Uses the EM algorithm to build vpdfl_mixture objects. More...

#include <vpdfl_mixture_builder.h>

Inheritance diagram for vpdfl_mixture_builder:

Public Member Functions
	vpdfl_mixture_builder ()
	Dflt ctor.
	vpdfl_mixture_builder (const vpdfl_mixture_builder &)
	Copy ctor.
vpdfl_mixture_builder &	operator= (const vpdfl_mixture_builder &)
	Copy operator.
virtual	~vpdfl_mixture_builder ()
	Destructor.
void	init (const vpdfl_builder_base &builder, int n)
	Initialise n builders of type builder.
bool	weights_fixed () const
	Whether weights on components left unchanged during iterations.
void	set_weights_fixed (bool b)
	Whether weights on components left unchanged during iterations.
void	set_max_iterations (int n)
	Define maximum number of EM iterations allowed.
int	max_iterations () const
	Define maximum number of EM iterations allowed.
unsigned	n_builders () const
	Number of basis builders.
vpdfl_builder_base &	builder (unsigned i)
	Return i-th builder.
virtual vpdfl_pdf_base *	new_model () const
	Create empty model.
virtual void	set_min_var (double min_var)
	Define lower threshold on variance for built models.
virtual double	min_var () const
	Get lower threshold on variance for built models.
virtual void	build (vpdfl_pdf_base &model, const vnl_vector< double > &mean) const
	Build default model with given mean.
virtual void	build (vpdfl_pdf_base &model, mbl_data_wrapper< vnl_vector< double > > &data) const
	Build model from data.
virtual void	weighted_build (vpdfl_pdf_base &model, mbl_data_wrapper< vnl_vector< double > > &data, const vcl_vector< double > &wts) const
	Build model from weighted data.
void	preset_initial_means (const vcl_vector< vnl_vector< double > > &component_means)
	Preset initial component means.
short	version_no () const
	Version number for I/O.
virtual vcl_string	is_a () const
	Name of the class.
virtual bool	is_class (vcl_string const &s) const
	Does the name of the class match the argument?.
virtual vpdfl_builder_base *	clone () const
	Create a copy on the heap and return base class pointer.
virtual void	print_summary (vcl_ostream &os) const
	Print class to os.
virtual void	b_write (vsl_b_ostream &bfs) const
	Save class to binary file stream.
virtual void	b_read (vsl_b_istream &bfs)
	Load class from binary file stream.
virtual void	config_from_stream (vcl_istream &is)
	Read initialisation settings from a stream.
Static Public Member Functions
static void	calc_mean_and_variance (vpdfl_mixture &model)
	Calculate and set the mixture's mean and variance.
static vcl_auto_ptr < vpdfl_builder_base >	new_builder_from_stream (vcl_istream &is)
	Create a vpdfl_builder_base object given a config stream.
static vcl_auto_ptr < vpdfl_builder_base >	new_pdf_builder_from_stream (vcl_istream &)
	Create a vpdfl_builder_base object given a config stream (recursive style).
Private Member Functions
void	initialise_given_means (vpdfl_mixture &model, const vnl_vector< double > *data, const vcl_vector< vnl_vector< double > > &mean, const vcl_vector< double > &wts) const
	Assumes means set up. Estimates starting components.
void	initialise_to_regular_samples (vpdfl_mixture &model, const vnl_vector< double > *data, const vcl_vector< double > &wts) const
	Means centred on data[i*f].
void	initialise_diagonal (vpdfl_mixture &model, const vnl_vector< double > *data, const vcl_vector< double > &wts) const
	Select positions along diagonal of bounding box.
void	initialise (vpdfl_mixture &model, const vnl_vector< double > *data, const vcl_vector< double > &wts) const
	Select positions and widths for components to start.
void	e_step (vpdfl_mixture &model, vcl_vector< vnl_vector< double > > &probs, const vnl_vector< double > *data, const vcl_vector< double > &wts) const
	The Expectation part of the EM algorithm.
double	m_step (vpdfl_mixture &model, const vcl_vector< vnl_vector< double > > &probs, const vnl_vector< double > *data, const vcl_vector< double > &wts) const
	The Maximisation part of the EM algorithm.
void	init ()
void	delete_stuff ()
Private Attributes
vcl_vector< vpdfl_builder_base * >	builder_
double	min_var_
int	max_its_
vcl_vector< vnl_vector< double > >	initial_means_
bool	weights_fixed_
	Whether weights changed during iterations.

Detailed Description

Uses the EM algorithm to build vpdfl_mixture objects.

Definition at line 28 of file vpdfl_mixture_builder.h.

Constructor & Destructor Documentation

vpdfl_mixture_builder::vpdfl_mixture_builder ( )

Dflt ctor.

Definition at line 50 of file vpdfl_mixture_builder.cxx.

vpdfl_mixture_builder::vpdfl_mixture_builder ( const vpdfl_mixture_builder & b )

Copy ctor.

Definition at line 57 of file vpdfl_mixture_builder.cxx.

vpdfl_mixture_builder::~vpdfl_mixture_builder ( ) [virtual]

Destructor.

Definition at line 96 of file vpdfl_mixture_builder.cxx.

Member Function Documentation

void vpdfl_mixture_builder::b_read ( vsl_b_istream & bfs ) [virtual]

Load class from binary file stream.

Implements vpdfl_builder_base.

Definition at line 596 of file vpdfl_mixture_builder.cxx.

void vpdfl_mixture_builder::b_write ( vsl_b_ostream & bfs ) const [virtual]

Save class to binary file stream.

Implements vpdfl_builder_base.

Definition at line 585 of file vpdfl_mixture_builder.cxx.

void vpdfl_mixture_builder::build	(	vpdfl_pdf_base &	model,
		const vnl_vector< double > &	mean
	)		const `[virtual]`

Build default model with given mean.

Implements vpdfl_builder_base.

Definition at line 153 of file vpdfl_mixture_builder.cxx.

void vpdfl_mixture_builder::build	(	vpdfl_pdf_base &	model,
		mbl_data_wrapper< vnl_vector< double > > &	data
	)		const `[virtual]`

Build model from data.

Use EM algorithm to best fit mixture model to given data If model does not have the correct number of components they will be initialised to means scattered through the data. If they model has the correct number of components it is assumed that they have been set to sensible initial values. The EM algorithm will be used to optimise their parameters.

Implements vpdfl_builder_base.

Definition at line 163 of file vpdfl_mixture_builder.cxx.

vpdfl_builder_base& vpdfl_mixture_builder::builder ( unsigned i ) [inline]

Return i-th builder.

Definition at line 109 of file vpdfl_mixture_builder.h.

void vpdfl_mixture_builder::calc_mean_and_variance ( vpdfl_mixture & model ) [static]

Calculate and set the mixture's mean and variance.

This should be used after the weights or components of the model have been altered.

Definition at line 522 of file vpdfl_mixture_builder.cxx.

vpdfl_builder_base * vpdfl_mixture_builder::clone ( ) const [virtual]

Create a copy on the heap and return base class pointer.

Implements vpdfl_builder_base.

Definition at line 564 of file vpdfl_mixture_builder.cxx.

void vpdfl_mixture_builder::config_from_stream ( vcl_istream & is ) [virtual]

Read initialisation settings from a stream.

Parameters:

   {
     min_var: 1.0e-6
     // Number of pdf bases to use
     n_pdfs: 3
     // Type of basis pdf
     basis_pdf: axis_gaussian { min_var: 0.0001 }
     // Maximum number of iterations
     max_its: 10
     // When true, fix weights during EM
     weights_fixed: false
   }

Exceptions:

mbl_exception_parse_error if the parse fails.

Parameters:

   {
     min_var: 1.0e-6
     n_pdfs: 3
     // Type of basis pdf
     basis_pdf: axis_gaussian { min_var: 0.0001 }
   }

Exceptions:

mbl_exception_parse_error if the parse fails.

Reimplemented from vpdfl_builder_base.

Definition at line 640 of file vpdfl_mixture_builder.cxx.

void vpdfl_mixture_builder::delete_stuff ( ) [private]

Definition at line 87 of file vpdfl_mixture_builder.cxx.

void vpdfl_mixture_builder::e_step	(	vpdfl_mixture &	model,
		vcl_vector< vnl_vector< double > > &	probs,
		const vnl_vector< double > *	data,
		const vcl_vector< double > &	wts
	)		const `[private]`

The Expectation part of the EM algorithm.

Definition at line 365 of file vpdfl_mixture_builder.cxx.

void vpdfl_mixture_builder::init ( ) [private]

Definition at line 40 of file vpdfl_mixture_builder.cxx.

void vpdfl_mixture_builder::init	(	const vpdfl_builder_base &	builder,
		int	n
	)

Initialise n builders of type builder.

Clone taken of builder

Definition at line 105 of file vpdfl_mixture_builder.cxx.

void vpdfl_mixture_builder::initialise	(	vpdfl_mixture &	model,
		const vnl_vector< double > *	data,
		const vcl_vector< double > &	wts
	)		const `[private]`

Select positions and widths for components to start.

Definition at line 344 of file vpdfl_mixture_builder.cxx.

void vpdfl_mixture_builder::initialise_diagonal	(	vpdfl_mixture &	model,
		const vnl_vector< double > *	data,
		const vcl_vector< double > &	wts
	)		const `[private]`

Select positions along diagonal of bounding box.

Definition at line 291 of file vpdfl_mixture_builder.cxx.

void vpdfl_mixture_builder::initialise_given_means	(	vpdfl_mixture &	model,
		const vnl_vector< double > *	data,
		const vcl_vector< vnl_vector< double > > &	mean,
		const vcl_vector< double > &	wts
	)		const `[private]`

Assumes means set up. Estimates starting components.

Parameters:

mean_sep : Rough guess of mean separation between points

Definition at line 247 of file vpdfl_mixture_builder.cxx.

void vpdfl_mixture_builder::initialise_to_regular_samples	(	vpdfl_mixture &	model,
		const vnl_vector< double > *	data,
		const vcl_vector< double > &	wts
	)		const `[private]`

Means centred on data[i*f].

Definition at line 322 of file vpdfl_mixture_builder.cxx.

vcl_string vpdfl_mixture_builder::is_a ( ) const [virtual]

Name of the class.

Reimplemented from vpdfl_builder_base.

Definition at line 543 of file vpdfl_mixture_builder.cxx.

bool vpdfl_mixture_builder::is_class ( vcl_string const & s ) const [virtual]

Does the name of the class match the argument?.

Reimplemented from vpdfl_builder_base.

Definition at line 550 of file vpdfl_mixture_builder.cxx.

double vpdfl_mixture_builder::m_step	(	vpdfl_mixture &	model,
		const vcl_vector< vnl_vector< double > > &	probs,
		const vnl_vector< double > *	data,
		const vcl_vector< double > &	wts
	)		const `[private]`

The Maximisation part of the EM algorithm.

Definition at line 430 of file vpdfl_mixture_builder.cxx.

int vpdfl_mixture_builder::max_iterations ( ) const [inline]

Define maximum number of EM iterations allowed.

Definition at line 103 of file vpdfl_mixture_builder.h.

double vpdfl_mixture_builder::min_var ( ) const [virtual]

Get lower threshold on variance for built models.

Implements vpdfl_builder_base.

Definition at line 145 of file vpdfl_mixture_builder.cxx.

unsigned vpdfl_mixture_builder::n_builders ( ) const [inline]

Number of basis builders.

Definition at line 106 of file vpdfl_mixture_builder.h.

vcl_auto_ptr< vpdfl_builder_base > vpdfl_builder_base::new_builder_from_stream ( vcl_istream & is ) [static, inherited]

Create a vpdfl_builder_base object given a config stream.

Exceptions:

mbl_exception	if parse error.
vcl_runtime_exception	if parse error.

This will store the constructed builder.

Incoming properties.

Definition at line 55 of file vpdfl_builder_base.cxx.

vpdfl_pdf_base * vpdfl_mixture_builder::new_model ( ) const [virtual]

Create empty model.

Implements vpdfl_builder_base.

Definition at line 129 of file vpdfl_mixture_builder.cxx.

vcl_auto_ptr< vpdfl_builder_base > vpdfl_builder_base::new_pdf_builder_from_stream ( vcl_istream & is ) [static, inherited]

Create a vpdfl_builder_base object given a config stream (recursive style).

Creates object, then uses config_from_stream(is) to set up internals

Exceptions:

vcl_runtime_exception if parse error.

Creates object, then uses config_from_stream(is) to set up internals

Definition at line 145 of file vpdfl_builder_base.cxx.

vpdfl_mixture_builder & vpdfl_mixture_builder::operator= ( const vpdfl_mixture_builder & b )

Copy operator.

Definition at line 66 of file vpdfl_mixture_builder.cxx.

void vpdfl_mixture_builder::preset_initial_means ( const vcl_vector< vnl_vector< double > > & component_means )

Preset initial component means.

When initialise is called these means will be used as the initial guess Note that the vector must is copied

Definition at line 359 of file vpdfl_mixture_builder.cxx.

void vpdfl_mixture_builder::print_summary ( vcl_ostream & os ) const [virtual]

Print class to os.

Implements vpdfl_builder_base.

Definition at line 571 of file vpdfl_mixture_builder.cxx.

void vpdfl_mixture_builder::set_max_iterations ( int n )

Define maximum number of EM iterations allowed.

Definition at line 116 of file vpdfl_mixture_builder.cxx.

void vpdfl_mixture_builder::set_min_var ( double min_var ) [virtual]

Define lower threshold on variance for built models.

Implements vpdfl_builder_base.

Definition at line 137 of file vpdfl_mixture_builder.cxx.

void vpdfl_mixture_builder::set_weights_fixed ( bool b )

Whether weights on components left unchanged during iterations.

Define whether weights on components can change or not.

Definition at line 121 of file vpdfl_mixture_builder.cxx.

short vpdfl_mixture_builder::version_no ( ) const

Version number for I/O.

Reimplemented from vpdfl_builder_base.

Definition at line 557 of file vpdfl_mixture_builder.cxx.

void vpdfl_mixture_builder::weighted_build	(	vpdfl_pdf_base &	model,
		mbl_data_wrapper< vnl_vector< double > > &	data,
		const vcl_vector< double > &	wts
	)		const `[virtual]`

Build model from weighted data.

Use EM algorithm to best fit mixture model to given data If model does not have the correct number of components they will be initialised to means scattered through the data. If they model has the correct number of components it is assumed that they have been set to sensible initial values. The EM algorithm will be used to optimise their parameters.

Implements vpdfl_builder_base.

Definition at line 173 of file vpdfl_mixture_builder.cxx.

bool vpdfl_mixture_builder::weights_fixed ( ) const [inline]

Whether weights on components left unchanged during iterations.

Definition at line 94 of file vpdfl_mixture_builder.h.