#include <basic_pca.h>

Collaboration diagram for PCAonline:

Public Member Functions
	PCAonline ()
	Empty constructor. More...

void	addVector (MultidimArray< double > &y)

MultidimArray< double > &	getCurrentPCA ()
	Get principal component. More...

double	getCurrentProjection ()
	Get current projection. More...

Public Attributes
MultidimArray< double >	ysum

MultidimArray< double >	yxt

MultidimArray< double >	c1

MultidimArray< double >	ycentered

double	zn

double	xxt

int	N

double	maxzn

Detailed Description

Online PCA

Definition at line 159 of file basic_pca.h.

Constructor & Destructor Documentation

◆ PCAonline()

PCAonline::PCAonline ( )

Empty constructor.

Definition at line 519 of file basic_pca.cpp.

 {
     N=0;
 }

Member Function Documentation

◆ addVector()

void PCAonline::addVector ( MultidimArray< double > & y )

Add new vector. The input vector is centered according to the current average.

Definition at line 525 of file basic_pca.cpp.

 {
     if (N==0)
     {
         ysum=y;
         yxt.resizeNoCopy(y);
         c1.resizeNoCopy(y);
         ycentered.resizeNoCopy(y);
         N=1;
         zn=0;
     }
     else if (N==1)
     {
         xxt=0;
         FOR_ALL_DIRECT_ELEMENTS_IN_MULTIDIMARRAY(y)
         {
             double yval=DIRECT_MULTIDIM_ELEM(y,n);
             DIRECT_MULTIDIM_ELEM(yxt,n)=DIRECT_MULTIDIM_ELEM(c1,n)=yval-0.5*DIRECT_MULTIDIM_ELEM(ysum,n);// c1=y-ysum/2
             xxt+=DIRECT_MULTIDIM_ELEM(c1,n)*DIRECT_MULTIDIM_ELEM(c1,n);
         }
         c1/=sqrt(xxt); // Normalize c1
         zn=1;
         N=2;
     }
     else
     {
         double iN=1.0/N;
         zn=0;
         FOR_ALL_DIRECT_ELEMENTS_IN_MULTIDIMARRAY(y)
         {
             DIRECT_MULTIDIM_ELEM(ycentered,n)=DIRECT_MULTIDIM_ELEM(y,n)-iN*DIRECT_MULTIDIM_ELEM(ysum,n);// ycentered=y-ysum/N
             zn+=DIRECT_MULTIDIM_ELEM(c1,n)*DIRECT_MULTIDIM_ELEM(ycentered,n); // zn = ycentered^T c1
         }
         if (fabs(zn)>maxzn)
             return;
 
         xxt+=zn*zn;
         double ixxt=1.0/xxt;
         double c1norm=0;
         FOR_ALL_DIRECT_ELEMENTS_IN_MULTIDIMARRAY(y)
         {
             DIRECT_MULTIDIM_ELEM(ysum,n)+=DIRECT_MULTIDIM_ELEM(y,n); // ysum+=y
             DIRECT_MULTIDIM_ELEM(yxt,n)+=zn*DIRECT_MULTIDIM_ELEM(ycentered,n); // yxt+=zn*ycentered
             DIRECT_MULTIDIM_ELEM(c1,n)=ixxt*DIRECT_MULTIDIM_ELEM(yxt,n); // c1=yxt/xxt
             c1norm+=DIRECT_MULTIDIM_ELEM(c1,n)*DIRECT_MULTIDIM_ELEM(c1,n);
         }
         c1/=sqrt(c1norm);
         N++;
     }
 }

◆ getCurrentPCA()

MultidimArray<double>& PCAonline::getCurrentPCA ( )

inline

Get principal component.

Definition at line 179 of file basic_pca.h.

                                             {
         return c1;
     }

◆ getCurrentProjection()

double PCAonline::getCurrentProjection ( )

inline

Get current projection.

Definition at line 184 of file basic_pca.h.

                                   {
         return zn;
     }

Member Data Documentation

◆ c1

MultidimArray<double> PCAonline::c1

Definition at line 163 of file basic_pca.h.

◆ maxzn

double PCAonline::maxzn

Definition at line 168 of file basic_pca.h.

◆ N

int PCAonline::N

Definition at line 167 of file basic_pca.h.

◆ xxt

double PCAonline::xxt

Definition at line 166 of file basic_pca.h.

◆ ycentered

MultidimArray<double> PCAonline::ycentered

Definition at line 164 of file basic_pca.h.

◆ ysum

MultidimArray<double> PCAonline::ysum

Definition at line 161 of file basic_pca.h.

◆ yxt

MultidimArray<double> PCAonline::yxt

Definition at line 162 of file basic_pca.h.

◆ zn

double PCAonline::zn

Definition at line 165 of file basic_pca.h.

The documentation for this class was generated from the following files:

xmipp/libraries/data/basic_pca.h
xmipp/libraries/data/basic_pca.cpp

Public Member Functions

Public Attributes