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About |
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----- |
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Flot is a Javascript plotting library for jQuery. Read more at the |
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website: |
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http://code.google.com/p/flot/ |
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Take a look at the examples linked from above, they should give a good |
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impression of what Flot can do and the source code of the examples is |
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probably the fastest way to learn how to use Flot. |
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Installation |
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------------ |
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Just include the Javascript file after you've included jQuery. |
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Generally, all browsers that support the HTML5 canvas tag are |
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supported. |
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For support for Internet Explorer < 9, you can use Excanvas, a canvas |
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emulator; this is used in the examples bundled with Flot. You just |
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include the excanvas script like this: |
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<!--[if lte IE 8]><script language="javascript" type="text/javascript" src="excanvas.min.js"></script><![endif]--> |
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If it's not working on your development IE 6.0, check that it has |
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support for VML which Excanvas is relying on. It appears that some |
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stripped down versions used for test environments on virtual machines |
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lack the VML support. |
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You can also try using Flashcanvas (see |
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http://code.google.com/p/flashcanvas/), which uses Flash to do the |
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emulation. Although Flash can be a bit slower to load than VML, if |
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you've got a lot of points, the Flash version can be much faster |
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overall. Flot contains some wrapper code for activating Excanvas which |
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Flashcanvas is compatible with. |
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You need at least jQuery 1.2.6, but try at least 1.3.2 for interactive |
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charts because of performance improvements in event handling. |
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Basic usage |
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----------- |
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Create a placeholder div to put the graph in: |
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<div id="placeholder"></div> |
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You need to set the width and height of this div, otherwise the plot |
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library doesn't know how to scale the graph. You can do it inline like |
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this: |
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<div id="placeholder" style="width:600px;height:300px"></div> |
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You can also do it with an external stylesheet. Make sure that the |
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placeholder isn't within something with a display:none CSS property - |
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in that case, Flot has trouble measuring label dimensions which |
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results in garbled looks and might have trouble measuring the |
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placeholder dimensions which is fatal (it'll throw an exception). |
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Then when the div is ready in the DOM, which is usually on document |
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ready, run the plot function: |
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$.plot($("#placeholder"), data, options); |
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Here, data is an array of data series and options is an object with |
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settings if you want to customize the plot. Take a look at the |
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examples for some ideas of what to put in or look at the reference |
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in the file "API.txt". Here's a quick example that'll draw a line from |
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(0, 0) to (1, 1): |
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$.plot($("#placeholder"), [ [[0, 0], [1, 1]] ], { yaxis: { max: 1 } }); |
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The plot function immediately draws the chart and then returns a plot |
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object with a couple of methods. |
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What's with the name? |
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--------------------- |
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First: it's pronounced with a short o, like "plot". Not like "flawed". |
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So "Flot" rhymes with "plot". |
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And if you look up "flot" in a Danish-to-English dictionary, some up |
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the words that come up are "good-looking", "attractive", "stylish", |
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"smart", "impressive", "extravagant". One of the main goals with Flot |
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is pretty looks. |
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