# dim_reduction Package¶

## dimensionality_reduction Module¶

Created on Sep 28, 2012

class composes.transformation.dim_reduction.dimensionality_reduction.DimensionalityReduction(reduced_dimension)

Bases: object

classdocs

create_operation()
get_name()
get_reduced_dimension()
name
reduced_dimension

## nmf Module¶

Created on Oct 1, 2012

class composes.transformation.dim_reduction.nmf.Nmf(reduced_dimension)

Performs Non-negative Matrix Factorization to reduced dimension $$k$$.

Given an input non-negative matrix $$X$$, it computes the decomposition:

$$X \approx WH$$ where W and H are non-negative matrices which minimize $$||X-WH||_{2}$$

It returns the matrix W.

apply(matrix_)
nndsvd_init(matrix_)
random_init(matrix_)
v_col_init(matrix_)

## svd Module¶

Created on Sep 28, 2012

Performs truncated Singular Value Decomposition to a reduced dimension $$k$$.
Given an input matrix $$X$$, it computes the decomposition:
$$X = U \Sigma V^{T}$$
It returns $$U \Sigma$$ truncated to dimension $$min(k,rank(X))$$