metric-learn

Metric Learning algorithms in Python.

Algorithms

Large Margin Nearest Neighbor (LMNN)
Information Theoretic Metric Learning (ITML)
Sparse Determinant Metric Learning (SDML)
Least Squares Metric Learning (LSML)
Neighborhood Components Analysis (NCA)

Dependencies

Python 2.6+
numpy, scipy, scikit-learn
(for running the examples only: matplotlib)

Installation/Setup

Run python setup.py install for default installation.

Run python setup.py test to run all tests.

Usage

For full usage examples, see the test and examples directories.

Each metric is a subclass of BaseMetricLearner, which provides default implementations for the methods metric, transformer, and transform. Subclasses must provide an implementation for either metric or transformer.

For an instance of a metric learner named foo learning from a set of d-dimensional points, foo.metric() returns a d by d matrix M such that a distance between vectors x and y is expressed (x-y).dot(M).dot(x-y).

In the same scenario, foo.transformer() returns a d by d matrix L such that a vector x can be represented in the learned space as the vector L.dot(x).

For convenience, the function foo.transform(X) is provided for converting a matrix of points (X) into the learned space, in which standard Euclidean distance can be used.

Notes

If a recent version of the Shogun Python modular (modshogun) library is available, the LMNN implementation will use the fast C++ version from there. The two implementations differ slightly, and the C++ version is more complete.

TODO

implement the rest of the methods on this site

File	Mode	Size
examples
metric_learn
test
.gitignore	-rw-r--r--	30 bytes
.travis.yml	-rw-r--r--	740 bytes
LICENSE.txt	-rw-r--r--	1.0 KB
README.rst	-rw-r--r--	2.1 KB
setup.cfg	-rw-r--r--	70 bytes
setup.py	-rwxr-xr-x	1.1 KB

README.rst