  88   <li><a href="tests/grid_dot.html">Crazy Styles</a>
  89   <li><a href="tests/spacing.html">Tick spacing</a>
  90   <li><a href="tests/callback.html">Callbacks</a>
  91   <li><a href="tests/crosshair.html">Crosshairs</a>
  92   <li><a href="tests/hourly.html">Hourly/Minutely data</a>
  93
  94   <li><a href="tests/isolated-points.html">Isolated Points</a>
  95   <li><a href="tests/missing-data.html">Missing Data</a>
  96
  97   <li><a href="tests/border.html">Bordered chart</a>
  98   <li><a href="tests/custom-bars.html">Custom Bars</a>
  99   <li><a href="tests/customLabel.html">Custom Label Styles</a>
 100   <li><a href="tests/dygraph.html">Minimal Example</a>
 101   <li><a href="tests/negative.html">Negative Numbers</a>
 102   <li><a href="tests/noise.html">Noisy Data</a>
 103   <li><a href="tests/two-series.html">Multiple Series</a>
 104   </ul>
 105 </ul>
 106 </div>
 107
 108 <div id="content">
 109 <p><span style="font-size:28pt;">dygraphs JavaScript Visualization Library</span><br/>
 110 <a href="http://github.com/danvk/dygraphs">http://github.com/danvk/dygraphs</a><br/>
 111 See <a href="tests/">gallery</a> and <a href="http://code.google.com/p/dygraphs/issues/">open issues</a></p>
 112
 113 <p>The dygraphs JavaScript library 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>
 114
 115 <a name="demo">
 116 <p>A demo is worth a thousand words:</p>
 117
 118 <p><font size=-1>(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.)</font></p>
 119 <div id="title" style="width:800px; text-align:center; font-weight: bold; font-size: 125%;">Temperatures in New York vs. San Francisco</div>
 120 <div id="demodiv" style="width:800px; height:320px;"></div>
 121 <script type="text/javascript">
 122   g = new Dygraph(
 123           document.getElementById("demodiv"),
 124           "ny-vs-sf.txt",
 125           {
 126             rollPeriod: 14,
 127             showRoller: true,
 128             customBars: true,
 129             yAxisLabelWidth: 30
 130           }
 131       );
 132 </script>
 133
 134 <p>Some things to notice:</p>
 135 <ul>
 136 <li>There's less seasonal temperature variation in SF than in NY.
 137 <li>The difference is about 15&deg; F for SF vs. 50&deg; F for NY.
 138 <li>The daily data (set rolling period to 1) is quite noisy and hides this conclusion.
 139 <li>Using a 14-day moving average makes it clearer. A 100-day rolling period averages out nearly all the specifics from the data.
 140 <li>There's a gap in the data for SF, when the weather station was down (zoom into October 2007 to see it).
 141 <li>The bands around each point indicate average highs and lows.
 142 <li>There is a <i>lot</i> 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.
 143 </ul>
 144
 145 <p>dygraphs allows the user to explore the data and discover these facts.</p>
 146
 147 <p>For more demos, browse the dygraph <a href="tests/">tests</a> directory.</p>
 148
 149 <h3>Features</h3>
 150 <p>Some of the features of dygraphs:</p>
 151 <ul>
 152   <li>Plots time series without using an external server or Flash</li>
 153   <li>Works in Internet Explorer (using excanvas)</li>
 154   <li>Lightweight (45kb) and responsive</li>
 155   <li>Displays values on mouseover (this makes it easily discoverable)</li>
 156   <li>Supports error bands around data series</li>
 157   <li>Interactive zoom</li>
 158   <li>Adjustable averaging period</li>
 159   <li>Can intelligently chart fractions</li>
 160   <li>Customizable click-through actions</li>
 161   <li>Compatible with the Google Visualization API</li>
 162   <li>Intelligent defaults make it easy to use</li>
 163 </ul>
 164
 165 <a name="usage"><h2>Usage</h2>
 166
 167 <p>To use dygraphs, include the <code>dygraph-combined.js</code> JavaScript file and instantiate a <code>Dygraph</code> object.</p>
 168
 169 <p>Here's a basic example to get things started:</p>
 170
 171 <table>
 172   <tr><th>HTML</th>
 173       <td rowspan=2><img src=arrow.gif /></td>
 174       <th>Output</th></tr>
 175 <tr>
 176 <td valign=top><pre>
 177 &lt;html&gt;
 178 &lt;head&gt;
 179 &lt;script type="text/javascript"
 180   src="dygraph-combined.js"&gt;&lt;/script&gt;
 181 &lt;/head&gt;
 182 &lt;body&gt;
 183 &lt;div id="graphdiv"&gt;&lt;/div&gt;
 184 &lt;script type="text/javascript"&gt;
 185   g = new Dygraph(
 186         // containing div
 187         document.getElementById("graphdiv"),
 188         // CSV or path to a CSV file.
 189         "Date,Temperature\n" +
 190         "2008-05-07,75\n" +
 191         "2008-05-08,70\n" +
 192         "2008-05-09,80\n"
 193       );
 194 &lt;/script&gt;
 195 &lt;/body&gt;
 196 &lt;/html&gt;
 197 </pre>
 198 </td><td valign=top>
 199   <div id="graphdiv"></div>
 200 </td></tr></table>
 201
 202 <script type="text/javascript">
 203   g1 = new Dygraph(
 204        document.getElementById("graphdiv"),  // containing div
 205        "Date,Temperature\n" +                // CSV or path to a CSV file.
 206        "2008-05-07,75\n" +
 207        "2008-05-08,70\n" +
 208        "2008-05-09,80\n"
 209      );
 210 </script>
 211
 212 <p>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 the its container to a reasonable default, calculates appropriate axis ranges and tick marks and draws the graph.</p>
 213
 214 <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&monthend=12&yearend=2007&req_city=NA&req_state=NA&req_statename=NA">Weather Underground</a>)</p>
 215
 216 <table>
 217   <tr><th>HTML</th>
 218       <td rowspan=2><img src=arrow.gif /></td>
 219       <th>Output</th></tr>
 220 <tr>
 221 <td valign=top><pre>
 222 &lt;html&gt;
 223 &lt;head&gt;
 224 &lt;script type="text/javascript"
 225   src="dygraph-combined.js"&gt;&lt;/script&gt;
 226 &lt;/head&gt;
 227 &lt;body&gt;
 228 &lt;div id="graphdiv"
 229   style="width:500px; height:300px;"&gt;&lt;/div&gt;
 230 &lt;script type="text/javascript"&gt;
 231   new Dygraph(
 232     document.getElementById("graphdiv"),
 233     "temperatures.csv",  // path to CSV file
 234     {}                   // options
 235   );
 236 &lt;/script&gt;
 237 &lt;/body&gt;
 238 &lt;/html&gt;
 239 </pre>
 240 </td><td valign=top>
 241   <div id="graphdiv2" style="width:500px; height:300px;"></div>
 242 </td></tr></table>
 243
 244 <script type="text/javascript">
 245   g2 = new Dygraph(
 246         document.getElementById("graphdiv2"),
 247         "temperatures.csv", {}
 248       );
 249 </script>
 250
 251 <p>Click <a href="temperatures.csv">here</a> to view the <code>temperatures.csv</code> file. There are a few things to note here:</p>
 252
 253 <ul>
 254   <li>The Dygraph sent off an XHR to get the temperatures.csv file.</li>
 255   <li>The labels were taken from the first line of <code>temperatures.csv</code>, which is <code>Date,High,Low</code>.</li>
 256   <li>The Dygraph automatically chose two different, easily-distinguishable colors for the two data series.</li>
 257   <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>
 258   <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>
 259   <li>The data is very spiky. A moving average would be easier to interpret.</li>
 260 </ul>
 261
 262 <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>
 263
 264 <table>
 265   <tr><th>HTML</th>
 266       <td rowspan=2><img src=arrow.gif /></td>
 267       <th>Output</th></tr>
 268 <tr>
 269 <td valign=top><pre>
 270 &lt;html&gt;
 271 &lt;head&gt;
 272 &lt;script type="text/javascript"
 273   src="dygraph-combined.js"&gt;&lt;/script&gt;
 274 &lt;/head&gt;
 275 &lt;body&gt;
 276 &lt;div id="graphdiv"
 277   style="width:500px; height:300px;"&gt;&lt;/div&gt;
 278 &lt;script type="text/javascript"&gt;
 279   g = new Dygraph(
 280         document.getElementById("graphdiv"),
 281         "temperatures.csv",
 282         { rollPeriod: 7,
 283           showRoller: true,
 284         }
 285       );
 286 &lt;/script&gt;
 287 &lt;/body&gt;
 288 &lt;/html&gt;
 289 </pre>
 290 </td><td valign=top>
 291   <div id="graphdiv3" style="width:500px; height:300px;"></div>
 292 </td></tr></table>
 293
 294 <script type="text/javascript">
 295   g3 = new Dygraph(
 296         document.getElementById("graphdiv3"),
 297         "temperatures.csv",
 298         { rollPeriod: 7,
 299           showRoller: true });
 300 </script>
 301
 302 <p>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>
 303
 304 <h2>Error Bars</h2>
 305 <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 +/-<i>n</i> 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. <i>&sigma;</i> = sqrt((<i>&sigma;_1</i>^2 + <i>&sigma;_2</i>^2 + ... + <i>&sigma;_n</i>^2)/<i>n</i>))</p>
 306
 307 <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 <a href="twonormals.csv">here</a>.</p>
 308
 309 <table>
 310   <tr><th>HTML</th>
 311       <td rowspan=2><img src=arrow.gif /></td>
 312       <th>Output</th></tr>
 313 <tr>
 314 <td valign=top><pre>
 315 &lt;html&gt;
 316 &lt;head&gt;
 317 &lt;script type="text/javascript"
 318   src="combined.js"&gt;&lt;/script&gt;
 319 &lt;/head&gt;
 320 &lt;body&gt;
 321 &lt;div id="graphdiv"
 322  style="width:600px; height:300px;"
 323  &gt;&lt;/div&gt;
 324 &lt;script type="text/javascript"&gt;
 325 $ = document.getElementById;
 326 g = new Dygraph(
 327   $("graphdiv"),
 328   "twonormals.csv",
 329   { rollPeriod: 7,
 330     showRoller: true,
 331     errorBars: true,
 332     valueRange: [50,125]
 333   }
 334 );
 335 &lt;/script&gt;
 336 &lt;/body&gt;
 337 &lt;/html&gt;
 338 </pre>
 339 </td><td valign=top>
 340   <div id="graphdiv4" style="width:600px; height:300px;"></div>
 341 </td></tr></table>
 342
 343 <script type="text/javascript">
 344 $ = document.getElementById;
 345 new Dygraph(
 346   document.getElementById("graphdiv4"),
 347   "twonormals.csv",
 348   { rollPeriod: 14,
 349     showRoller: true,
 350     errorBars: true,
 351     valueRange: [50, 125]
 352   }
 353 );
 354 </script>
 355
 356 <p>Things to note here:</p>
 357 <ul>
 358   <li>The <b>errorBars</b> option affects both the interpretation of the CSV file and the display of the graph. When <b>errorBars</b> is set to true, each line is interpreted as <i>YYYYMMDD</i>,<i>A</i>,<i>sigma_A</i>,<i>B</i>,<i>sigma_B</i>,...</li>
 359   <li>The first line of the CSV file doesn't mention the error columns. In this case, it's just "Date,Series1,Series2".</li>
 360   <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>
 361   <li>The error bars are partially transparent. This can be seen when they overlap one another.</li>
 362 </ul>
 363
 364 <a name="ie"><h2>Internet Explorer Compatibility</h2>
 365
 366 <p>The dygraphs library relies heavily on HTML's &lt;canvas&gt; tag, which
 367 Microsoft Internet Explorer does not support. Fortunately, some clever engineers
 368 created the <a href="http://code.google.com/p/explorercanvas/">excanvas</a>
 369 library, which imlements the &lt;canvas&gt; tag in IE using VML.</p>
 370
 371 <p>You can add IE support to any page using dygraphs by including the following
 372 in your page:</p>
 373
 374 <pre>
 375 &lt;head&gt;
 376 &lt;!--[if IE]&gt;&lt;script src="excanvas.js"&gt;&lt;/script&gt;&lt;![endif]--&gt;
 377 &lt;/head&gt;
 378 </pre>
 379
 380 <p>This works quite well in practice. Charts are responsive, even under VML
 381 emulation.</p>
 382
 383 <p>One common gotcha to look out for: make sure you don't have any trailing
 384 commas in parameter lists, e.g.</p>
 385
 386 <pre>new Dygraph(el, data, {
 387   showRoller:true,  // &lt;-- note trailing comma
 388 })</pre>
 389
 390 <p>Most browsers will ignore the trailing comma, but it will break under IE.</p>
 391
 392 <a name="baseball"><h2>Charting Fractions</h2>
 393 <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>
 394
 395 <ul>
 396 <li>The average of <code>a1/b1</code> and <code>a2/b2</code> is
 397 <code>(a1+a2)/(b1+b2)</code>, not <code>(a1/b1 + a2/b2)/2</code>.
 398 <li>The normal approximation is not always applicable and more sophisticated
 399 confidence intervals (e.g. the <a
 400 href="http://en.wikipedia.org/wiki/Binomial_proportion_confidence_interval">Wilson
 401 confidence interval</a>) must be employed to avoid ratios that exceed 100% or
 402 go below 0%.
 403 </ul>
 404
 405 <p>Fortunately, dygraphs handles both of these for you! Here's a chart and the command that generated it:</p>
 406
 407 <div style="width:750px; text-align:center; font-weight: bold; font-size: 125%;">Batting Average for Ichiro Suzuki vs. Mariners (2004)</div>
 408 <div id="baseballdiv" style="width:750px; height:300px;"></div>
 409 <script type="text/javascript">
 410 new Dygraph(document.getElementById("baseballdiv"),
 411             "suzuki-mariners.txt", {
 412               fractions: true,
 413               errorBars: true,
 414               showRoller: true,
 415               rollPeriod: 15
 416             });
 417 </script>
 418
 419 <p>Command:</p>
 420 <pre>
 421 new Dygraph(
 422   document.getElementById("baseballdiv"), "suzuki-mariners.txt",
 423   {
 424     fractions: true, errorBars: true,
 425     showRoller: true, rollPeriod: 15
 426   });
 427 </pre>
 428
 429 <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>
 430
 431 <p>A couple things to notice about this chart:</p>
 432 <ul>
 433 <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.
 434 <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.
 435 <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.
 436 <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.
 437 </ul>
 438
 439 <a name="stock"><h2>One last demo</h2>
 440
 441 <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>
 442
 443 <div id=dow_chart style="width:900px; height:350px;"></div>
 444 <script type="text/javascript">
 445   // From http://www.econstats.com/eqty/eq_d_mi_3.csv
 446   dow = new Dygraph(
 447     document.getElementById('dow_chart'),
 448     "dow.txt",
 449     {
 450       showRoller: true,
 451       customBars: true,
 452       labelsKMB: true });
 453 </script>
 454 <!--
 455
 456 Here is a script to regenerate the Dow Jones plot:
 457
 458 # Get unadjusted DJIA data in a nice format:
 459 curl -O http://www.econstats.com/eqty/eq_d_mi_3.csv
 460 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
 461
 462 # Fetch and format the CPI data:
 463 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
 464 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-$2\t/g' > cpi-u.tsv
 465
 466 # Merge:
 467 join -t'       ' cpi-u.tsv monthly-djia.tsv > annotated-djia.tsv
 468 perl -ne 'BEGIN{print "Month,Nominal,Real\n"} chomp; ($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
 469
 470 -->
 471
 472
 473 <a name="options">
 474 <h2>Other Options</h2>
 475 <p>These are the options that can be passed in through the optional third parameter of the Dygraph constructor. To see demonstrations of many of these options, browse the <a href="tests/">dygraphs tests</a> directory.</p>
 476
 477 <table class=thinborder width=900>
 478   <tr><th>Name</th><th>Sample Value</th><th>Description</th></tr>
 479   <tr>
 480     <td><b>includeZero</b></td>
 481     <td><code>true, false</code></td>
 482     <td>Usually, dygraphs will use the range of the data plus some padding to
 483     set the range of the y-axis. If this option is set, the y-axis will always
 484     include zero, typically as the lowest value. This can be used to avoid
 485     exaggerating the variance in the data.</td>
 486   </tr>
 487
 488   <tr>
 489     <td><b>rollPeriod</b></td>
 490     <td><code>7</code></td>
 491     <td>Number of days over which to average data. Discussed extensively above.</td>
 492   </tr>
 493
 494   <tr>
 495     <td><b>showRoller</b></td>
 496     <td><code>true</code></td>
 497     <td>Should the rolling average period text box be shown? Default is false.</td>
 498   </tr>
 499
 500   <tr>
 501     <td><b>colors</b></td>
 502     <td><code>['red',&nbsp;'#00FF00']</code></td>
 503     <td>List of colors for the data series. These can be of the form "#AABBCC"
 504       or "rgb(255,100,200)" or "yellow", etc. If not specified, equally-spaced
 505       points around a color wheel are used.</td>
 506   </tr>
 507
 508   <tr>
 509     <td><b>colorSaturation</b></td>
 510     <td><code>1.0</code></td>
 511     <td>If <b>colors</b> is not specified, saturation of the
 512       automatically-generated data series colors. (0.0-1.0, default:
 513       1.0)</td>
 514   </tr>
 515
 516   <tr>
 517     <td><b>colorValue</b></td>
 518     <td><code>0.5</code></td>
 519     <td>If colors is not specified, value of the data series colors, as in
 520       hue/saturation/value. (0.0-1.0, default 0.5)</td>
 521   </tr>
 522
 523   <tr>
 524     <td><b>clickCallback</b></td>
 525     <td><code>function(e,date){ alert(date); }</code></td>
 526     <td>A function to call when a data point is clicked. The function should take
 527       two arguments, the event object for the click and the date that was
 528       clicked. (default null)</td>
 529   </tr>
 530
 531   <tr>
 532     <td><b>zoomCallback</b></td>
 533     <td><code>function(minDate,maxDate) {}</code></td>
 534     <td>A function to call when the zoom window is changed (either by zooming
 535     in or out). minDate and maxDate are millis since epoch.</td>
 536   </tr>
 537
 538   <tr>
 539     <td><b>strokeWidth</b></td>
 540     <td><code>2.0</code></td>
 541     <td>Width of the data lines. This can be used to increase the contrast or
 542       some graphs. (default 1.0)</td>
 543   </tr>
 544
 545   <tr>
 546     <td><b>dateWindow</b></td>
 547     <td><code>[Date.parse('2006-01-01'),<br/>
 548         (new&nbsp;Date()).valueOf()]</code></td>
 549     <td>Initially zoom in on a section of the graph. Is of the form [earliest,
 550       latest], where earliest/latest are millis since epoch.  By default, the
 551       full range of the input is shown.</td>
 552   </tr>
 553
 554   <tr>
 555     <td><b>valueRange</b></td>
 556     <td><code>[10, 110]</code></td>
 557     <td>Explicitly set the vertical range of the graph to [low, high]. By
 558       default, some clever heuristics are used (see above).</td>
 559   </tr>
 560
 561   <tr>
 562     <td><b>labelsSeparateLines</b></td>
 563     <td><code>true</code></td>
 564     <td>Put &lt;br/&gt; between lines in the label string. Often used in
 565       conjunction with <b>labelsDiv</b>. (default false)</td>
 566   </tr>
 567
 568   <tr>
 569     <td><b>labelsDiv</b></td>
 570     <td><code>document.getElementById('foo')</code></td>
 571     <td>Show data labels in an external div, rather than on the graph. (default
 572       null)</td>
 573   </tr>
 574
 575   <tr>
 576     <td><b>labelsKMB</b></td>
 577     <td><code>true</code></td>
 578     <td>Show K/M/B for thousands/millions/billions on y-axis (default
 579       false).</td>
 580   </tr>
 581
 582   <tr>
 583     <td><b>labelsDivWidth</b></td>
 584     <td>250</td>
 585     <td>Width (in pixels) of the div which shows information on the
 586     currently-highlighted points.</td>
 587   </tr>
 588
 589   <tr>
 590     <td><b>labelsDivStyles</b></td>
 591     <td>{}</td>
 592     <td>Additional styles to apply to the currently-highlighted points div. For
 593     example, { 'font-weigth': 'bold' } will make the labels bold.</td>
 594   </tr>
 595
 596   <tr>
 597     <td><b>highlightCircleSize</b></td>
 598     <td><code>3</code></td>
 599     <td>Size (in pixels) of the dot drawn over highlighted points (default 3).</td>
 600   </tr>
 601
 602   <tr>
 603     <td><b>drawPoints</b></td>
 604     <td><code>false</code></td>
 605     <td>Draw a small dot at each point, in addition to a line going through
 606     the point. This makes the individual data points easier to see, but can
 607     increase visual clutter in the chart. Default: false</td>
 608   </tr>
 609
 610   <tr>
 611     <td><b>pointSize</b></td>
 612     <td><code>1.0</code></td>
 613     <td>The size of the dot to draw on each point in pixels (see
 614     drawPoints). A dot is always drawn when a point is "isolated", i.e.
 615     there is a missing point on either side of it. This also controls the
 616     size of those dots.</td>
 617   </tr>
 618
 619   <tr>
 620     <td><b>pixelsPerXLabel</b>, <b>pixelsPerYLabel</b></td>
 621     <td>50</td>
 622     <td>Number of pixels to require between each x- and y-label. Larger values
 623     will yield a sparser axis with fewer ticks. Defaults: 60 (x-axis), 30
 624     (y-axis).</td>
 625   </tr>
 626
 627   <tr>
 628     <td><b>xAxisLabelWidth</b>, <b>yAxisLabelWidth</b></td>
 629     <td>50</td>
 630     <td>Width (in pixels) of the x- and y-axis labels.</td>
 631   </tr>
 632
 633   <tr>
 634     <td><b>axisLabelFontSize</b></td>
 635     <td>14</td>
 636     <td>Size of the font (in pixels) to use in the axis labels, both x- and
 637     y-axis.</td>
 638   </tr>
 639
 640   <tr>
 641     <td><b>rightGap</b></td>
 642     <td>5</td>
 643     <td>Number of pixels to leave blank at the right edge of the Dygraph. This
 644     makes it easier to highlight the right-most data point.</td>
 645   </tr>
 646
 647   <tr>
 648     <td><b>errorBars</b></td>
 649     <td><code>false</code></td>
 650     <td>Does the data contain standard deviations? Setting this to true alters
 651       the input format (see above). (default false)</td>
 652   </tr>
 653
 654   <tr>
 655     <td><b>sigma</b></td>
 656     <td>2</td>
 657     <td>When errorBars is set, shade this many standard deviations above/below
 658     each point.</td>
 659   </tr>
 660
 661   <tr>
 662     <td><b>fractions</b></td>
 663     <td>false</td>
 664     <td>When set, attempt to parse each cell in the CSV file as "a/b", where a
 665     and b are integers. The ratio will be plotted. This allows computation of
 666     Wilson confidence intervals (see below).</td>
 667   </tr>
 668
 669   <tr>
 670     <td><b>wilsonInterval</b></td>
 671     <td>true</td>
 672     <td>Use in conjunction with the "fractions" option. Instead of plotting +/-
 673     N standard deviations, dygraphs will compute a Wilson confidence interval
 674     and plot that. This has more reasonable behavior for ratios close to 0 or
 675     1.</td>
 676   </tr>
 677
 678   <tr>
 679     <td><b>customBars</b></td>
 680     <td>false</td>
 681     <td>When set, parse each CSV cell as "low;middle;high". Error bars will be
 682     drawn for each point between low and high, with the series itself going
 683     through middle.</td>
 684   </tr>
 685 </table>
 686
 687 <h2>Common Gotchas</h2>
 688 <p>Here are a few problems that I've frequently run into while using the
 689 dygraphs library.</p>
 690
 691 <ul>
 692   <li>Make sure your CSV files are readable! If your graph isn't showing up,
 693   the XMLHttpRequest for the CSV file may be failing. You can determine whether
 694   this is the case using tools like <a
 695     href="http://www.getfirebug.com/">Firebug</a>.</li>
 696
 697   <li>Make sure your CSV files are in the correct format. They must be of the
 698   form <code>YYYYMMDD,series1,series2,...</code>. And if you set the
 699   <code>errorBars</code> property, make sure you alternate data series and
 700   standard deviations.</li>
 701
 702   <li>dygraphs are not happy when placed inside a <code>&lt;center&gt;</code>
 703   tag. This applies to the CSS <code>text-align</code> property as well. If you
 704   want to center a Dygraph, put it inside a table with "align=center"
 705   set.</li>
 706
 707   <li>Don't set the <code>dateWindow</code> property to a date. It expects
 708   milliseconds since epoch, which can be obtained from a JavaScript Date
 709   object's valueOf method.</li>
 710
 711   <li>Make sure you don't have any trailing commas in your call to the Dygraph
 712   constructor or in the options parameter. Firefox, Chrome and Safari ignore
 713   these but they can cause a graph to not display in Internet Explorer.</li>
 714 </ul>
 715
 716 <a name="policy">
 717 <h2>Data Policy</h2>
 718 <p>dygraphs is purely client-side JavaScript. It does not send your data to any
 719 servers -- the data is processed entirely in the client's browser.</p>
 720
 721 <p><font size=-1>Created May 9, 2008 by <a href=mailto:danvdk@gmail.com>Dan Vanderkam</a></font></p>
 722
 723 </div>
 724
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