Table of Contents

Class: MixtureOfGaussians compClust/mlx/models/MixtureOfGaussians.py
Base Classes   
IModel
Methods   
__init__
__pdf
__repr__
classify1
classify2
evaluateFitness
getDiagLogLikelihood
getLogLikelihood
setParameters
  __init__ 
__init__ (
        self,
        k,
        means,
        covariances,
        weights=None,
        )

Creates a new Mixture of Gaussians (MoG) Model, containing k Gaussian clusters in d-dimensional space.

Where:

  • means is a k-by-d matrix containing the means (one per row) of the k-Gaussian models.

  • covariances is a set of k d-by-d covariance matrices (i.e. a k-by-d-by-d matrix) containing the covariances of the k-Gaussian models.

  • weights is a 1-by-k matrix of weights, one for each model. Optional. If not specified, each of the k-Guassian models will have equal weight. That is, each element of weights will default to 1 / k.

  __pdf 
__pdf (
        self,
        x,
        m,
        c,
        )

  __repr__ 
__repr__ ( self )

  classify1 
classify1 ( self,  data )

  classify2 
classify2 ( self,  data )

  evaluateFitness 
evaluateFitness ( self,  data )

Return the fitness of the model given a paricular set of data.

First attempt to generate the full covariance fitness score, if that fails, try to generate a diagonal covariance, if that fails, then the log-likelihood is set to -MAX_FLOAT =~ -1e38.

  getDiagLogLikelihood 
getDiagLogLikelihood ( self,  data )

Returns the log-likelihood of the given data under the current model using a diagonal covariance matrix. Data is a matrix of numbers whose dimensionality (number of columns) must agree with that of the model.

Exceptions   
ValueError, "Data matrix must have d=%d columns." %( self.d )
  getLogLikelihood 
getLogLikelihood ( self,  data )

Returns the log-likelihood of the given data under the current model. Data is a matrix of numbers whose dimensionality (number of columns) must agree with that of the model.

Exceptions   
ValueError, "Data matrix must have d=%d columns." %( self.d )
  setParameters 
setParameters (
        self,
        k,
        means,
        covariances,
        weights,
        )

Sets the parameters for this model. See class constructor documentation for more information.

Exceptions   
ValueError, "Covariance matrices are not square."
ValueError, "Means and covariance matrix number of columns do not match."
ValueError, "Means matrix must have k=%d rows." %( k )
ValueError, "There must be k=%d covariance matrices." %( k )
ValueError, "Weights matrix must have k=%d columns." %( k )

Table of Contents

This document was automatically generated on Wed Aug 27 14:25:03 2003 by HappyDoc version 2.1