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15c966e0 1<!DOCTYPE html>
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2<html>
3 <head>
fe57a69b 4 <title>dygraphs JavaScript Visualization Library</title>
078d1d29 5 <!--[if IE]>
15c966e0 6 <script type="text/javascript" src="excanvas.js"></script>
078d1d29 7 <![endif]-->
9f006dbf 8 <script type="text/javascript" src="dygraph-combined.js"></script>
15c966e0 9 <link rel="stylesheet" href="style.css">
078d1d29 10 </head>
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11 <body>
12 <div id="nav">
13 <h2>Documentation</h2>
14 <ul>
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15 <li><a href="#demo">Demo</a></li>
16 <li><a href="#usage">Usage</a></li>
17 <li><a href="#ie">IE Compatibility</a></li>
18 <li><a href="#gviz">GViz Data</a></li>
19 <li><a href="#baseball">Baseball chart</a></li>
20 <li><a href="#stock">Stock chart</a></li>
21 <li><a href="#options">Options Reference</a></li>
71ac4733 22 <li><a href="#gwt">GWT Compatibility</a></li>
68f9bed3 23 <li><a href="#policy">Data Policy</a></li>
15c966e0 24 </ul>
68f9bed3 25
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26 <h2>Features</h2>
27 <ul>
28 <li><a href="data.html">Data Formats</a></li>
29 <li><a href="annotations.html">Annotations</a></li>
30 </ul>
31
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32 <h2>Project</h2>
33 <ul>
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34 <li><a href="http://github.com/danvk/dygraphs">Source</a></li>
35 <li><a href="http://code.google.com/p/dygraphs/issues/">Issues</a></li>
36 <li><a href="http://code.google.com/p/dygraphs/issues/entry">Report Bug</a></li>
a843ade7 37 <li><a href="mailto:dygraphs-users [at] googlegroups.com">Contact</a></li>
15c966e0 38 </ul>
68f9bed3 39
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40 <h2>Gallery</h2>
41 <ul>
2b2a2f1c 42 <li><a href="tests/">(browse demos)</a></li>
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43 <li><a href="tests/demo.html">Basic Demo</a></li>
44 <li><a href="tests/gviz.html">GViz Demo</a></li>
45 <li><a href="tests/plotter.html">Equation Plotter</a></li>
46 <li><a href="tests/perf.html">Performance Test</a></li>
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47 <li><a href="tests/annotation.html">Annotations</a></li>
48 <li><a href="tests/annotation-gviz.html">Annotations (GViz)</a></li>
116bd142 49 <li><a href="tests/fillGraph.html">Filled Chart</a></li>
68f9bed3 50 <li><a href="tests/perf.html">Fractions</a></li>
bf5b5f4d 51 <li><a href="tests/visibility.html">Visibility</a></li>
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52 <li><a href="tests/label-div.html">Labels in a DIV</a></li>
53 <li><a href="tests/numeric-axis.html">Numeric Axis</a></li>
54 <li><a href="tests/draw-points.html">Dotted Points</a></li>
55 <li><a href="tests/native-format.html">Native Format</a></li>
56 <li><a href="tests/grid_dot.html">Crazy Styles</a></li>
57 <li><a href="tests/spacing.html">Tick spacing</a></li>
58 <li><a href="tests/callback.html">Callbacks</a></li>
59 <li><a href="tests/crosshair.html">Crosshairs</a></li>
60 <li><a href="tests/hourly.html">Hourly/Minutely data</a></li>
61 <li><a href="tests/isolated-points.html">Isolated Points</a></li>
62 <li><a href="tests/missing-data.html">Missing Data</a></li>
63 <li><a href="tests/border.html">Bordered chart</a></li>
64 <li><a href="tests/custom-bars.html">Custom Bars</a></li>
65 <li><a href="tests/customLabel.html">Custom Label Styles</a></li>
66 <li><a href="tests/dygraph.html">Minimal Example</a></li>
67 <li><a href="tests/negative.html">Negative Numbers</a></li>
68 <li><a href="tests/noise.html">Noisy Data</a></li>
69 <li><a href="tests/two-series.html">Multiple Series</a></li>
a7ef12f5 70 <li><a href="tests/highlighted-region.html">Custom Underlay / background</a></li>
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71 </ul>
72 </div>
fe57a69b 73
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74 <div id="content">
75 <h1>dygraphs JavaScript Visualization Library</h1>
68f9bed3 76
15c966e0 77 <p><a href="http://github.com/danvk/dygraphs">http://github.com/danvk/dygraphs</a></p>
a843ade7 78 <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>
68f9bed3 79
15c966e0 80 <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>
68f9bed3 81
15c966e0 82 <h3 id="demo">A demo is worth a thousand words:</h3>
68f9bed3 83
15c966e0 84 <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>
68f9bed3 85
15c966e0 86 <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>
68f9bed3 87
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88 <div id="demodiv" style="width:800px; height:320px;"></div>
89 <script type="text/javascript">
68f9bed3 90 g = new Dygraph(
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91 document.getElementById("demodiv"),
92 "ny-vs-sf.txt",
93 {
94 rollPeriod: 14,
95 showRoller: true,
96 customBars: true,
97 yAxisLabelWidth: 30
98 }
68f9bed3 99 );
15c966e0 100 </script>
68f9bed3 101
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102 <h4>Some things to notice:</h4>
103 <ul>
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104 <li>There's less seasonal temperature variation in SF than in NY.</li>
105 <li>The difference is about 15&deg; F for SF vs. 50&deg; F for NY.</li>
106 <li>The daily data (set rolling period to 1) is quite noisy and hides this conclusion.</li>
107 <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>
108 <li>There's a gap in the data for SF, when the weather station was down (zoom into October 2007 to see it).</li>
109 <li>The bands around each point indicate average highs and lows.</li>
110 <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>
15c966e0 111 </ul>
68f9bed3 112
15c966e0 113 <p>dygraphs allows the user to explore the data and discover these facts.</p>
68f9bed3 114
15c966e0 115 <p>For more demos, browse the dygraph <a href="tests/">tests</a> directory.</p>
68f9bed3 116
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117 <h3>Features</h3>
118 <p>Some of the features of dygraphs:</p>
119 <ul>
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120 <li>Plots time series without using an external server or Flash</li>
121 <li>Works in Internet Explorer (using excanvas)</li>
2b2a2f1c 122 <li>Lightweight (57kb) and responsive</li>
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123 <li>Displays values on mouseover (this makes it easily discoverable)</li>
124 <li>Supports error bands around data series</li>
125 <li>Interactive zoom</li>
2b2a2f1c 126 <li>Displays Annotations on the chart</li>
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127 <li>Adjustable averaging period</li>
128 <li>Can intelligently chart fractions</li>
129 <li>Customizable click-through actions</li>
130 <li>Compatible with the Google Visualization API</li>
131 <li>Intelligent defaults make it easy to use</li>
15c966e0 132 </ul>
68f9bed3 133
15c966e0 134 <h2 id="usage">Usage</h2>
68f9bed3 135
15c966e0 136 <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>
68f9bed3 137
15c966e0 138 <p>Here's a basic example to get things started:</p>
68f9bed3 139
15c966e0 140 <div class="example" style="clear:both;">
68f9bed3 141 <div class="codeblock" style="float:left;width:400px;">
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142 <h3 style="text-align:center">HTML</h3>
143 <code>
144 <pre>
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145&lt;html&gt;
146&lt;head&gt;
68f9bed3 147&lt;script type=&quot;text/javascript&quot;
15c966e0 148 src=&quot;dygraph-combined.js&quot;&gt;&lt;/script&gt;
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149&lt;/head&gt;
150&lt;body&gt;
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151&lt;div id=&quot;graphdiv&quot;&gt;&lt;/div&gt;
152&lt;script type=&quot;text/javascript&quot;&gt;
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153 g = new Dygraph(
154
155 // containing div
156 document.getElementById(&quot;graphdiv&quot;),
157
158 // CSV or path to a CSV file.
159 &quot;Date,Temperature\n&quot; +
160 &quot;2008-05-07,75\n&quot; +
161 &quot;2008-05-08,70\n&quot; +
162 &quot;2008-05-09,80\n&quot;
163
164 );
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165&lt;/script&gt;
166&lt;/body&gt;
167&lt;/html&gt;
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168</pre>
169 </code>
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170 </div>
171 <div class="codeoutput" style="float:left;">
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172 <h3 style="text-align:center">OUTPUT</h3>
173 <div id="graphdiv"></div>
174 <script type="text/javascript">
175 g = new Dygraph(
176
177 // containing div
178 document.getElementById("graphdiv"),
179
180 // CSV or path to a CSV file.
181 "Date,Temperature\n" +
182 "2008-05-07,75\n" +
183 "2008-05-08,70\n" +
184 "2008-05-09,80\n"
185 );
186 </script>
68f9bed3 187 </div>
15c966e0 188 </div>
68f9bed3 189
ff00d3e2 190 <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>
68f9bed3 191
15c966e0 192 <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>
68f9bed3 193
15c966e0 194 <div class="example" style="clear:both;">
68f9bed3 195 <div class="codeblock" style="float:left;width:400px;">
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196 <h3 style="text-align:center">HTML</h3>
197 <code>
68f9bed3 198<pre>
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199&lt;html&gt;
200&lt;head&gt;
68f9bed3 201&lt;script type=&quot;text/javascript&quot;
15c966e0 202 src=&quot;dygraph-combined.js&quot;&gt;&lt;/script&gt;
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203&lt;/head&gt;
204&lt;body&gt;
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205&lt;div id=&quot;graphdiv2&quot;
206 style=&quot;width:500px; height:300px;&quot;&gt;&lt;/div&gt;
207&lt;script type=&quot;text/javascript&quot;&gt;
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208 g2 = new Dygraph(
209 document.getElementById(&quot;graphdiv2&quot;),
210 &quot;temperatures.csv&quot;, // path to CSV file
211 {} // options
212 );
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213&lt;/script&gt;
214&lt;/body&gt;
215&lt;/html&gt;
216</pre>
15c966e0 217 </code>
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218 </div>
219 <div class="codeoutput" style="float:left;">
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220 <h3 style="text-align:center">OUTPUT</h3>
221 <div id="graphdiv2" style="width:500px; height:300px;"></div>
222 <script type="text/javascript">
223 g2 = new Dygraph(
224 document.getElementById("graphdiv2"),
225 "temperatures.csv",
226 {}
227 );
228 </script>
68f9bed3 229 </div>
15c966e0 230 </div>
68f9bed3 231
15c966e0 232 <p style="clear:both;">The file used is <code><a href="temperatures.csv">temperatures.csv</a></code>.</p>
68f9bed3 233
15c966e0 234 <p>There are a few things to note here:</p>
68f9bed3 235
15c966e0 236 <ul>
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237 <li>The Dygraph sent off an XHR to get the temperatures.csv file.</li>
238 <li>The labels were taken from the first line of <code>temperatures.csv</code>, which is <code>Date,High,Low</code>.</li>
239 <li>The Dygraph automatically chose two different, easily-distinguishable colors for the two data series.</li>
240 <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>
241 <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>
242 <li>The data is very spiky. A moving average would be easier to interpret.</li>
15c966e0 243 </ul>
68f9bed3 244
15c966e0 245 <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>
68f9bed3 246
15c966e0 247 <div class="example" style="clear:both;">
68f9bed3 248 <div class="codeblock" style="float:left;width:400px;">
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249 <h3 style="text-align:center">HTML</h3>
250 <code>
68f9bed3 251<pre>
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252&lt;html&gt;
253&lt;head&gt;
68f9bed3 254&lt;script type=&quot;text/javascript&quot;
15c966e0 255 src=&quot;dygraph-combined.js&quot;&gt;&lt;/script&gt;
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256&lt;/head&gt;
257&lt;body&gt;
68f9bed3 258&lt;div id=&quot;graphdiv3&quot;
15c966e0 259 style=&quot;width:500px; height:300px;&quot;&gt;&lt;/div&gt;
68f9bed3 260&lt;script type=&quot;text/javascript&quot;&gt;
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261 g3 = new Dygraph(
262 document.getElementById(&quot;graphdiv3&quot;),
263 &quot;temperatures.csv&quot;,
264 {
265 rollPeriod: 7,
266 showRoller: true
267 }
268 );
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269&lt;/script&gt;
270&lt;/body&gt;
271&lt;/html&gt;
272</pre>
15c966e0 273 </code>
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274 </div>
275 <div class="codeoutput" style="float:left;">
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276 <h3 style="text-align:center">OUTPUT</h3>
277 <div id="graphdiv3" style="width:500px; height:300px;"></div>
278 <script type="text/javascript">
279 g3 = new Dygraph(
280 document.getElementById("graphdiv3"),
281 "temperatures.csv",
282 {
283 rollPeriod: 7,
284 showRoller: true
285 }
286 );
287 </script>
68f9bed3 288 </div>
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289 </div>
290
291 <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>
68f9bed3 292
15c966e0 293 <h2>Error Bars</h2>
68f9bed3 294
15c966e0 295 <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>
68f9bed3 296
15c966e0 297 <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>
68f9bed3 298
15c966e0 299 <div class="example" style="clear:both;">
68f9bed3 300 <div class="codeblock" style="float:left;width:400px;">
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301 <h3 style="text-align:center">HTML</h3>
302 <code>
68f9bed3 303<pre>
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304&lt;html&gt;
305&lt;head&gt;
68f9bed3 306&lt;script type=&quot;text/javascript&quot;
15c966e0 307 src=&quot;combined.js&quot;&gt;&lt;/script&gt;
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308&lt;/head&gt;
309&lt;body&gt;
68f9bed3 310&lt;div id=&quot;graphdiv4&quot;
15c966e0 311 style=&quot;width:600px; height:300px;&quot;&gt;&lt;/div&gt;
68f9bed3 312&lt;script type=&quot;text/javascript&quot;&gt;
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313 g4 = new Dygraph(
314 document.getElementById(&quot;graphdiv4&quot;),
315 &quot;twonormals.csv&quot;,
316 {
317 rollPeriod: 7,
318 showRoller: true,
319 errorBars: true,
320 valueRange: [50,125]
321 }
322 );
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323&lt;/script&gt;
324&lt;/body&gt;
325&lt;/html&gt;
326</pre>
15c966e0 327 </code>
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328 </div>
329 <div class="codeoutput" style="float:left;">
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330 <h3 style="text-align:center">OUTPUT</h3>
331 <div id="graphdiv4" style="width:600px; height:300px;"></div>
332 <script type="text/javascript">
333 g4 = new Dygraph(
334 document.getElementById("graphdiv4"),
335 "twonormals.csv",
336 {
337 rollPeriod: 7,
338 showRoller: true,
339 errorBars: true,
340 valueRange: [50,125]
341 }
342 );
343 </script>
68f9bed3 344 </div>
15c966e0 345 </div>
68f9bed3 346
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347 <p style="clear:both;">Things to note here:</p>
348
349 <ul>
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350 <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>
351 <li>The first line of the CSV file doesn't mention the error columns. In this case, it's just "Date,Series1,Series2".</li>
352 <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>
353 <li>The error bars are partially transparent. This can be seen when they overlap one another.</li>
15c966e0 354 </ul>
68f9bed3 355
15c966e0 356 <h2 id="ie">Internet Explorer Compatibility</h2>
68f9bed3 357
15c966e0 358 <p>The dygraphs library relies heavily on HTML's <code>&lt;canvas&gt;</code> tag, which Microsoft Internet Explorer does not support. Fortunately, some clever engineers created the <a href="http://code.google.com/p/explorercanvas/">excanvas</a> library, which implements the <code>&lt;canvas&gt;</code> tag in IE using VML.</p>
435c59c9 359
15c966e0 360 <p>You can add IE support to any page using dygraphs by including the following in your page:</p>
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361
362<pre>
363&lt;head&gt;
15c966e0 364 &lt;!--[if IE]&gt;&lt;script src="excanvas.js"&gt;&lt;/script&gt;&lt;![endif]--&gt;
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365&lt;/head&gt;
366</pre>
367
15c966e0 368 <p>This works quite well in practice. Charts are responsive, even under VML emulation.</p>
435c59c9 369
15c966e0 370 <p>One common gotcha to look out for: make sure you don't have any trailing commas in parameter lists, e.g.</p>
435c59c9 371
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372<pre>
373new Dygraph(el, data, {
15c966e0 374 showRoller: true, // note trailing comma
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375})</pre>
376
68f9bed3 377 <p>Most browsers will ignore the trailing comma, but it will break under IE.</p>
aaa21dc9 378
68f9bed3 379 <h2 id="gviz">GViz Data</h2>
435c59c9 380
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381 <p>The <a
382 href="http://code.google.com/apis/visualization/documentation/index.html">Google
383 Visualization API</a> provides a standard interface for describing data.
384 Once you've specified your data using this API, you can plug in any
385 GViz-compatible visualization. dygraphs is such a visualization. In
386 particular, it can be used as a drop-in replacement for the
387 AnnotatedTimeline visualization used on Google Finance and other sites. To
388 see how this works, check out the <a href="tests/annotation-gviz.html">gviz
389 annotation demo.</a></p>
36676109 390
68f9bed3 391 <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>
36676109 392
68f9bed3 393 <p>Here's an example of a published gviz gadget using dygraphs:</p>
a87e8e01 394
15c966e0 395 <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>
a87e8e01 396
68f9bed3 397 <h2 id="baseball">Charting Fractions</h2>
15c966e0 398
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399 <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>
400
401 <ul>
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402 <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>
403 <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>
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404 </ul>
405
406 <p>Fortunately, dygraphs handles both of these for you! Here's a chart and the command that generated it:</p>
407
408 <div style="width:750px; text-align:center; font-weight: bold; font-size: 125%;">Batting Average for Ichiro Suzuki vs. Mariners (2004)</div>
409 <div id="baseballdiv" style="width:750px; height:300px;"></div>
410 <script type="text/javascript">
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411 new Dygraph(
412 document.getElementById("baseballdiv"),
413 "suzuki-mariners.txt",
414 {
415 fractions: true,
416 errorBars: true,
417 showRoller: true,
418 rollPeriod: 15
419 }
420 );
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421 </script>
422
423 <p>Command:</p>
a87e8e01 424<pre>
15c966e0 425 new Dygraph(
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426 document.getElementById(&quot;baseballdiv&quot;),
427 &quot;suzuki-mariners.txt&quot;,
428 {
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429 fractions: true,
430 errorBars: true,
431 showRoller: true,
432 rollPeriod: 15
68f9bed3 433 }
15c966e0 434 );
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435</pre>
436
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437 <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>
438
439 <p>A couple things to notice about this chart:</p>
15c966e0 440
68f9bed3 441 <ul>
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442 <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>
443 <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>
444 <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>
445 <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>
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446 </ul>
447
448 <h2 id="stock">One last demo</h2>
449
450 <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>
451
452 <div id="dow_chart" style="width:900px; height:350px;"></div>
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453 <p><b>Display: </b>
454 <input type=checkbox id=0 onClick="stockchange(this)" checked>
455 <label for="0"> Nominal</label>
456 <input type=checkbox id=1 onClick="stockchange(this)" checked>
457 <label for="1"> Real</label>
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458 <input type=checkbox id=ann onClick="annotationschange(this)" checked>
459 <label for="ann"> Annotations</label>
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460 </p>
461
68f9bed3 462 <script type="text/javascript">
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463 var stock_annotations = [
464 {
465 series: "Real",
466 x: "1929-08-15",
467 shortText: "A",
468 text: "1929 Stock Market Peak"
469 },
470 {
471 series: "Nominal",
472 x: "1987-08-15",
473 shortText: "B",
474 text: "1987 Crash"
475 },
476 {
477 series: "Nominal",
478 x: "1999-12-15",
479 shortText: "C",
480 text: "1999 (.com) Peak"
481 },
482 {
483 series: "Nominal",
484 x: "2007-10-15",
485 shortText: "D",
486 text: "All-Time Market Peak"
487 }
488 ];
489
15c966e0 490 // From http://www.econstats.com/eqty/eq_d_mi_3.csv
7ffbfdc1 491 stockchart = new Dygraph(
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492 document.getElementById('dow_chart'),
493 "dow.txt",
494 {
495 showRoller: true,
496 customBars: true,
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497 labelsKMB: true,
498 drawCallback: function(g, is_initial) {
499 if (!is_initial) return;
500 g.setAnnotations( stock_annotations );
501 }
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502 }
503 );
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504
505 function stockchange(el) {
506 stockchart.setVisibility(el.id, el.checked);
507 }
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508
509 function annotationschange(el) {
510 if (el.checked) {
511 stockchart.setAnnotations(stock_annotations);
512 } else {
513 stockchart.setAnnotations([]);
514 }
515 }
68f9bed3 516 </script>
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517<!--
518
519Here is a script to regenerate the Dow Jones plot:
520
521# Get unadjusted DJIA data in a nice format:
522curl -O http://www.econstats.com/eqty/eq_d_mi_3.csv
523sed '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
524
525# Fetch and format the CPI data:
526curl '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
527sed '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-$2\t/g' > cpi-u.tsv
528
529# Merge:
15c966e0 530join -t' ' cpi-u.tsv monthly-djia.tsv > annotated-djia.tsv
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531perl -ne 'BEGIN{print "Month,Nominal,Real\n"} chomp; ($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
532
533-->
353a0294 534
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535 <h2 id="options">Other Options</h2>
536
7e6fad88 537 <p>These are the options that can be passed in through the optional third parameter of the Dygraph constructor. Under each option is a set of links to tests which demonstrate its use. While we attempt to keep this list up-to-date, a more complete list can be found in the <code>Dygraph.DEFAULT_ATTRS</code> map in <code>dygraph.js</code> and the <code>this.options</code> map in <code>dygraph-canvas.js</code>.</p>
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538
539 <table class="thinborder" width="900">
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540 <thead>
541 <tr>
542 <th width="150">Name</th>
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543 <th width="200">Values</th>
544 <th width="150">Default</th>
545 <th>Description</th>
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546 </tr>
547 </thead>
548 <tbody>
549 <tr>
550 <td><strong>includeZero</strong></td>
551 <td><code>boolean</code></td>
552 <td><code>false</code></td>
dde90a16 553 <td>Usually, dygraphs will use the range of the data plus some padding to set the range of the y-axis. If this option is set, the y-axis will always include zero, typically as the lowest value. This can be used to avoid exaggerating the variance in the data.
939ecc46 554 <div class="tests">Tests: <a href="tests/no-range.html">no-range</a> <a href="tests/numeric-gviz.html">numeric-gviz</a> <a href="tests/small-range-zero.html">small-range-zero</a> </div>
dde90a16 555 </td>
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556 </tr>
557 <tr>
558 <td><strong>rollPeriod</strong></td>
8c851a1b 559 <td><code>integer &gt;= 1</code></td>
15c966e0 560 <td><code>1</code></td>
dde90a16 561 <td>Number of days over which to average data. Discussed extensively above.
939ecc46 562 <div class="tests">Tests: <a href="tests/demo.html">demo</a> <a href="tests/two-series.html">two-series</a> <a href="tests/noise.html">noise</a> </div>
dde90a16 563 </td>
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564 </tr>
565 <tr>
566 <td><strong>showRoller</strong></td>
567 <td><code>boolean</code></td>
568 <td><code>false</code></td>
dde90a16 569 <td>If the rolling average period text box should be shown.
1bc2103a 570 <div class="tests">Tests: <a href="tests/callback.html">callback</a> <a href="tests/crosshair.html">crosshair</a> <a href="tests/fractions.html">fractions</a> <a href="tests/isolated-points.html">isolated-points</a> <a href="tests/numeric-gviz.html">numeric-gviz</a> <a href="tests/underlay-callback.html">underlay-callback</a> <a href="tests/highlighted-region.html">highlighted-region</a></div>
dde90a16 571 </td>
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572 </tr>
573 <tr>
574 <td><strong>colors</strong></td>
575 <td><code>['red', '#00FF00']</code></td>
576 <td><code></code></td>
dde90a16 577 <td>List of colors for the data series. These can be of the form "#AABBCC" or "rgb(255,100,200)" or "yellow", etc. If not specified, equally-spaced points around a color wheel are used.
939ecc46 578 <div class="tests">Tests: <a href="tests/color-visibility.html">color-visibility</a> <a href="tests/demo.html">demo</a> </div>
dde90a16 579 </td>
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580 </tr>
581 <tr>
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582 <td><strong>fillGraph</strong></td>
583 <td><code>boolean<br/></code></td>
f3975624 584 <td><code>false</code></td>
8c851a1b 585 <td>Should the area underneath the graph be filled? This option is not
dde90a16 586 compatible with error bars.
939ecc46 587 <div class="tests">Tests: <a href="tests/fillGraph.html">fillGraph</a> </div>
dde90a16 588 </td>
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589 </tr>
590 <tr>
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591 <td><strong>visibility</strong></td>
592 <td><code>Array of booleans<br/></code></td>
593 <td><code>[true, true, ...]</code></td>
594 <td>Which series should initially be visible? Once the Dygraph has
595 been constructed, you can access and modify the visibility of each
596 series using the <code>visibility</code> and
dde90a16 597 <code>setVisibility</code> methods.
939ecc46 598 <div class="tests">Tests: <a href="tests/visibility.html">visibility</a> <a href="tests/color-visibility.html">color-visibility</a> </div>
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599 </td>
600 </tr>
601 <tr>
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602 <td><strong>colorSaturation</strong></td>
603 <td><code>0.0 - 1.0</code></td>
604 <td><code>1.0</code></td>
dde90a16 605 <td>If <strong>colors</strong> is not specified, saturation of the automatically-generated data series colors.
bf5b5f4d 606 <div class="tests">Tests: <font color=red>none</font></div>
dde90a16 607 </td>
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608 </tr>
609 <tr>
610 <td><strong>colorValue</strong></td>
611 <td><code>float (0.0 &mdash; 1.0)</code></td>
612 <td><code>1.0</code></td>
dde90a16 613 <td>If colors is not specified, value of the data series colors, as in hue/saturation/value. (0.0-1.0, default 0.5)
bf5b5f4d 614 <div class="tests">Tests: <font color=red>none</font></div>
dde90a16 615 </td>
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616 </tr>
617 <tr>
618 <td><strong>clickCallback</strong></td>
619 <td><code>function(e, date){<br>&nbsp;&nbsp;&nbsp;&nbsp;alert(date);<br>}</code></td>
620 <td><code>null</code></td>
dde90a16 621 <td>A function to call when a data point is clicked. The function should take two arguments, the event object for the click and the date that was clicked. (default null)
939ecc46 622 <div class="tests">Tests: <a href="tests/callback.html">callback</a> </div>
dde90a16 623 </td>
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624 </tr>
625 <tr>
626 <td><strong>zoomCallback</strong></td>
0c75dc72 627 <td><code>function(minDate,<br/>maxDate){}</code></td>
15c966e0 628 <td><code>null</code></td>
dde90a16 629 <td>A function to call when the zoom window is changed (either by zooming in or out). minDate and maxDate are milliseconds since epoch.
939ecc46 630 <div class="tests">Tests: <a href="tests/callback.html">callback</a> </div>
dde90a16 631 </td>
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632 </tr>
633 <tr>
634 <td><strong>strokeWidth</strong></td>
635 <td><code>integer</code></td>
636 <td><code>1</code></td>
dde90a16 637 <td>Width of the data lines. This can be used to increase the contrast or some graphs.
bf5b5f4d 638 <div class="tests">Tests: <font color=red>none</font></div>
dde90a16 639 </td>
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640 </tr>
641 <tr>
642 <td><strong>dateWindow</strong></td>
643 <td><code>[<br>&nbsp;&nbsp;Date.parse('2006-01-01'),<br>&nbsp;&nbsp;(new Date()).valueOf()<br>]</code></td>
0c75dc72 644 <td rowspan="2"><code>Full range of the<br/> input is shown</code></td>
dde90a16 645 <td>Initially zoom in on a section of the graph. Is of the form [earliest, latest], where earliest/latest are milliseconds since epoch.
939ecc46 646 <div class="tests">Tests: <a href="tests/dateWindow.html">dateWindow</a> <a href="tests/link-interaction.html">link-interaction</a> </div>
dde90a16 647 </td>
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648 </tr>
649 <tr>
650 <td><strong>valueRange</strong></td>
651 <td><code>[10, 110]</code></td>
dde90a16 652 <td>Explicitly set the vertical range of the graph to [low, high].
bf5b5f4d 653 <div class="tests">Tests: <font color=red>none</font></div>
dde90a16 654 </td>
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655 </tr>
656 <tr>
657 <td><strong>labelsSeparateLines</strong></td>
658 <td><code>boolean</code></td>
659 <td><code>false</code></td>
dde90a16 660 <td>Put <code>&lt;br/&gt;</code> between lines in the label string. Often used in conjunction with <strong>labelsDiv</strong>.
939ecc46 661 <div class="tests">Tests: <a href="tests/customLabel.html">customLabel</a> <a href="tests/demo.html">demo</a> </div>
dde90a16 662 </td>
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663 </tr>
664 <tr>
665 <td><strong>labelsDiv</strong></td>
52fe05c1 666 <td><code style="font-size: small">document.getElementById('foo')</code><br/>or<br/><code>'foo'</code></td>
15c966e0 667 <td><code>null</code></td>
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668 <td style="vertical-align:top">Show data labels in an external div, rather than on the graph. This value can either be a div element or a div id.
669 <div class="tests">Tests: <a href="tests/label-div.html">label-div</a> </div>
670 </td>
671 </tr>
672 <tr>
673 <td><strong>labelsShowZeroValues</strong></td>
674 <td><code>boolean</code></td>
675 <td><code>true</code></td>
676 <td>Show zero value labels in the labelsDiv.
677 <div class="tests">Tests: <a href="tests/label-div.html">label-div</a> </div>
dde90a16 678 </td>
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679 </tr>
680 <tr>
681 <td><strong>labelsKMB</strong></td>
682 <td><code>true</code></td>
683 <td><code>false</code></td>
dde90a16 684 <td>Show K/M/B for thousands/millions/billions on y-axis.
939ecc46 685 <div class="tests">Tests: <a href="tests/demo.html">demo</a> <a href="tests/labelsKMB.html">labelsKMB</a> <a href="tests/no-range.html">no-range</a> </div>
dde90a16 686 </td>
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687 </tr>
688 <tr>
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689 <td><strong>labelsKMG2</strong></td>
690 <td><code>true</code></td>
691 <td><code>false</code></td>
692 <td>Show k/M/G for kilo/Mega/Giga on y-axis. This is different than
dde90a16 693 <code>labelsKMB</code> in that it uses base 2, not 10.
939ecc46 694 <div class="tests">Tests: <a href="tests/labelsKMB.html">labelsKMB</a> </div>
dde90a16 695 </td>
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696 </tr>
697 <tr>
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698 <td><strong>labelsDivWidth</strong></td>
699 <td><code>250</code></td>
700 <td><code></code></td>
dde90a16 701 <td>Width (in pixels) of the div which shows information on the currently-highlighted points.
939ecc46 702 <div class="tests">Tests: <a href="tests/customLabel.html">customLabel</a> </div>
dde90a16 703 </td>
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704 </tr>
705 <tr>
706 <td><strong>labelsDivStyles</strong></td>
707 <td><code>{}</code></td>
708 <td><code>null</code></td>
dde90a16 709 <td>Additional styles to apply to the currently-highlighted points div. For example, { 'font-weight': 'bold' } will make the labels bold.
939ecc46 710 <div class="tests">Tests: <a href="tests/border.html">border</a> <a href="tests/customLabel.html">customLabel</a> </div>
dde90a16 711 </td>
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712 </tr>
713 <tr>
714 <td><strong>highlightCircleSize</strong></td>
715 <td><code>integer</code></td>
716 <td><code>3</code></td>
dde90a16 717 <td>The size in pixels of the dot drawn over highlighted points.
939ecc46 718 <div class="tests">Tests: <a href="tests/grid_dot.html">grid_dot</a> </div>
dde90a16 719 </td>
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720 </tr>
721 <tr>
722 <td><strong>drawPoints</strong></td>
723 <td><code>boolean</code></td>
724 <td><code>false</code></td>
dde90a16 725 <td>Draw a small dot at each point, in addition to a line going through the point. This makes the individual data points easier to see, but can increase visual clutter in the chart.
939ecc46 726 <div class="tests">Tests: <a href="tests/draw-points.html">draw-points</a> </div>
dde90a16 727 </td>
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728 </tr>
729 <tr>
730 <td><strong>pointSize</strong></td>
731 <td><code>interger</code></td>
732 <td><code>1</code></td>
dde90a16 733 <td>The size of the dot to draw on each point in pixels (see drawPoints). A dot is always drawn when a point is "isolated", i.e. there is a missing point on either side of it. This also controls the size of those dots.
bf5b5f4d 734 <div class="tests">Tests: <font color=red>none</font></div>
dde90a16 735 </td>
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736 </tr>
737 <tr>
738 <td><strong>pixelsPerXLabel</strong></td>
739 <td rowspan="2"><code>integer</code></td>
740 <td><code>60</code></td>
dde90a16 741 <td rowspan="2">Number of pixels to require between each x- and y-label. Larger values will yield a sparser axis with fewer ticks.
939ecc46 742 <div class="tests">Tests: <a href="tests/spacing.html">spacing</a> </div>
dde90a16 743 </td>
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744 </tr>
745 <tr>
746 <td><strong>pixelsPerYLabel</strong></td>
747 <td><code>30</code></td>
748 </tr>
749 <tr>
750 <td><strong>xAxisLabelWidth</strong></td>
751 <td rowspan="2"><code>integer</code></td>
752 <td><code></code></td>
dde90a16 753 <td rowspan="2">Width (in pixels) of the x- and y-axis labels.
939ecc46 754 <div class="tests">Tests: <a href="tests/customLabel.html">customLabel</a> </div>
dde90a16 755 </td>
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756 </tr>
757 <tr>
758 <td><strong>yAxisLabelWidth</strong></td>
759 <td><code></code></td>
760 </tr>
761 <tr>
762 <td><strong>axisLabelFontSize</strong></td>
763 <td><code>integer</code></td>
764 <td><code>14</code></td>
dde90a16 765 <td>Size of the font (in pixels) to use in the axis labels, both x- and y-axis.
bf5b5f4d 766 <div class="tests">Tests: <font color=red>none</font></div>
dde90a16 767 </td>
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768 </tr>
769 <tr>
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770 <td><strong>xAxisLabelFormatter</strong></td>
771 <td><code>function(date, granularity)</code></td>
772 <td><code>Dygraph.dateAxisFormatter</code></td>
773 <td>Function to call to format values along the x axis.
774 <div class="tests">Tests: <a href="tests/x-axis-formatter.html">xAxisLabelFormatter</a></div>
775 </td>
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776 </tr>
777 <tr>
778 <td><strong>yAxisLabelFormatter</strong></td>
779 <td><code>function(x)</code></td>
780 <td><code>yValueFormatter</code></td>
781 <td>
782 Function used to format values along the Y axis. By default it uses the same as the <code>yValueFormatter</code> unless specified.
783 <div class="tests">Tests: <a href="tests/y-axis-formatter.html">yAxisLabelFormatter</a></div>
784 </td>
785 </tr>
31eddad3 786 <tr>
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787 <td><strong>rightGap</strong></td>
788 <td><code>integer</code></td>
789 <td><code></code></td>
dde90a16 790 <td>Number of pixels to leave blank at the right edge of the Dygraph. This makes it easier to highlight the right-most data point.
bf5b5f4d 791 <div class="tests">Tests: <font color=red>none</font></div>
dde90a16 792 </td>
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793 </tr>
794 <tr>
795 <td><strong>errorBars</strong></td>
796 <td><code>boolean</code></td>
797 <td><code>false</code></td>
dde90a16 798 <td>Does the data contain standard deviations? Setting this to true alters the input format (see above).
939ecc46 799 <div class="tests">Tests: <a href="tests/noise.html">noise</a> <a href="tests/customLabel.html">customLabel</a> <a href="tests/draw-points.html">draw-points</a> <a href="tests/fillGraph.html">fillGraph</a> <a href="tests/fractions.html">fractions</a> </div>
dde90a16 800 </td>
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801 </tr>
802 <tr>
803 <td><strong>sigma</strong></td>
804 <td><code>integer</code></td>
805 <td><code></code></td>
dde90a16 806 <td>When errorBars is set, shade this many standard deviations above/below each point.
bf5b5f4d 807 <div class="tests">Tests: <font color=red>none</font></div>
dde90a16 808 </td>
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809 </tr>
810 <tr>
811 <td><strong>fractions</strong></td>
812 <td><code>boolean</code></td>
813 <td><code>false</code></td>
dde90a16 814 <td>When set, attempt to parse each cell in the CSV file as "a/b", where a and b are integers. The ratio will be plotted. This allows computation of Wilson confidence intervals (see below).
939ecc46 815 <div class="tests">Tests: <a href="tests/fractions.html">fractions</a> </div>
dde90a16 816 </td>
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817 </tr>
818 <tr>
819 <td><strong>wilsonInterval</strong></td>
820 <td><code>boolean</code></td>
821 <td><code>true</code></td>
dde90a16 822 <td>Use in conjunction with the "fractions" option. Instead of plotting +/- N standard deviations, dygraphs will compute a Wilson confidence interval and plot that. This has more reasonable behavior for ratios close to 0 or 1.
bf5b5f4d 823 <div class="tests">Tests: <font color=red>none</font></div>
dde90a16 824 </td>
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825 </tr>
826 <tr>
827 <td><strong>customBars</strong></td>
828 <td><code>boolean</code></td>
829 <td><code>false</code></td>
dde90a16 830 <td>When set, parse each CSV cell as "low;middle;high". Error bars will be drawn for each point between low and high, with the series itself going through middle.
939ecc46 831 <div class="tests">Tests: <a href="tests/custom-bars.html">custom-bars</a> <a href="tests/zero-series.html">zero-series</a> </div>
dde90a16 832 </td>
15c966e0 833 </tr>
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834
835 <tr>
836 <td><strong>drawCallback</strong></td>
837 <td><code>function(dygraph, is_initial)</code></td>
838 <td><code>null</code></td>
839 <td>When set, this callback gets called every time the dygraph is drawn. This includes the initial draw, after zooming and repeatedly while panning. The first parameter is the dygraph being drawn. The second is a boolean value indicating whether this is the initial draw.
2322a4ca 840 <div class="tests">Tests: <a href="tests/callback.html">callback</a> <a href="tests/synchronize.html">synchronize</a> </div>
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841 </td>
842 </tr>
843
844 <tr>
845 <td><strong>gridLineColor</strong></td>
846 <td><code>red, blue</code></td>
847 <td><code>rgb(128,128,128)</code></td>
848 <td>The color of the gridlines.
2322a4ca 849 <div class="tests">Tests: <a href="tests/grid_dot.html">grid_dot</a> </div>
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850 </td>
851 </tr>
852
853 <tr>
854 <td><strong>highlightCallback</strong></td>
855 <td><code>function(event, x, points)</code></td>
a4c6a67c 856 <td><code>null</code></td>
85cda1ca 857 <td>When set, this callback gets called every time a new point is highlighted. The parameters are the JavaScript mousemove event, the x-coordinate of the highlighted points and an array of highlighted points: <code>[ {name: 'series', yval: y-value}, &hellip; ]</code>
2322a4ca 858 <div class="tests">Tests: <a href="tests/callback.html">callback</a> <a href="tests/crosshair.html">crosshair</a> </div>
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859 </td>
860 </tr>
861
862 <tr>
863 <td><strong>unhighlightCallback</strong></td>
864 <td><code>function(event)</code></td>
865 <td><code>null</code></td>
866 <td>When set, this callback gets called every time the user stops highlighting any point by mousing out of the graph. The parameter is the mouseout event.
867 <div class="tests">Tests: <a href="tests/callback.html">callback</a> <a href="tests/crosshair.html">crosshair</a> </div>
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868 </td>
869 </tr>
870
871 <tr>
872 <td><strong>strokeWidth</strong></td>
873 <td><code>0.5, 2.0</code></td>
874 <td><code>1.0</code></td>
875 <td>The width of the lines connecting data points.
2322a4ca 876 <div class="tests">Tests: <a href="tests/grid_dot.html">grid_dot</a> </div>
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877 </td>
878 </tr>
879
880 <tr>
881 <td><strong>width</strong></td>
882 <td rowspan="2"><code>integer</code></td>
883 <td><code>480</code></td>
884 <td rowspan="2">Width/Height (in pixels) of the chart. If the container div has been explicitly sized, these attributes will be ignored.
2322a4ca 885 <div class="tests">Tests: <a href="tests/demo.html">demo</a> <a href="tests/link-interaction.html">link-interaction</a> <a href="tests/no-range.html">no-range</a> </div>
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886 </td>
887 </tr>
888 <tr>
889 <td><strong>height</strong></td>
890 <td><code>320</code></td>
891 </tr>
892
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893 <tr>
894 <td><strong>stepPlot</strong></td>
895 <td><code>boolean</code></td>
896 <td><code>false</code></td>
897 <td>
898 When set, display the graph as a step plot instead of a line plot.
899 <div class="tests">Tests: <a href="tests/steps.html">steps</a></div>
900 </td>
901 </tr>
902
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903 <tr>
904 <td><strong>xValueFormatter</strong></td>
905 <td><code>function(x)</code></td>
906 <td></td>
907 <td>
908 Function to provide a custom display format the X value for mouseover.
909 </td>
910 </tr>
911
912 <tr>
913 <td><strong>yValueFormatter</strong></td>
914 <td><code>function(x)</code></td>
915 <td>(Round to 2 decimal places)</td>
916 <td>
917 Function to provide a custom display format for the Y value for mouseover.
918 <div class="tests">Tests: <a href="tests/y-axis-formatter.html">yAxisLabelFormatter</a></div>
919 </td>
920 </tr>
921
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922 <tr>
923 <td><strong>avoidMinZero</strong></td>
924 <td><code>boolean</code></td>
925 <td><code>false</code></td>
926 <td>
927 When set, the heuristic that fixes the Y axis at zero for a data set with the minimum Y value of zero is disabled.
928 This is particularly useful for data sets that contain many zero values, especially for step plots which may otherwise have lines not visible running along the bottom axis.
929 <div class="tests">Tests: <a href="tests/avoidMinZero.html">avoidMinZero</a></div>
930 </td>
931 </tr>
932
15c966e0 933 </tbody>
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934 </table>
935
936 <h2>Common Gotchas</h2>
937
938 <p>Here are a few problems that I've frequently run into while using the dygraphs library.</p>
939
940 <ul>
dde90a16 941 <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>
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942 <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>
943 <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>
944 <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>
945 <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>
946 <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>
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947 </ul>
948
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949 <h2 id="gwt">GWT Compatibility</h2>
950 <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>
951
952<pre>
953&lt;inherits name=&quot;org.danvk.dygraphs&quot;/&gt;
954</pre>
955
956 <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>
957
958<pre>
fb369f35 959 public static native JavaScriptObject drawDygraph(Element element, DataTable dataTable, double minY, double maxY) /*-{
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960 var chart = new $wnd.Dygraph.GVizChart(element);
961 chart.draw(dataTable,
962 {
963 valueRange: [minY, maxY]
964 });
965 return chart;
966 }-*/;
967</pre>
968
68f9bed3 969 <h2 id="policy">Data Policy</h2>
15c966e0 970 <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>
2739bb8f 971
68f9bed3 972 <p style="font-size:0.8em">Created May 9, 2008 by <a href=mailto:danvdk@gmail.com>Dan Vanderkam</a></p>
15c966e0 973 </div>
fe57a69b 974
a9df40de 975
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976 <!-- Google Analytics -->
977 <script src="http://www.google-analytics.com/urchin.js" type="text/javascript"></script>
978 <script type="text/javascript">_uacct = "UA-769809-1";urchinTracker();</script>
078d1d29 979</body>
65914f5f 980</html>