Interfacing with other libraries

MDP is, of course, not the only Python library to offer an implementation of signal processing and machine learning methods. Several other projects, often specialized in different algorithms, or based on different approaches, are being developed in parallel. In order to avoid an excessive duplication of efforts, the long-term philosophy of MDP is that of automatically wrapping the algorithms defined in external libraries, if these are installed. In this way, MDP users have access to a larger number of algorithms, and at the same time,we offer the MDP infrastructure (flows, caching, etc.) to users of the wrapped libraries.

At present, MDP automatically creates wrapper nodes for the following libraries if they are installed:

• Shogun (http://www.shogun-toolbox.org/): The Shogun machine learning toolbox provides a large set of different support vector machine implementations and classifiers. Each of them can be combined with another large set of kernels.

  The MDP wrapper simplifies setting the parameters for the kernels and classifiers, and provides reasonable default values. In order to avoid conflicts, users are encouraged to keep an eye on the original C++ API and provide as many parameters as specified.

• libsvm (http://www.csie.ntu.edu.tw/~cjlin/libsvm/): libsvm is a library for support vector machines. Even though there is also a libsvm wrapper in the Shogun toolbox, the direct libsvm interface is simpler to use and it provides estimates of the probability of different labels.

  Note that starting with MDP 3.0 we only support the Python API for the recent libsvm versions 2.91 and 3.0.

• scikits.learn (http://scikit-learn.sourceforge.net/index.html): scikits.learn is a collection of efficient machine learning algorithms. We offer automatic wrappers to all algorithms defined by in the library scikits.learn, and there are a lot of them! The wrapped algorithms can be recognised as their name end with ScikitsLearnNode.

  All ScikitsLearnNode contain an instance of the wrapped scikits.learn instance in the attribute scikits_alg, and allow setting all the parameters using the original keywords. You can see the scikits.learn wrapper in action in this example application that uses scikits.learn to perform handwritten digits recognition.

  As of MDP 3.0, the wrappers must be considered experimental, because there are still a few inconsistencies in the scikits.learn interface that we need to address.