Introduction

LIBSVM is an integrated software for support vector classification, (C-SVC, nu-SVC), regression (epsilon-SVR, nu-SVR) and distribution estimation (one-class SVM). It supports multi-class classification.

Since version 2.8, it implements an SMO-type algorithm proposed in this paper:
R.-E. Fan, P.-H. Chen, and C.-J. Lin. Working set selection using second order information for training SVM. Journal of Machine Learning Research 6, 1889-1918, 2005. You can also find a pseudo code there. (how to cite LIBSVM)

Our goal is to help users from other fields to easily use SVM as a tool. LIBSVM provides a simple interface where users can easily link it with their own programs. Main features of LIBSVM include

• Different SVM formulations

• Efficient multi-class classification

• Cross validation for model selection

• Probability estimates

• Various kernels (including precomputed kernel matrix)

• Weighted SVM for unbalanced data

• Both C++ and Java sources

• GUI demonstrating SVM classification and regression

• Python, R, MATLAB, Perl, Ruby, Weka, Common LISP, CLISP, Haskell, OCaml, LabVIEW, and PHP interfaces. C# .NET code and CUDA extension is available.
  It's also included in some data mining environments: RapidMiner, PCP, and LIONsolver.

• Automatic model selection which can generate contour of cross validation accuracy.