# rb-libsvm -- Ruby language bindings for LIBSVM

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This package provides a Ruby bindings to the [LIBSVM][] library.  SVM
is a machine learning and classification algorithm, and LIBSVM is a
popular free implementation of it, written by Chih-Chung Chang and
Chih-Jen Lin, of National Taiwan University, Taipei. See the book ["Programming
Collective Intelligence,"](http://books.google.com/books?id=fEsZ3Ey-Hq4C) among others, for a usage example.

Note: There exist two other Ruby bindings for LIBSVM. One is named
"Ruby SVM," and is written by Rudi Cilibrasi. It is hard to find
nowadays. The other, more actively developed one is
[libsvm-ruby-swig][svmrubyswig] by Tom Zeng, which is built using
SWIG.

## Dependencies

None.  LIBSVM is bundled with the project.  Just install and go!

Currently this package includes libsvm version 3.13.

LIBSVM includes a number of command line tools for preprocessing
training data and finding parameters. These tools are not included in
this gem. You should install the original package if you need these.
It is also helpful to consult the Readme of the LIBSVM package for 
reference when configuring the training parameters.

## Installation

    gem install rb-libsvm

## Usage

```ruby
require 'libsvm'

# This library is namespaced.
problem = Libsvm::Problem.new
parameter = Libsvm::SvmParameter.new

parameter.cache_size = 1 # in megabytes

parameter.eps = 0.001
parameter.c = 10

examples = [ [1,0,1], [-1,0,-1] ].map {|ary| Libsvm::Node.features(ary) }
labels = [1, -1]

problem.set_examples(labels, examples)

model = Libsvm::Model.train(problem, parameter)

pred = model.predict(Libsvm::Node.features(1, 1, 1))
puts "Example [1, 1, 1] - Predicted #{pred}"
```

## Author

Written by C. Florian Ebeling.

## Contributors

[Rimas Silkaitis](https://github.com/neovintage)

[Aleksander Pohl](https://github.com/apohllo)

## License

This software can be freely used under the terms of the MIT license,
see file MIT-LICENSE.

This package includes the source of LIBSVM, which is free to use under
the license in the file LIBSVM-LICENSE.

### Posts about using SVMs with Ruby

http://neovintage.blogspot.com/2011/11/text-classification-using-support.html

http://www.igvita.com/2008/01/07/support-vector-machines-svm-in-ruby/

[libsvm]:       http://www.csie.ntu.edu.tw/~cjlin/libsvm/

[svmrubyswig]:  http://github.com/tomz/libsvm-ruby-swig/tree/master