The focus of Shogun is on kernel machines such as support vector machines for regression and classification problems. Shogun also offers a full implementation of Hidden Markov models.
The core of Shogun is written in C++ and offers interfaces for MATLAB, Octave, Python, R, Java, Lua, Ruby and C#.
Shogun has been under active development since 1999. Today there is a vibrant user community all over the world using Shogun as a base for research and education, and contributing to the core package.[citation needed]
Supported algorithms
Currently Shogun supports the following algorithms:
Dimensionality reduction algorithms, such as PCA, Kernel PCA, Locally Linear Embedding, Hessian Locally Linear Embedding, Local Tangent Space Alignment, Linear Local Tangent Space Alignment, Kernel Locally Linear Embedding, Kernel Local Tangent Space Alignment, Multidimensional Scaling, Isomap, Diffusion Maps, Laplacian Eigenmaps
Online learning algorithms such as SGD-QN, Vowpal Wabbit
Clustering algorithms: k-means and GMM
Kernel Ridge Regression, Support Vector Regression
Many different kernels are implemented, ranging from kernels for numerical data (such as gaussian or linear kernels) to kernels on special data (such as strings over certain alphabets). The currently implemented kernels for numeric data include:
linear
gaussian
polynomial
sigmoid kernels
The supported kernels for special data include:
Spectrum
Weighted Degree
Weighted Degree with Shifts
The latter group of kernels allows processing of arbitrary sequences over fixed alphabets such as DNA sequences as well as whole e-mail texts.
Special features
As Shogun was developed with bioinformatics applications in mind it is capable of processing huge datasets consisting of up to 10 million samples. Shogun supports the use of pre-calculated kernels. It is also possible to use a combined kernel i.e. a kernel consisting of a linear combination of arbitrary kernels over different domains. The coefficients or weights of the linear combination can be learned as well. For this purpose Shogun offers a multiple kernel learning functionality.[citation needed]
References
S. Sonnenburg, G. Rätsch, S. Henschel, C. Widmer, J. Behr, A. Zien, F. De Bona, A. Binder, C. Gehl and V. Franc: The SHOGUN Machine Learning Toolbox, Journal of Machine Learning Research, 11:1799−1802, June 11, 2010.
M. Gashler. Waffles: A Machine Learning Toolkit. Journal of Machine Learning Research, 12 (July):2383–2387, 2011.
P. Vincent, Y. Bengio, N. Chapados, and O. Delalleau. Plearn high-performance machine learning library. URL http://plearn.berlios.de/.