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, signer@inf.ethz.ch

Constructor Summary

FeatureTool()

Method Summary

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)