databionics.math
Class Distances

java.lang.Object
  databionics.math.Distances

Direct Known Subclasses:

ParetoDensity

public class Distances
extends java.lang.Object

Computes all pairwise distances between row vectors of a DoubleMatrix2D. In contrast to Statistic.distance the values are stored in a DoubeArrayList of length N(N-1)/2 rather than in a DoubleMatrix2D.

Field Summary

protected cern.colt.matrix.DoubleMatrix1D[]	data
protected cern.colt.matrix.DoubleMatrix2D	data2d
protected cern.colt.function.VectorVectorFunction	distanceFunction
protected cern.colt.matrix.DoubleMatrix1D	distances
protected static org.apache.log4j.Logger	log
protected int	n

Constructor Summary

Distances()

Method Summary

protected void	calculateDistances()
double	get(int i, int j) Get the distance between row i and j of the original data matrix
cern.colt.matrix.DoubleMatrix2D	getData()
cern.colt.function.VectorVectorFunction	getDistanceFunction()
cern.colt.matrix.DoubleMatrix2D	getDistanceMatrix() getting the pairwise distances from matrix/vector set in setData().
cern.colt.matrix.DoubleMatrix1D	getDistances() getting the pairwise distances from matrix/vector invoked in setData().
void	set(int i, int j, double d) set distance between i and j to d
void	setData(cern.colt.matrix.DoubleMatrix1D d)
void	setData(cern.colt.matrix.DoubleMatrix1D[] d)
void	setData(cern.colt.matrix.DoubleMatrix2D d)
void	setDistanceFunction(cern.colt.function.VectorVectorFunction d) set the function to calculate distances.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

log

protected static org.apache.log4j.Logger log

distanceFunction

protected cern.colt.function.VectorVectorFunction distanceFunction

data2d

protected cern.colt.matrix.DoubleMatrix2D data2d

data

protected cern.colt.matrix.DoubleMatrix1D[] data

distances

protected cern.colt.matrix.DoubleMatrix1D distances

n

protected int n

Constructor Detail

Distances

public Distances()

Method Detail

getDistances

public cern.colt.matrix.DoubleMatrix1D getDistances()
                                             throws java.lang.NullPointerException

getting the pairwise distances from matrix/vector invoked in setData(). If distance function is not set, euclidian distance is used

Returns:

Distances of data matrix

Throws:

java.lang.NullPointerException

getDistanceMatrix

public cern.colt.matrix.DoubleMatrix2D getDistanceMatrix()
                                                  throws java.lang.NullPointerException

getting the pairwise distances from matrix/vector set in setData(). If distance function is not set, euclidian distance is used

Returns:

Distances of data matrix

Throws:

java.lang.NullPointerException

get

public double get(int i,
                  int j)
           throws java.lang.NullPointerException

Get the distance between row i and j of the original data matrix

Parameters:

i - row number of first data vector

j - row number of second data vector

Returns:

distance between rows i and j

Throws:

java.lang.NullPointerException

setDistanceFunction

public void setDistanceFunction(cern.colt.function.VectorVectorFunction d)

set the function to calculate distances. Former calculation of distances are reset to null.

Parameters:

VectorVectorFunction - distanceFunction

getDistanceFunction

public cern.colt.function.VectorVectorFunction getDistanceFunction()

setData

public void setData(cern.colt.matrix.DoubleMatrix2D d)

setData

public void setData(cern.colt.matrix.DoubleMatrix1D d)

setData

public void setData(cern.colt.matrix.DoubleMatrix1D[] d)

set

public void set(int i,
                int j,
                double d)

set distance between i and j to d

Parameters:

i -

j -

d -

calculateDistances

protected void calculateDistances()

getData

public cern.colt.matrix.DoubleMatrix2D getData()
                                        throws java.lang.NullPointerException

Returns:

Returns the data (for equality-check)

Throws:

java.lang.NullPointerException