edu.umbc.cs.maple.utils
Class MLUtils

java.lang.Object
  edu.umbc.cs.maple.utils.MLUtils

public class MLUtils
extends java.lang.Object

A collection of machine learning utility functions.

Copyright (c) 2008 Eric Eaton

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.

Version:

0.1

Author:

Eric Eaton (EricEaton@umbc.edu)
University of Maryland Baltimore County

Constructor Summary

MLUtils()

Method Summary

static java.awt.geom.Point2D[]	appendSortX(java.awt.geom.Point2D[] pts1, java.awt.geom.Point2D[] pts2) Combine two sorted vectors of points into one vector of sorted points.
static double[]	areaBetweenLearningCurves(java.awt.geom.Point2D[] baselineLearningCurve, java.awt.geom.Point2D[] targetLearningCurve) Given two learning curves, determines the area between the two curves.
static double	computePolygonArea(java.awt.geom.Point2D[] pts) Computes the area of the specified polygon.
static java.awt.geom.Point2D[]	cropLineX(java.awt.geom.Point2D[] line, double startingXcoord, double stoppingXcoord) Crops a line to the given x-coordinates.
static java.awt.geom.Point2D[]	ensureCurveHasXCoordinates(java.awt.geom.Point2D[] curve, double[] xCoords) Ensures that the given curve contains all of the specified x-coordinates.
static java.awt.geom.Point2D	interpolate(java.awt.geom.Point2D[] points, double x) Interpolates the given x onto the line of points.
static java.awt.geom.Point2D	interpolate(java.awt.geom.Point2D pt1, java.awt.geom.Point2D pt2, double x) Does linear interpolation at x of the line from pt1 to pt2.
static java.awt.geom.Point2D	intersection(java.awt.geom.Line2D lineA, java.awt.geom.Line2D lineB) Computes the intersection between two lines.
static boolean	isPointOnLine(java.awt.geom.Line2D line, java.awt.geom.Point2D point) Determines whether a given point is on a line.
static void	main(java.lang.String[] args)
static double	maxY(java.awt.geom.Point2D[] points) Determines the maximum y-coordinate for the set of points.
static double	minY(java.awt.geom.Point2D[] points) Determines the minimum y-coordinate for the set of points.
static double	normalizedAreaBetweenLearningCurves(java.awt.geom.Point2D[] baselineLearningCurve, java.awt.geom.Point2D[] targetLearningCurve, double bestPerformance) Calculates the normalized the area between these two learning curves by the area between the baselineLearningCurve and a horizontal line at the bestPerformance.

Methods inherited from class java.lang.Object

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

Constructor Detail

MLUtils

public MLUtils()

Method Detail

normalizedAreaBetweenLearningCurves

public static double normalizedAreaBetweenLearningCurves(java.awt.geom.Point2D[] baselineLearningCurve,
                                                         java.awt.geom.Point2D[] targetLearningCurve,
                                                         double bestPerformance)

Calculates the normalized the area between these two learning curves by the area between the baselineLearningCurve and a horizontal line at the bestPerformance.

Parameters:

baselineLearningCurve -

targetLearningCurve -

bestPerformance -

Returns:

the normalized area between the learning curves

main

public static void main(java.lang.String[] args)

areaBetweenLearningCurves

public static double[] areaBetweenLearningCurves(java.awt.geom.Point2D[] baselineLearningCurve,
                                                 java.awt.geom.Point2D[] targetLearningCurve)

Given two learning curves, determines the area between the two curves. This area has a sign based on the relationship between the baseline curve and the target curve. If the target curve is below the baseline, the sign will be negative; otherwise, it will be positive. If it is a mix of above and below, a negative sign would indicate that the target is more below the baseline than above it. Note that the baseline and target learning curves can have different starting and ending points from each other, and different points along the curves.

Parameters:

baselineLearningCurve - - the baseline learning curve vertices, in increasing order by x-coordinate

targetLearningCurve - - the target learning curve vertices, in increasing order by x-coordinate

Returns:

the area between the curves, the first x coordinate of this area, and the last x coordinate of this area.

ensureCurveHasXCoordinates

public static java.awt.geom.Point2D[] ensureCurveHasXCoordinates(java.awt.geom.Point2D[] curve,
                                                                 double[] xCoords)

Ensures that the given curve contains all of the specified x-coordinates.

Parameters:

curve - a curve specified by a set of points in sorted order by x-coordinate

xCoords - a set of x-coordinates, sorted in increasing order

Returns:

a curve containing all of the original points and any missing x-coordinates

computePolygonArea

public static double computePolygonArea(java.awt.geom.Point2D[] pts)

Computes the area of the specified polygon.

Parameters:

pts - the vertices specifying the polygon.

Returns:

the area of the specified polygon.

intersection

public static java.awt.geom.Point2D intersection(java.awt.geom.Line2D lineA,
                                                 java.awt.geom.Line2D lineB)

Computes the intersection between two lines. The calculated point is approximate, since integers are used. If you need a more precise result, use doubles everywhere. Modified from original version (by Alexander Hristov) by Eric Eaton. (c) 2007 Alexander Hristov. Use Freely (LGPL license). http://www.ahristov.com

Parameters:

lineA - the first line

lineB - the second line

Returns:

point where the segments intersect, or null if they don't

isPointOnLine

public static boolean isPointOnLine(java.awt.geom.Line2D line,
                                    java.awt.geom.Point2D point)

Determines whether a given point is on a line.

Parameters:

line -

point -

Returns:

whether the specified point is on the line

appendSortX

public static java.awt.geom.Point2D[] appendSortX(java.awt.geom.Point2D[] pts1,
                                                  java.awt.geom.Point2D[] pts2)

Combine two sorted vectors of points into one vector of sorted points.

Parameters:

pts1 -

pts2 -

Returns:

the vector of sorted points from pts1 and pts2

cropLineX

public static java.awt.geom.Point2D[] cropLineX(java.awt.geom.Point2D[] line,
                                                double startingXcoord,
                                                double stoppingXcoord)

Crops a line to the given x-coordinates.

Parameters:

line -

startingXcoord -

stoppingXcoord -

Returns:

the line cropped to the specified x-coordinates

interpolate

public static java.awt.geom.Point2D interpolate(java.awt.geom.Point2D pt1,
                                                java.awt.geom.Point2D pt2,
                                                double x)

Does linear interpolation at x of the line from pt1 to pt2.

Parameters:

pt1 - one endpoint of the line.

pt2 - another endpoint of the line.

x - the x-coordinate of the interpolated point.

Returns:

the desired interpolated point.

interpolate

public static java.awt.geom.Point2D interpolate(java.awt.geom.Point2D[] points,
                                                double x)

Interpolates the given x onto the line of points.

Parameters:

points -

x -

Returns:

x interpolated onto the line defined by the points

minY

public static double minY(java.awt.geom.Point2D[] points)

Determines the minimum y-coordinate for the set of points.

Parameters:

points -

Returns:

the minimum y-coordinate of the points

maxY

public static double maxY(java.awt.geom.Point2D[] points)

Determines the maximum y-coordinate for the set of points.

Parameters:

points -

Returns:

the maximum y-coordinate of the points