From: Leonardo Florez-Valencia Date: Tue, 14 Jun 2016 23:59:55 +0000 (-0500) Subject: ... X-Git-Tag: v0.1~143 X-Git-Url: https://git.creatis.insa-lyon.fr/pubgit/?a=commitdiff_plain;h=b3bb78df1a899c796586df5c0a6eec8c84f9b739;p=cpPlugins.git ... --- diff --git a/appli/examples/extensions/CMakeLists.txt b/appli/examples/extensions/CMakeLists.txt index b39f42c..26f7d50 100644 --- a/appli/examples/extensions/CMakeLists.txt +++ b/appli/examples/extensions/CMakeLists.txt @@ -1,5 +1,6 @@ SET( examples_SOURCES + example_IterativeGaussianModelEstimator example_KalmanVelocity example_ImageSlice ) diff --git a/appli/examples/extensions/example_IterativeGaussianModelEstimator.cxx b/appli/examples/extensions/example_IterativeGaussianModelEstimator.cxx new file mode 100644 index 0000000..b168dcb --- /dev/null +++ b/appli/examples/extensions/example_IterativeGaussianModelEstimator.cxx @@ -0,0 +1,81 @@ +#include +#include +#include +#include + +#include + +// ------------------------------------------------------------------------- +const unsigned int Dim = 1; +typedef double TScalar; +typedef +cpExtensions::Algorithms:: +IterativeGaussianModelEstimator< TScalar, Dim > TEstimator; + +// ------------------------------------------------------------------------- +int main( int argc, char* argv[] ) +{ + if( argc < 4 ) + { + std::cerr << "Usage: " << argv[ 0 ] << " mean std samples" << std::endl; + return( 1 ); + + } // fi + TScalar mean = std::atof( argv[ 1 ] ); + TScalar var = std::atof( argv[ 2 ] ); + unsigned int samples = std::atoi( argv[ 3 ] ); + var *= var; + + // Prepare estimator + TEstimator::Pointer estimator = TEstimator::New( ); + + // Generate numbers + std::random_device r; + std::seed_seq seed{ r( ), r( ), r( ), r( ), r( ), r( ), r( ), r( ) }; + std::mt19937 e( seed ); + std::normal_distribution< > dist( mean, std::sqrt( var ) ); + double local_mean = double( 0 ); + std::vector< double > data; + for( unsigned int s = 0; s < samples; ++s ) + { + double v = dist( e ); + estimator->AddSample( v ); + local_mean += v; + data.push_back( v ); + + } // rof + local_mean /= double( samples ); + + double local_var = double( 0 ); + for( auto d = data.begin( ); d != data.end( ); ++d ) + local_var += ( *d - local_mean ) * ( *d - local_mean ); + local_var /= double( samples - 1 ); + + // Show results + std::cout + << "Mean: " + << mean << " <-> " + << estimator->GetMean( )[ 0 ] << " <-> " + << local_mean + << std::endl; + std::cout + << "Var: " + << var << " <-> " + << estimator->GetCovariance( )[ 0 ][ 0 ] << " <-> " + << estimator->GetUnbiasedCovariance( )[ 0 ][ 0 ] << " <-> " + << local_var + << std::endl; + + std::cout << "--------------------------------------" << std::endl; + for( unsigned int s = 0; s < 15; ++s ) + { + double v = dist( e ); + double d = std::sqrt( estimator->SquaredMahalanobis( v ) ); + std::cout << "Distante to " << v << " is " << d << std::endl; + + } // rof + + return( 0 ); +} + +// eof - $RCSfile$ diff --git a/lib/cpExtensions/Algorithms/IterativeGaussianModelEstimator.h b/lib/cpExtensions/Algorithms/IterativeGaussianModelEstimator.h index 5cf7332..95947cf 100644 --- a/lib/cpExtensions/Algorithms/IterativeGaussianModelEstimator.h +++ b/lib/cpExtensions/Algorithms/IterativeGaussianModelEstimator.h @@ -8,15 +8,22 @@ #include #include #include -#include +#include + +#include +#include +#include +#include namespace cpExtensions { namespace Algorithms { /** + * Recursive formulation taken from: + * http://lmb.informatik.uni-freiburg.de/lectures/mustererkennung/Englische_Folien/07_c_ME_en.pdf */ - template< class S, unsigned int D > + template< class _TScalar, unsigned int _VDimension > class IterativeGaussianModelEstimator : public itk::Object { @@ -26,61 +33,90 @@ namespace cpExtensions typedef itk::SmartPointer< Self > Pointer; typedef itk::SmartPointer< const Self > ConstPointer; - typedef S TScalar; - itkStaticConstMacro( Dimension, unsigned int, D ); + typedef _TScalar TScalar; + itkStaticConstMacro( Dimension, unsigned int, _VDimension ); // Begin concept checking #ifdef ITK_USE_CONCEPT_CHECKING itkConceptMacro( ScalarTypeHasFloatResolution, - ( itk::Concept::IsFloatingPoint< S > ) + ( itk::Concept::IsFloatingPoint< _TScalar > ) ); #endif // End concept checking - typedef vnl_matrix< S > TMatrix; - typedef std::vector< TMatrix > TMatrices; + typedef itk::Matrix< TScalar, Dimension, Dimension > TMatrix; + typedef itk::Vector< TScalar, Dimension > TVector; public: itkNewMacro( Self ); itkTypeMacro( IterativeGaussianModelEstimator, itkObject ); + itkGetConstMacro( Mean, TVector ); + itkGetConstMacro( Covariance, TMatrix ); + itkGetConstMacro( UnbiasedCovariance, TMatrix ); + itkGetConstMacro( NumberOfSamples, unsigned long ); + + itkSetMacro( Mean, TVector ); + itkSetMacro( Covariance, TMatrix ); + itkSetMacro( NumberOfSamples, unsigned long ); + public: - unsigned long GetNumberOfSamples( ) const - { return( ( unsigned long )( this->m_N ) ); } - const TMatrix& GetMu( ) const - { return( this->m_M ); } - const TMatrix& GetOmega( ) const - { return( this->m_O ); } + void Clear( ); + + template< class _TOtherScalar > + void AddSample( const _TOtherScalar& x1, ... ); - void SetNumberOfSamples( unsigned long n ); - void SetMu( const TMatrix& m ); - void SetOmega( const TMatrix& O ); + template< class _TOtherScalar > + void AddSample( const _TOtherScalar* array ); - bool SaveModelToFile( const std::string& filename ) const; - bool LoadModelFromFile( const std::string& filename ); + template< class _TOtherScalar > + void AddSample( const vnl_vector< _TOtherScalar >& v ); - template< class V > - S Probability( const V& sample ) const; + template< class _TOtherScalar > + void AddSample( + const itk::CovariantVector< _TOtherScalar, _VDimension >& v + ); - S Probability( const S& s_x, const S& s_y, ... ) const; + template< class _TOtherScalar > + void AddSample( const itk::Point< _TOtherScalar, _VDimension >& p ); - template< class V, class M > - void GetModel( V& m, M& E ) const; + template< class _TOtherScalar > + void AddSample( const itk::Vector< _TOtherScalar, _VDimension >& v ); - void Clear( ); + template< class _TOtherScalar > + _TScalar SquaredMahalanobis( const _TOtherScalar& x1, ... ) const; + + template< class _TOtherScalar > + _TScalar SquaredMahalanobis( const _TOtherScalar* array ) const; + + template< class _TOtherScalar > + _TScalar SquaredMahalanobis( + const vnl_vector< _TOtherScalar >& v + ) const; + + template< class _TOtherScalar > + _TScalar SquaredMahalanobis( + const itk::CovariantVector< _TOtherScalar, _VDimension >& v + ) const; - template< class V > - void AddSample( const V& sample ); + template< class _TOtherScalar > + _TScalar SquaredMahalanobis( + const itk::Point< _TOtherScalar, _VDimension >& p + ) const; - void AddSample( const S& s_x, const S& s_y, ... ); + template< class _TOtherScalar > + _TScalar SquaredMahalanobis( + const itk::Vector< _TOtherScalar, _VDimension >& v + ) const; protected: IterativeGaussianModelEstimator( ); virtual ~IterativeGaussianModelEstimator( ); protected: - void _UpdateModel( ) const; + void _AddSample( const TVector& v ) const; + _TScalar _SquaredMahalanobis( const TVector& v ) const; private: // Purposely not implemented @@ -88,14 +124,13 @@ namespace cpExtensions void operator=( const Self& other ); protected: - S m_N; - TMatrix m_M; - TMatrix m_O; - - mutable bool m_Updated; - mutable TMatrix m_Cov; - mutable TMatrix m_Inv; - mutable S m_Norm; + // Recursive avg/cov values + mutable unsigned long m_NumberOfSamples; + mutable TVector m_Mean; + mutable TMatrix m_Covariance; + mutable TMatrix m_UnbiasedCovariance; + mutable bool m_InverseUpdated; + mutable TMatrix m_InverseUnbiasedCovariance; }; } // ecapseman diff --git a/lib/cpExtensions/Algorithms/IterativeGaussianModelEstimator.hxx b/lib/cpExtensions/Algorithms/IterativeGaussianModelEstimator.hxx index c6e3cb8..a297c3c 100644 --- a/lib/cpExtensions/Algorithms/IterativeGaussianModelEstimator.hxx +++ b/lib/cpExtensions/Algorithms/IterativeGaussianModelEstimator.hxx @@ -5,239 +5,193 @@ #ifndef __CPEXTENSIONS__ALGORITHMS__ITERATIVEGAUSSIANMODELESTIMATOR__HXX__ #define __CPEXTENSIONS__ALGORITHMS__ITERATIVEGAUSSIANMODELESTIMATOR__HXX__ -#include #include -#include -#include -#include // ------------------------------------------------------------------------- -template< class S, unsigned int D > -void cpExtensions::Algorithms::IterativeGaussianModelEstimator< S, D >:: -SetNumberOfSamples( unsigned long n ) +template< class _TScalar, unsigned int _VDimension > +void cpExtensions::Algorithms:: +IterativeGaussianModelEstimator< _TScalar, _VDimension >:: +Clear( ) { - this->m_N = S( n ); - this->m_Updated = false; - this->Modified( ); + this->m_NumberOfSamples = 0; + this->m_Mean.Fill( TScalar( 0 ) ); + this->m_Covariance.Fill( TScalar( 0 ) ); + this->m_InverseUpdated = false; + this->m_InverseUnbiasedCovariance.Fill( TScalar( 0 ) ); } // ------------------------------------------------------------------------- -template< class S, unsigned int D > -void cpExtensions::Algorithms::IterativeGaussianModelEstimator< S, D >:: -SetMu( const TMatrix& m ) +template< class _TScalar, unsigned int _VDimension > +template< class _TOtherScalar > +void cpExtensions::Algorithms:: +IterativeGaussianModelEstimator< _TScalar, _VDimension >:: +AddSample( const _TOtherScalar& x1, ... ) { - if( m.rows( ) == D && m.columns( ) == 1 ) - { - this->m_M = m; - this->m_Updated = false; - this->Modified( ); - } - else - { - itkExceptionMacro( - << "Input Mu matrix is not a " << D << "x1 matrix" - ); - - } // fi + TVector s; + std::va_list lst; + va_start( lst, x1 ); + s[ 0 ] = TScalar( x1 ); + for( unsigned int d = 1; d < _VDimension; ++d ) + s[ d ] = TScalar( va_arg( lst, double ) ); + va_end( lst ); + this->_AddSample( s ); } // ------------------------------------------------------------------------- -template< class S, unsigned int D > -void cpExtensions::Algorithms::IterativeGaussianModelEstimator< S, D >:: -SetOmega( const TMatrix& O ) +template< class _TScalar, unsigned int _VDimension > +template< class _TOtherScalar > +void cpExtensions::Algorithms:: +IterativeGaussianModelEstimator< _TScalar, _VDimension >:: +AddSample( const _TOtherScalar* array ) { - if( O.rows( ) == D && O.columns( ) == D ) - { - this->m_O = O; - this->m_Updated = false; - this->Modified( ); - } - else - { - itkExceptionMacro( - << "Input Omega matrix is not a " << D << "x" << D << " matrix" - ); - - } // fi + TVector s; + for( unsigned d = 0; d < _VDimension; ++d ) + s[ d ] = TScalar( array[ d ] ); + this->_AddSample( s ); } // ------------------------------------------------------------------------- -template< class S, unsigned int D > -bool cpExtensions::Algorithms::IterativeGaussianModelEstimator< S, D >:: -SaveModelToFile( const std::string& filename ) const +template< class _TScalar, unsigned int _VDimension > +template< class _TOtherScalar > +void cpExtensions::Algorithms:: +IterativeGaussianModelEstimator< _TScalar, _VDimension >:: +AddSample( const vnl_vector< _TOtherScalar >& v ) { - std::ofstream out( filename.c_str( ) ); - if( out ) - { - out << this->m_N << std::endl; - out << this->m_M << std::endl; - out << this->m_O << std::endl; - out.close( ); - return( true ); - } - else - return( false ); + unsigned int len = ( v.size( ) < _VDimension )? v.size: _VDimension; + TVector s; + for( unsigned d = 0; d < len; ++d ) + s[ d ] = TScalar( v[ d ] ); + this->_AddSample( s ); } // ------------------------------------------------------------------------- -template< class S, unsigned int D > -bool cpExtensions::Algorithms::IterativeGaussianModelEstimator< S, D >:: -LoadModelFromFile( const std::string& filename ) +template< class _TScalar, unsigned int _VDimension > +template< class _TOtherScalar > +void cpExtensions::Algorithms:: +IterativeGaussianModelEstimator< _TScalar, _VDimension >:: +AddSample( const itk::CovariantVector< _TOtherScalar, _VDimension >& v ) { - std::ifstream in( filename.c_str( ) ); - if( in ) - { - this->Clear( ); - in >> this->m_N; - for( unsigned int i = 0; i < D; ++i ) - in >> this->m_M[ i ][ 0 ]; - for( unsigned int j = 0; j < D; ++j ) - for( unsigned int i = 0; i < D; ++i ) - in >> this->m_O[ i ][ j ]; - in.close( ); - return( true ); - } - else - return( false ); + TVector s; + for( unsigned d = 0; d < _VDimension; ++d ) + s[ d ] = TScalar( v[ d ] ); + this->_AddSample( s ); } // ------------------------------------------------------------------------- -template< class S, unsigned int D > -template< class V > -S cpExtensions::Algorithms::IterativeGaussianModelEstimator< S, D >:: -Probability( const V& sample ) const +template< class _TScalar, unsigned int _VDimension > +template< class _TOtherScalar > +void cpExtensions::Algorithms:: +IterativeGaussianModelEstimator< _TScalar, _VDimension >:: +AddSample( const itk::Point< _TOtherScalar, _VDimension >& p ) { - if( !this->m_Updated ) - this->_UpdateModel( ); - - TMatrix c( D, 1 ); - for( unsigned int d = 0; d < D; ++d ) - c[ d ][ 0 ] = S( sample[ d ] ) - this->m_M[ d ][ 0 ]; - if( S( 0 ) < this->m_Norm ) - { - // Covariance is NOT null - double v = double( ( c.transpose( ) * ( this->m_Inv * c ) )[ 0 ][ 0 ] ); - v /= double( 2 ); - - return( S( std::exp( -v ) ) ); - } - else - { - // Covariance is null - S n = S( 0 ); - for( unsigned int d = 0; d < D; ++d ) - n += c[ d ][ 0 ] * c[ d ][ 0 ]; - bool equal = ( double( n ) < double( 1e-10 ) ); - return( ( equal )? S( 1 ): S( 0 ) ); - - } // fi + TVector s; + for( unsigned d = 0; d < _VDimension; ++d ) + s[ d ] = TScalar( p[ d ] ); + this->_AddSample( s ); } // ------------------------------------------------------------------------- -template< class S, unsigned int D > -S cpExtensions::Algorithms::IterativeGaussianModelEstimator< S, D >:: -Probability( const S& s_x, const S& s_y, ... ) const +template< class _TScalar, unsigned int _VDimension > +template< class _TOtherScalar > +void cpExtensions::Algorithms:: +IterativeGaussianModelEstimator< _TScalar, _VDimension >:: +AddSample( const itk::Vector< _TOtherScalar, _VDimension >& v ) { - static S sample[ D ]; - - std::va_list args_lst; - va_start( args_lst, s_y ); - sample[ 0 ] = s_x; - sample[ 1 ] = s_y; - for( unsigned int d = 2; d < D; ++d ) - sample[ d ] = S( va_arg( args_lst, double ) ); - va_end( args_lst ); - return( this->Probability( sample ) ); + TVector s; + for( unsigned d = 0; d < _VDimension; ++d ) + s[ d ] = TScalar( v[ d ] ); + this->_AddSample( s ); } // ------------------------------------------------------------------------- -template< class S, unsigned int D > -template< class V, class M > -void cpExtensions::Algorithms::IterativeGaussianModelEstimator< S, D >:: -GetModel( V& m, M& E ) const +template< class _TScalar, unsigned int _VDimension > +template< class _TOtherScalar > +_TScalar cpExtensions::Algorithms:: +IterativeGaussianModelEstimator< _TScalar, _VDimension >:: +SquaredMahalanobis( const _TOtherScalar& x1, ... ) const { - if( !this->m_Updated ) - this->_UpdateModel( ); - for( unsigned int i = 0; i < D; ++i ) - { - m[ i ] = double( this->m_M[ i ][ 0 ] ); - for( unsigned int j = 0; j < D; ++j ) - E[ i ][ j ] = double( this->m_Cov[ i ][ j ] ); - - } // rof + TVector s; + std::va_list lst; + va_start( lst, x1 ); + s[ 0 ] = TScalar( x1 ); + for( unsigned int d = 1; d < _VDimension; ++d ) + s[ d ] = TScalar( va_arg( lst, double ) ); + va_end( lst ); + return( this->_SquaredMahalanobis( s ) ); } // ------------------------------------------------------------------------- -template< class S, unsigned int D > -void cpExtensions::Algorithms::IterativeGaussianModelEstimator< S, D >:: -Clear( ) +template< class _TScalar, unsigned int _VDimension > +template< class _TOtherScalar > +_TScalar cpExtensions::Algorithms:: +IterativeGaussianModelEstimator< _TScalar, _VDimension >:: +SquaredMahalanobis( const _TOtherScalar* array ) const { - this->m_N = S( 0 ); - this->m_M.set_size( D, 1 ); - this->m_O.set_size( D, D ); - this->m_M.fill( S( 0 ) ); - this->m_O.fill( S( 0 ) ); - this->m_Updated = false; - this->Modified( ); + TVector s; + for( unsigned d = 0; d < _VDimension; ++d ) + s[ d ] = TScalar( array[ d ] ); + return( this->_SquaredMahalanobis( s ) ); } // ------------------------------------------------------------------------- -template< class S, unsigned int D > -template< class V > -void cpExtensions::Algorithms::IterativeGaussianModelEstimator< S, D >:: -AddSample( const V& sample ) +template< class _TScalar, unsigned int _VDimension > +template< class _TOtherScalar > +_TScalar cpExtensions::Algorithms:: +IterativeGaussianModelEstimator< _TScalar, _VDimension >:: +SquaredMahalanobis( const vnl_vector< _TOtherScalar >& v ) const { - TMatrix s( D, 1 ); - for( unsigned int d = 0; d < D; ++d ) - s[ d ][ 0 ] = S( sample[ d ] ); - - // Update mean - S coeff = this->m_N; - this->m_N += S( 1 ); - coeff /= this->m_N; - this->m_M = ( this->m_M * coeff ) + ( s / this->m_N ); - - // Update omega operand - if( this->m_N == 1 ) - this->m_O = s * s.transpose( ); - else if( this->m_N == 2 ) - this->m_O += s * s.transpose( ); - else - { - S inv = S( 1 ) / ( this->m_N - S( 1 ) ); - this->m_O = this->m_O * ( this->m_N - S( 2 ) ) * inv; - this->m_O += ( s * s.transpose( ) ) * inv; - - } // fi - - this->m_Updated = false; - this->Modified( ); + unsigned int len = ( v.size( ) < _VDimension )? v.size: _VDimension; + TVector s; + for( unsigned d = 0; d < len; ++d ) + s[ d ] = TScalar( v[ d ] ); + return( this->_SquaredMahalanobis( s ) ); } // ------------------------------------------------------------------------- -template< class S, unsigned int D > -void cpExtensions::Algorithms::IterativeGaussianModelEstimator< S, D >:: -AddSample( const S& s_x, const S& s_y, ... ) +template< class _TScalar, unsigned int _VDimension > +template< class _TOtherScalar > +_TScalar cpExtensions::Algorithms:: +IterativeGaussianModelEstimator< _TScalar, _VDimension >:: +SquaredMahalanobis( + const itk::CovariantVector< _TOtherScalar, _VDimension >& v + ) const { - static S sample[ D ]; + TVector s; + for( unsigned d = 0; d < _VDimension; ++d ) + s[ d ] = TScalar( v[ d ] ); + return( this->_SquaredMahalanobis( s ) ); +} - std::va_list args_lst; - va_start( args_lst, s_y ); - sample[ 0 ] = s_x; - if( D > 1 ) - { - sample[ 1 ] = s_y; - for( unsigned int d = 2; d < D; ++d ) - sample[ d ] = S( va_arg( args_lst, double ) ); - va_end( args_lst ); +// ------------------------------------------------------------------------- +template< class _TScalar, unsigned int _VDimension > +template< class _TOtherScalar > +_TScalar cpExtensions::Algorithms:: +IterativeGaussianModelEstimator< _TScalar, _VDimension >:: +SquaredMahalanobis( const itk::Point< _TOtherScalar, _VDimension >& p ) const +{ + TVector s; + for( unsigned d = 0; d < _VDimension; ++d ) + s[ d ] = TScalar( p[ d ] ); + return( this->_SquaredMahalanobis( s ) ); +} - } // fi - this->AddSample( sample ); +// ------------------------------------------------------------------------- +template< class _TScalar, unsigned int _VDimension > +template< class _TOtherScalar > +_TScalar cpExtensions::Algorithms:: +IterativeGaussianModelEstimator< _TScalar, _VDimension >:: +SquaredMahalanobis( const itk::Vector< _TOtherScalar, _VDimension >& v ) const +{ + TVector s; + for( unsigned d = 0; d < _VDimension; ++d ) + s[ d ] = TScalar( v[ d ] ); + return( this->_SquaredMahalanobis( s ) ); } // ------------------------------------------------------------------------- -template< class S, unsigned int D > -cpExtensions::Algorithms::IterativeGaussianModelEstimator< S, D >:: +template< class _TScalar, unsigned int _VDimension > +cpExtensions::Algorithms:: +IterativeGaussianModelEstimator< _TScalar, _VDimension >:: IterativeGaussianModelEstimator( ) : Superclass( ) { @@ -245,45 +199,56 @@ IterativeGaussianModelEstimator( ) } // ------------------------------------------------------------------------- -template< class S, unsigned int D > -cpExtensions::Algorithms::IterativeGaussianModelEstimator< S, D >:: +template< class _TScalar, unsigned int _VDimension > +cpExtensions::Algorithms:: +IterativeGaussianModelEstimator< _TScalar, _VDimension >:: ~IterativeGaussianModelEstimator( ) { } // ------------------------------------------------------------------------- -template< class S, unsigned int D > -void cpExtensions::Algorithms::IterativeGaussianModelEstimator< S, D >:: -_UpdateModel( ) const +template< class _TScalar, unsigned int _VDimension > +void cpExtensions::Algorithms:: +IterativeGaussianModelEstimator< _TScalar, _VDimension >:: +_AddSample( const TVector& v ) const { - static const double _2piD = - std::pow( double( 2 ) * double( vnl_math::pi ), D ); + this->m_NumberOfSamples += 1; + TScalar a = TScalar( 1 ) / TScalar( this->m_NumberOfSamples ); + TScalar b = TScalar( 1 ) - a; + TVector c = v - this->m_Mean; + TMatrix m; + for( unsigned int i = 0; i < _VDimension; ++i ) + { + m[ i ][ i ] = c[ i ] * c[ i ]; + for( unsigned int j = i + 1; j < _VDimension; ++j ) + m[ i ][ j ] = m[ j ][ i ] = c[ i ] * c[ j ]; - // Update covariance - this->m_Cov = - this->m_O - - ( - ( this->m_M * this->m_M.transpose( ) ) * - ( this->m_N / ( this->m_N - S( 1 ) ) ) - ); + } // rof + this->m_Covariance = ( this->m_Covariance + ( m * a ) ) * b; + this->m_Mean = ( this->m_Mean * b ) + ( v * a ); + + TScalar u = + TScalar( this->m_NumberOfSamples ) / + TScalar( this->m_NumberOfSamples - 1 ); + this->m_UnbiasedCovariance = this->m_Covariance * u; + this->m_InverseUpdated = false; +} - // Compute inverse and determinant - S det = vnl_determinant( this->m_Cov ); - if( !( det > S( 0 ) ) ) - { - this->m_Inv.set_size( D, D ); - this->m_Inv.fill( S( 0 ) ); - this->m_Norm = S( 0 ); - } - else +// ------------------------------------------------------------------------- +template< class _TScalar, unsigned int _VDimension > +_TScalar cpExtensions::Algorithms:: +IterativeGaussianModelEstimator< _TScalar, _VDimension >:: +_SquaredMahalanobis( const TVector& v ) const +{ + if( !this->m_InverseUpdated ) { - this->m_Inv = vnl_inverse( this->m_Cov ); - this->m_Norm = S( 1 ) / S( std::sqrt( _2piD * double( det ) ) ); + this->m_InverseUnbiasedCovariance = + this->m_UnbiasedCovariance.GetInverse( ); + this->m_InverseUpdated = true; } // fi - - // Object now is updated - this->m_Updated = true; + TVector x = v - this->m_Mean; + return( x * ( this->m_InverseUnbiasedCovariance * x ) ); } #endif // __CPEXTENSIONS__ALGORITHMS__ITERATIVEGAUSSIANMODELESTIMATOR__HXX__