jStat - JavaScript Statistical Library
jStat provides native javascript implementations of statistical functions. Full details are available in the docs. jStat provides more functions than most libraries, including the weibull, cauchy, poisson, hypergeometric, and beta distributions. For most distributions, jStat provides the pdf, cdf, inverse, mean, mode, variance, and a sample function, allowing for more complex calculations.
Using jStat in a Browser
jStat can be used in the browser. The jStat
object will be added to the window. For example:
<script src="components/jstat.js"></script> <!-- include jStat, from the CDN or otherwise -->
<script>
...
var jstat = this.jStat(dataset); // jStat will be added to the window
...
data[i]['cum'] = jstat.normal(jstat.mean(), jstat.stdev()).cdf(data[i].x);
...
</script>
CDN
The library is hosted on jsDelivr using the follwing url:
//cdn.jsdelivr.net/jstat/latest/jstat.min.js
Note that 'latest'
can be replaced with any released verion of jStat.
Module Loaders
Currently jStat is exposed as j$
and jStat
inside an object, rather than
exported directly. This may confuse some module loaders, however should be
easily remedied with the correct configuration.
NodeJS & NPM
To install via npm:
npm install --save jStat
When loading under Node be sure to reference the child object.
var jStat = require('jStat').jStat;
RequireJS Shim
For RequireJS not only exports
but also init
function must be specified.
requirejs.config({
paths: {
'jstat': 'path/to/jstat/dist/jstat.min'
},
shim: {
jstat: {
exports: ['j$', 'jStat'],
init: function () {
return {
j$: j$,
jStat: jStat
};
}
}
}
});
Build Prerequisites
In order to build jStat, you need to have GNU make 3.8 or later, Node.js 0.2 or later, and git 1.7 or later. (Earlier versions might work OK, but are not tested.)
Windows users have two options:
- Install msysgit (Full installer for official Git), GNU make for Windows, and a binary version of Node.js. Make sure all three packages are installed to the same location (by default, this is C:\Program Files\Git).
- Install Cygwin (make sure you install the git, make, and which packages), then either follow the Node.js build instructions or install the binary version of Node.js.
Mac OS users should install Xcode (comes on your Mac OS install DVD, or downloadable from
Apple's Xcode site) and
http://mxcl.github.com/homebrew/. Once Homebrew is installed, run brew install git
to install git,
and brew install node
to install Node.js.
Linux/BSD users should use their appropriate package managers to install make, git, and node, or build from source if you swing that way.
Building jStat
First, clone a copy of the jStat git repo by running git clone git://github.com/jstat/jstat.git
.
To download all necessary libraries run npm install
.
Then, to get a complete, minified version of jStat and all documentation, simply cd
to the jstat
directory and
type make
. If you don't have Node installed and/or want to make a basic, uncompressed, unlinted version of jstat,
use make jstat
instead of make
.
The built version of jStat will be put in the dist/
subdirectory.
Generate just the documentation by running make doc
. Documentation will be placed in dist/docs
by default.
To remove all built files, run make clean
.
Running Tests
Execute all tests by running make test
.
Or if you wish to run a specific test, cd
to test/<subdir>
and run node <some_test>-test.js
.
Get the Code
Both the minified and unminified source are located in the dist/
directory. For those who don't want to build
it themselves.
Contribute
jStat is now going to follow most of the v8 JavaScript guidelines. There will be plenty of source that uses the old style, but we're going to work away from that.
Also, we'll be going through and reimplementing a good portion of the code to run faster. Hopefully it won't take too long to get the project on one basic standard.
When submitting pull requests, no need to check in dist/*.js. They'll be recompiled for distribution anyway.
Join the Community
We always like discussion of how to improve jStat. Join us at our mailing list and let us know what you'd like to see. Also come ask questions in the #jstat channel on irc.freenode.net.