org.ximtec.igesture.algorithm.feature

Class FeatureTool

java.lang.Object

org.ximtec.igesture.algorithm.feature.FeatureTool

public class FeatureTool
extends Object

Some feature tools.

Version:

1.0 Dec 2006

Author:

Ueli Kurmann, igesture@uelikurmann.ch, Beat Signer, bsigner@vub.ac.be

Constructor Summary

Constructors

Constructor and Description
FeatureTool()

Method Summary

Methods

Modifier and Type	Method and Description
static double	computeD1(org.sigtec.ink.Note note)
static double	computeD2(org.sigtec.ink.Note note)
static double	computeD3(org.sigtec.ink.Note note)
static DoubleVector	computeFeatureVector(org.sigtec.ink.Note note, int minDistance, Feature[] featureList) Computes the feature vector.
static int	computeMinimalNumberOfRequiredPoints(Feature[] list) Returns the minimal number of points a note must contain to be processed.
static Feature	createFeature(String classname) Instantiates a feature of the given full qualified classname.
static List<Feature>	createFeatureList(String featureList) Creates a list of instantiated features out of a comma delimited list of full qualified feature classnames.
static org.sigtec.ink.Trace	createTrace(org.sigtec.ink.Note note) Takes a note and returns a single trace containing all points.
static double	getAngle(org.sigtec.ink.Point p1, org.sigtec.ink.Point p2) Computes the angle of the line p1-p2 in the unit circle.
static double	getDeltaT(int i, org.sigtec.ink.Point[] points) Returns the difference of the timestamps in point i and i + 1.
static double	getDeltaT(org.sigtec.ink.Point p1, org.sigtec.ink.Point p2) Returns the difference of the timestamps in point p1 and p2.
static double	getDeltaX(int i, org.sigtec.ink.Point[] points) Returns the distance in respect to the X axis between point i and i+1.
static double	getDeltaY(int i, org.sigtec.ink.Point[] points) Returns the distance in respect to the Y axis between point i and i+1.
static List<org.sigtec.ink.Trace>	removeShortTraces(List<org.sigtec.ink.Trace> traces, int minNumOfPoints) Removes traces from the list with less than minNumOfPoints.
static double	roh(int i, org.sigtec.ink.Point[] points) Computes the angle in respect to the x axis in point i and i-1.

Methods inherited from class java.lang.Object

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

Constructor Detail

FeatureTool

public FeatureTool()

Method Detail

createTrace

public static org.sigtec.ink.Trace createTrace(org.sigtec.ink.Note note)

Takes a note and returns a single trace containing all points.

Parameters:

note - the note whose points have to be extracted.

Returns:

the trace containing all points of the note.

getDeltaX

public static double getDeltaX(int i,
               org.sigtec.ink.Point[] points)

Returns the distance in respect to the X axis between point i and i+1.

Parameters:

i - the ith point.

points - the array of points.

Returns:

the distance in respect to the X axis between point i and i+1.

getDeltaY

public static double getDeltaY(int i,
               org.sigtec.ink.Point[] points)

Returns the distance in respect to the Y axis between point i and i+1.

Parameters:

i - the ith point.

points - the array of points.

Returns:

the distance in respect to the Y axis between point i and i+1.

getDeltaT

public static double getDeltaT(int i,
               org.sigtec.ink.Point[] points)

Returns the difference of the timestamps in point i and i + 1.

Parameters:

i - the ith point.

points - the array of points.

Returns:

the time between two points.

getDeltaT

public static double getDeltaT(org.sigtec.ink.Point p1,
               org.sigtec.ink.Point p2)

Returns the difference of the timestamps in point p1 and p2.

Parameters:

p1 - the point p1.

p2 - the point p2.

Returns:

the time passes between the two given points.

roh

public static double roh(int i,
         org.sigtec.ink.Point[] points)

Computes the angle in respect to the x axis in point i and i-1.

Parameters:

i - the index of the point to be used in the computation.

points - the set of points.

Returns:

the angle relative to the x axis for point i and i-1.

getAngle

public static double getAngle(org.sigtec.ink.Point p1,
              org.sigtec.ink.Point p2)

Computes the angle of the line p1-p2 in the unit circle.

Parameters:

p1 - start point of the line.

p2 - end point of the line.

Returns:

the angle.

removeShortTraces

public static List<org.sigtec.ink.Trace> removeShortTraces(List<org.sigtec.ink.Trace> traces,
                                           int minNumOfPoints)

Removes traces from the list with less than minNumOfPoints.

Parameters:

traces - the list of traces.

minNumOfPoints - the minimal number of points a trace must contain.

Returns:

the filtered list of traces.

createFeatureList

public static List<Feature> createFeatureList(String featureList)

Creates a list of instantiated features out of a comma delimited list of full qualified feature classnames.

Parameters:

featureList - a comma delimited list of full qualified class names.

Returns:

list of feature instances.

createFeature

public static Feature createFeature(String classname)

Instantiates a feature of the given full qualified classname.

Parameters:

classname - the full qualified class name.

Returns:

the instance of the feature.

computeFeatureVector

public static DoubleVector computeFeatureVector(org.sigtec.ink.Note note,
                                int minDistance,
                                Feature[] featureList)
                                         throws FeatureException

Computes the feature vector.

Parameters:

note - the note the feature vector has to be computed of.

minDistance - the minimal distance between two points.

featureList - an array of features.

Returns:

the feature vector.

Throws:

FeatureException - if the feature vector cannot be computed.

computeMinimalNumberOfRequiredPoints

public static int computeMinimalNumberOfRequiredPoints(Feature[] list)

Returns the minimal number of points a note must contain to be processed.

Parameters:

list - the list of features.

Returns:

the minimal number of points a note must contain.

computeD1

public static double computeD1(org.sigtec.ink.Note note)

computeD2

public static double computeD2(org.sigtec.ink.Note note)

computeD3

public static double computeD3(org.sigtec.ink.Note note)