edu.udo.cs.yale.example
Class DoubleSparseArrayDataRow

java.lang.Object
  edu.udo.cs.yale.example.DoubleSparseArrayDataRow

All Implemented Interfaces:

DataRow, SparseDataRow

public class DoubleSparseArrayDataRow
extends java.lang.Object
implements DataRow, SparseDataRow

Implementation of DataRow that is backed by primitive arrays. Should always be used if more than 50% of the data is sparse. As fast (or even faster than map implementation) but needs considerably less memory.

Version:

$Id: DoubleSparseArrayDataRow.java,v 2.10 2006/03/21 15:35:39 ingomierswa Exp $

Author:

Niraj Aswani, Julien Nioche, Ingo Mierswa

Field Summary

private int	counter Number of inserted elements.
private double[]	values Stores the used attribute values.
private int[]	x Stores the used attribute indices.

Constructor Summary

DoubleSparseArrayDataRow()
Creates an empty sparse array data row with size 0.

DoubleSparseArrayDataRow(int size)
Creates a sparse array data row of the given size.

Method Summary

void	ensureNumberOfColumns(int numberOfColumns) Does nothing.
double	get(Attribute attribute) Returns the desired data for the given attribute.
int[]	getNonDefaultIndices() Returns an array of all attribute indices with corresponding non-default values.
double[]	getNonDefaultValues() Returns an array of all non-default attribute values.
private int	med3(int a, int b, int c)
void	set(Attribute attribute, double value) Sets the given data for the given attribute.
private void	sort(int off, int len) Sorts the arrays in the given range.
private void	swap(int a, int b) Swaps x[a] with x[b].
java.lang.String	toString() Returns a string representation of the data row.
void	trim() Trims the data row to the number of actually used elements.
private void	vecswap(int a, int b, int n) Swaps the next n elements from a and b.

Methods inherited from class java.lang.Object

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

Field Detail

x

private int[] x

Stores the used attribute indices.

values

private double[] values

Stores the used attribute values.

counter

private int counter

Number of inserted elements.

Constructor Detail

DoubleSparseArrayDataRow

public DoubleSparseArrayDataRow()

Creates an empty sparse array data row with size 0.

DoubleSparseArrayDataRow

public DoubleSparseArrayDataRow(int size)

Creates a sparse array data row of the given size.

Method Detail

sort

private void sort(int off,
                  int len)

Sorts the arrays in the given range.

vecswap

private void vecswap(int a,
                     int b,
                     int n)

Swaps the next n elements from a and b.

med3

private int med3(int a,
                 int b,
                 int c)

swap

private void swap(int a,
                  int b)

Swaps x[a] with x[b].

get

public double get(Attribute attribute)

Returns the desired data for the given attribute.

Specified by:

get in interface DataRow

set

public void set(Attribute attribute,
                double value)

Sets the given data for the given attribute.

Specified by:

set in interface DataRow

getNonDefaultIndices

public int[] getNonDefaultIndices()

Description copied from interface: SparseDataRow

Returns an array of all attribute indices with corresponding non-default values.

Specified by:

getNonDefaultIndices in interface SparseDataRow

getNonDefaultValues

public double[] getNonDefaultValues()

Description copied from interface: SparseDataRow

Returns an array of all non-default attribute values.

Specified by:

getNonDefaultValues in interface SparseDataRow

ensureNumberOfColumns

public void ensureNumberOfColumns(int numberOfColumns)

Does nothing.

Specified by:

ensureNumberOfColumns in interface DataRow

trim

public void trim()

Trims the data row to the number of actually used elements.

Specified by:

trim in interface DataRow

toString

public java.lang.String toString()

Returns a string representation of the data row.

Overrides:

toString in class java.lang.Object