Linear classifier builder using a logit loss function. More...

#include <clsfy_binary_hyperplane_logit_builder.h>

Inheritance diagram for clsfy_binary_hyperplane_logit_builder:

Public Member Functions
	clsfy_binary_hyperplane_logit_builder ()
void	set_alpha (double a)
	Weighting on regularisation term.
void	set_min_p (double p)
	Min prob to be returned by classifier.
double	build (clsfy_classifier_base &classifier, mbl_data_wrapper< vnl_vector< double > > &inputs, const vcl_vector< unsigned > &outputs) const
	Build a linear classifier, with the given data.
virtual double	build (clsfy_classifier_base &model, mbl_data_wrapper< vnl_vector< double > > &inputs, unsigned nClasses, const vcl_vector< unsigned > &outputs) const
	Build model from data.
short	version_no () const
	Version number for I/O.
vcl_string	is_a () const
	Name of the class.
virtual bool	is_class (vcl_string const &s) const
	Name of the class.
void	print_summary (vcl_ostream &os) const
	Print class to os.
virtual clsfy_builder_base *	clone () const
	Create a deep copy.
virtual void	b_write (vsl_b_ostream &) const
	Save class to binary file stream.
virtual void	b_read (vsl_b_istream &)
	Load class from binary file stream.
virtual clsfy_classifier_base *	new_classifier () const
	Create a new untrained linear classifier with binary output.
virtual void	config (vcl_istream &as)
	Initialise the parameters from a text stream.
Static Public Member Functions
static vcl_auto_ptr < clsfy_builder_base >	new_builder (vcl_istream &as)
	Load description from a text stream.
Private Attributes
double	alpha_
	Weighting on regularisation term.
double	min_p_
	Min prob to be returned by classifier.

Detailed Description

Linear classifier builder using a logit loss function.

Finds hyperplane and bias to minimise a cost function which minimises the sum of log(pr(error)), ie

alpha*|w|^2 - sum log[(1-minp)logit(c_i * (b+w.x_i)) + minp]

Where c_i is +/-1, x_i is the training vector and minp is a lower bound on output probability. This focuses attention on points near boundary.

Definition at line 27 of file clsfy_binary_hyperplane_logit_builder.h.

Constructor & Destructor Documentation

clsfy_binary_hyperplane_logit_builder::clsfy_binary_hyperplane_logit_builder ( )

Definition at line 22 of file clsfy_binary_hyperplane_logit_builder.cxx.

Member Function Documentation

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

Load class from binary file stream.

Reimplemented from clsfy_binary_hyperplane_ls_builder.

Definition at line 117 of file clsfy_binary_hyperplane_logit_builder.cxx.

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

Save class to binary file stream.

Reimplemented from clsfy_binary_hyperplane_ls_builder.

Definition at line 106 of file clsfy_binary_hyperplane_logit_builder.cxx.

double clsfy_binary_hyperplane_logit_builder::build	(	clsfy_classifier_base &	classifier,
		mbl_data_wrapper< vnl_vector< double > > &	inputs,
		const vcl_vector< unsigned > &	outputs
	)		const

Build a linear classifier, with the given data.

Build a linear hyperplane classifier with the given data.

Return the mean error over the training set. Builds by minimising clsfy_logit_loss_function() with given inputs, and a regularisation term using clsfy_quad_regulariser

Reimplemented from clsfy_binary_hyperplane_ls_builder.

Definition at line 55 of file clsfy_binary_hyperplane_logit_builder.cxx.

double clsfy_binary_hyperplane_logit_builder::build	(	clsfy_classifier_base &	classifier,
		mbl_data_wrapper< vnl_vector< double > > &	inputs,
		unsigned	n_classes,
		const vcl_vector< unsigned > &	outputs
	)		const `[virtual]`

Build model from data.

Build a linear classifier, with the given data.

Return the mean error over the training set. For this classifiers, you must nClasses==1 to indicate a binary classifier

Return the mean error over the training set. n_classes must be 1.

Reimplemented from clsfy_binary_hyperplane_ls_builder.

Definition at line 45 of file clsfy_binary_hyperplane_logit_builder.cxx.

clsfy_builder_base * clsfy_binary_hyperplane_logit_builder::clone ( ) const [virtual]

Create a deep copy.

client is responsible for deleting returned object.

Reimplemented from clsfy_binary_hyperplane_ls_builder.

Definition at line 166 of file clsfy_binary_hyperplane_logit_builder.cxx.

void clsfy_builder_base::config ( vcl_istream & as ) [virtual, inherited]

Initialise the parameters from a text stream.

Default case accepts no parameters.

Reimplemented in clsfy_rbf_svm_smo_1_builder, clsfy_parzen_builder, clsfy_knn_builder, clsfy_null_builder, and clsfy_binary_1d_wrapper_builder.

Definition at line 26 of file clsfy_builder_base.cxx.

vcl_string clsfy_binary_hyperplane_logit_builder::is_a ( ) const [virtual]

Name of the class.

Reimplemented from clsfy_binary_hyperplane_ls_builder.

Definition at line 139 of file clsfy_binary_hyperplane_logit_builder.cxx.

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

Name of the class.

Reimplemented from clsfy_binary_hyperplane_ls_builder.

Definition at line 146 of file clsfy_binary_hyperplane_logit_builder.cxx.

vcl_auto_ptr< clsfy_builder_base > clsfy_builder_base::new_builder ( vcl_istream & as ) [static, inherited]

Load description from a text stream.

The stream should contain the name of the feature extractor class that will be used, followed by a brace-enclosed list of parameters for the builder. This function will construct the appropriate clsfy_builder_base derivative and return that.

Exceptions: