jhpro.stat
Class EEcentricity

java.lang.Object
  extended by jhpro.stat.EEcentricity

public class EEcentricity
extends Object

A class for accentricity calculations using a principle component analysis. It calculates variances alone the principal axis and the eccentricity.


Constructor Summary
EEcentricity(double[] x, double[] y, double[] w)
          Initialize 2D PCA analysis
EEcentricity(P1D p1d)
          Perform PCA analysis using P1D object (in 2D).
 
Method Summary
 void doc()
          Show online documentation.
 double getAngle()
          Returns angle of ellipse rotation (angle of the principial axis)
 double getEccentricity()
          Get eccentricity, defined as 1-VarianceMin / VarianceMax.
 double getVarianceMax()
          Get variance alone the major axis (longest component)
 double getVarianceMin()
          Get variance alone the minor (shortest component)
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

EEcentricity

public EEcentricity(double[] x,
                    double[] y,
                    double[] w)
Initialize 2D PCA analysis

Parameters:
x - array in X
y - array in Y (the same size as for X)
w - points weights (can be set to 1 if all points are treated with the same weight)

EEcentricity

public EEcentricity(P1D p1d)
Perform PCA analysis using P1D object (in 2D). All weights for points are set to 1. X and Y component of P1D are used for the PCA.

Parameters:
p1d - P1D input objects
Method Detail

getAngle

public double getAngle()
Returns angle of ellipse rotation (angle of the principial axis)

Returns:
rotation angle (in rad)

getVarianceMin

public double getVarianceMin()
Get variance alone the minor (shortest component)

Returns:
minimum variance

getVarianceMax

public double getVarianceMax()
Get variance alone the major axis (longest component)

Returns:
minimum variance

getEccentricity

public double getEccentricity()
Get eccentricity, defined as 1-VarianceMin / VarianceMax. The value 0 corresponds to perfectly circular distribution, while 1 is for max. allongated

Returns:
eccentricity

doc

public void doc()
Show online documentation.



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