jhplot.stat

Class EEcentricity

java.lang.Object

jhplot.stat.EEcentricity

public class EEcentricity
extends Object

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

Constructor Summary

Constructors

Constructor and Description
EEcentricity(double[] x, double[] y, double[] w) Initialize 2D PCA analysis
EEcentricity(P1D p1d) Perform PCA analysis using P1D object (in 2D).

Method Summary

Modifier and Type	Method and Description
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.