edu.mit.sketch.toolkit
Class StrokeData

java.lang.Object
  edu.mit.sketch.toolkit.StrokeData

All Implemented Interfaces:

java.io.Serializable

public class StrokeData
extends java.lang.Object
implements java.io.Serializable

This class stores all the data from a single stroke. Time array has the same length as points.

See Also:

Serialized Form

Field Summary

boolean	a_is_valid
double[]	acceleration Time derivative of speed
double[]	accumulated_length The accumulated length of the curve upto ith vertex.
boolean	accumulated_length_is_valid
Rectangle	bounding_box
Point	center
double[]	d Direction array.
boolean	d_is_valid
double[]	dd_dt Derivative of the direction array (d).
Gaussian[]	dd_dt_gaussians
boolean	dd_dt_is_valid
double[][]	dd_dt_scale_space Direction change scale space information.
boolean	dd_dt_scale_space_is_valid
int	direction_window_width Parameters and constants.
LinearFit.Method	fit_method
PolarPoint[]	polar_points The vertices mapped to polar coordinates.
boolean	polar_points_is_valid
java.awt.Dimension	radius
double[]	speed Time derivative of position
Gaussian[]	speed_gaussians The gaussian filters.
double[][]	speed_scale_space Speed scale space information.
boolean	speed_scale_space_is_valid
double	test_line_scale
long[]	time The absolute time stamps for the vertices.
boolean	v_is_valid
Vertex[]	vertices The vertices in this data set.

Constructor Summary

StrokeData(double[] xs, double[] ys, double[] ts)
The constructor.

StrokeData(Point[] points_in)
Create a stroke from these points, and by default, remove duplicate points

StrokeData(Point[] points_in, boolean removeDupes)
The constructor.

StrokeData(Vertex[] vertices_in)
The constructor.

Method Summary

static double	absAverage(double[] l)
static double	average(double[] l)
double	averageAbsoluteFinG(double[] f, double[] g) Average
double	averageAbsoluteFinG(double[] f, long[] g) Average
double	averageFinG(double[] f, double[] g) Average
double	averageFinG(double[] f, long[] g) Average
double	averageSpeed() Average speed
void	convolveChangeInDirection(double[] filter) Do convolution.
void	convolveDirection(double[] filter) Do convolution.
double	cosAngle(Point p, Point pl, Point pr)
void	derive_accumulated_length() Compute the derive accumulated length.
void	derive_d(LinearFit.Method method) Derive direction, and fill in the d array.
void	derive_dd_dt_scale_space() Compute the scale space data.
void	derive_dd_dt() Find time derivative of direction, and fill in the dd_dt array.
void	derive_speed_scale_space() Compute the scale space data.
void	deriveAcceleration() Derive acceleration, and fill in the acceleration array.
void	deriveBoundingBox() Derive the bounding box for the vertices.
double[]	deriveDirectionUsingRotationalSWODR(Point[] input, int window_span) Derive direction, and return it.
double[]	deriveDirectionViaSWODR(Point[] input, int twice_window_size) Derive direction, and fill in the d array.
void	derivePolarCoordinates() Derive the polar coordinates of the vertices with respect to the center.
void	derivePolarCoordinates(double x, double y, int width, int height)
void	deriveProperties() Derive speed, and fill in the speed array.
void	deriveScaleSpaces() Derive speed, and fill in the speed array.
void	deriveSpeed() Derive speed, and fill in the speed array.
double	diagnolLength()
double[]	differantiateDirection(double[] direction) Differantiate the direction array using the current timing data.
int[]	filterCollinearVertices(int[] indices) filterCollinearVertices.
int[]	filterVerticesByLSQE(int[] indices, double percentTolerance) filterCollinearVertices.
Vertex[]	filterVerticesByLSQE(Vertex[] vertices, double percentTolerance) filterCollinearVertices.
int[]	filterVerticesDownToN(int[] inds, int num)
Vertex[]	filterVerticesDownToN(Vertex[] verts, int num)
Vertex[]	filterVerticesDownToN(Vertex[] verts, int num, double errorBound)
double[]	getAngles() Get the directions for each of the vertex points.
Rectangle	getBoundingBox() Get the bounding box for this stroke.
Polygon	getDataPoints() Put the valid points in the points array in a Polygon and return it.
Vertex[]	getDirectionFit(double dd_dt_scale) Find the corners of the polygon using the change in the direction.
Ellipse	getEllipse() Return the ellipse fully containing the data points.
Ellipse	getEllipseBB()
long	getEndTime()
int	getNumVertices()
java.awt.geom.Rectangle2D	getOriginalBounds() Get the bounding box of the original points instead of the filtered points.
Point[]	getOrigPoints()
Vertex[]	getPolygonFit(double threshold, int min_size) Finds a polygon approximation using the a greedy error threshold method
java.lang.Object	getProperty(java.lang.String name) Get a property's value.
java.lang.Object	getProperty(java.lang.String name, java.lang.Object defaultVal) Get a property's value.
Vertex[]	getSpeedFit(double average_scale) Return the speed fit
long	getStartTime()
double	getStrokeLength()
StrokeData	getTranslated(double dx, double dy) Get a copy of this stroke data object translated by (x,y)
Vertex[]	getVertices() Return the vertices array.
StrokeData	interpolatePoints(double maxDist) This interpolates points along the stroke such that there is never more than maxDist between adjacent points.
void	invalidateCaches() Invalidates caches
double	leastSquaresForCircle()
double	leastSquaresForCircle2() calculate the lsq error.
double	leastSquaresForEllipse() calculate the lsq error.
static void	main(java.lang.String[] args)
static double[]	normalize(double[] l)
void	paint(java.awt.Graphics g) Paint
void	paint(java.awt.Graphics g, Range range, java.awt.Color c) Paint points in range with color c
Point[]	removeDuplicatePoints(Point[] points_in) Remove points w/repeating (x,y) or t
Vertex[]	removeDuplicateVertices(Vertex[] vertices_in) Remove vertices w/repeating (x,y) or t
Point[]	removeHooks(Point[] points_in) Removes hook artifacts, signified by regions of high curvature within 10 pixels of the beginning or end of a stroke
java.lang.Object	removeProperty(java.lang.String name) Remove the mapping for the given property.
Vertex[]	removeRedundantEndPoints(Vertex[] input_points) Remove the redundant at the beginning and the end.
void	setFitMethod(LinearFit.Method method) Set fit method
void	setOrigPoints(Point[] points)
void	setProperty(java.lang.String name, java.lang.Object value) Set a property to the given value.
Vertex[]	smFit(double tolerance) Return the split and merge fit.
boolean	testLine(double test_line_scale) See if the input is a line.
java.lang.String	toString()

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

vertices

public Vertex[] vertices

The vertices in this data set.

time

public long[] time

The absolute time stamps for the vertices.

speed

public transient double[] speed

Time derivative of position

acceleration

public transient double[] acceleration

Time derivative of speed

d

public transient double[] d

Direction array. Length of this array is the same as the length of the vertices array. Basically the direction (ie. the angle of the tangent) at the last point in vertices is just the same as that of the previous point.

dd_dt

public transient double[] dd_dt

Derivative of the direction array (d). The length of this array is one less than that of d.

accumulated_length

public transient double[] accumulated_length

The accumulated length of the curve upto ith vertex.

speed_scale_space

public transient double[][] speed_scale_space

Speed scale space information. The rightmost dimension indexes the speed values at different scales, and the leftmost dimension indexes the scale parameter. Higher values correspond to coarser scales.

dd_dt_scale_space

public transient double[][] dd_dt_scale_space

Direction change scale space information. The rightmost dimension indexes the data values at different scales, and the leftmost dimension indexes the scale parameter. Higher values correspond to coarser scales.

speed_gaussians

public transient Gaussian[] speed_gaussians

The gaussian filters.

dd_dt_gaussians

public transient Gaussian[] dd_dt_gaussians

polar_points

public PolarPoint[] polar_points

The vertices mapped to polar coordinates.

direction_window_width

public int direction_window_width

Parameters and constants.

fit_method

public LinearFit.Method fit_method

test_line_scale

public double test_line_scale

center

public Point center

bounding_box

public Rectangle bounding_box

radius

public java.awt.Dimension radius

v_is_valid

public boolean v_is_valid

a_is_valid

public boolean a_is_valid

d_is_valid

public boolean d_is_valid

dd_dt_is_valid

public boolean dd_dt_is_valid

polar_points_is_valid

public boolean polar_points_is_valid

accumulated_length_is_valid

public boolean accumulated_length_is_valid

dd_dt_scale_space_is_valid

public boolean dd_dt_scale_space_is_valid

speed_scale_space_is_valid

public boolean speed_scale_space_is_valid

Constructor Detail

StrokeData

public StrokeData(double[] xs,
                  double[] ys,
                  double[] ts)

The constructor.

StrokeData

public StrokeData(Vertex[] vertices_in)

The constructor.

StrokeData

public StrokeData(Point[] points_in,
                  boolean removeDupes)

The constructor.

StrokeData

public StrokeData(Point[] points_in)

Create a stroke from these points, and by default, remove duplicate points

Parameters:

points_in - The points making up the stroke

Method Detail

getOrigPoints

public Point[] getOrigPoints()

setOrigPoints

public void setOrigPoints(Point[] points)

removeDuplicatePoints

public Point[] removeDuplicatePoints(Point[] points_in)

Remove points w/repeating (x,y) or t

removeDuplicateVertices

public Vertex[] removeDuplicateVertices(Vertex[] vertices_in)

Remove vertices w/repeating (x,y) or t

removeHooks

public Point[] removeHooks(Point[] points_in)

Removes hook artifacts, signified by regions of high curvature within 10 pixels of the beginning or end of a stroke

cosAngle

public double cosAngle(Point p,
                       Point pl,
                       Point pr)

interpolatePoints

public StrokeData interpolatePoints(double maxDist)

This interpolates points along the stroke such that there is never more than maxDist between adjacent points. The distance will not necessarily be constant, it only gaurantees that the distance will be less than the given amount.

Parameters:

maxDist - Max distance allowed between consequtive points

Returns:

The interpolated points in a new stroke

deriveProperties

public void deriveProperties()

Derive speed, and fill in the speed array. This method should cache data in order to save computation.

deriveScaleSpaces

public void deriveScaleSpaces()

Derive speed, and fill in the speed array. This method should cache data in order to save computation.

invalidateCaches

public void invalidateCaches()

Invalidates caches

getVertices

public Vertex[] getVertices()

Return the vertices array.

getAngles

public double[] getAngles()

Get the directions for each of the vertex points. This shares the same indexes as the vertexes array.

getBoundingBox

public Rectangle getBoundingBox()

Get the bounding box for this stroke.

Returns:

The bounding box of this stroke

derivePolarCoordinates

public void derivePolarCoordinates()

Derive the polar coordinates of the vertices with respect to the center. Also determine the upper_right and lower right points (for surrounding rectangle).

derivePolarCoordinates

public void derivePolarCoordinates(double x,
                                   double y,
                                   int width,
                                   int height)

deriveBoundingBox

public void deriveBoundingBox()

Derive the bounding box for the vertices.

getOriginalBounds

public java.awt.geom.Rectangle2D getOriginalBounds()

Get the bounding box of the original points instead of the filtered points. Return the result as a Rectangle2D to preserve the double precision.

Returns:

The BBox of the original points

getStartTime

public long getStartTime()

getEndTime

public long getEndTime()

deriveSpeed

public void deriveSpeed()

Derive speed, and fill in the speed array. This method should cache data in order to save computation.

deriveAcceleration

public void deriveAcceleration()

Derive acceleration, and fill in the acceleration array.

derive_d

public void derive_d(LinearFit.Method method)

Derive direction, and fill in the d array.

derive_dd_dt

public void derive_dd_dt()

Find time derivative of direction, and fill in the dd_dt array.

derive_accumulated_length

public void derive_accumulated_length()

Compute the derive accumulated length.

derive_dd_dt_scale_space

public void derive_dd_dt_scale_space()

Compute the scale space data.

derive_speed_scale_space

public void derive_speed_scale_space()

Compute the scale space data.

filterVerticesDownToN

public Vertex[] filterVerticesDownToN(Vertex[] verts,
                                      int num)

filterVerticesDownToN

public Vertex[] filterVerticesDownToN(Vertex[] verts,
                                      int num,
                                      double errorBound)

filterVerticesDownToN

public int[] filterVerticesDownToN(int[] inds,
                                   int num)

filterVerticesByLSQE

public Vertex[] filterVerticesByLSQE(Vertex[] vertices,
                                     double percentTolerance)

filterCollinearVertices.

filterVerticesByLSQE

public int[] filterVerticesByLSQE(int[] indices,
                                  double percentTolerance)

filterCollinearVertices.

filterCollinearVertices

public int[] filterCollinearVertices(int[] indices)

filterCollinearVertices.

deriveDirectionUsingRotationalSWODR

public double[] deriveDirectionUsingRotationalSWODR(Point[] input,
                                                    int window_span)

Derive direction, and return it. This method is different than the previous one in that here we look at a collection of vertices rather than two vertices to come up with the direction. Also use the rotation method.

deriveDirectionViaSWODR

public double[] deriveDirectionViaSWODR(Point[] input,
                                        int twice_window_size)

Derive direction, and fill in the d array. This method is different than the previous one in that here we look at a collection of vertices rather than two vertices to find the direction. Also this is supposed to work faster. Returns the direction array.

differantiateDirection

public double[] differantiateDirection(double[] direction)

Differantiate the direction array using the current timing data.

averageSpeed

public double averageSpeed()

Average speed

averageFinG

public double averageFinG(double[] f,
                          double[] g)

Average

averageAbsoluteFinG

public double averageAbsoluteFinG(double[] f,
                                  double[] g)

Average

averageFinG

public double averageFinG(double[] f,
                          long[] g)

Average

averageAbsoluteFinG

public double averageAbsoluteFinG(double[] f,
                                  long[] g)

Average

getDataPoints

public Polygon getDataPoints()

Put the valid points in the points array in a Polygon and return it.

smFit

public Vertex[] smFit(double tolerance)

Return the split and merge fit. Tolerance in pixels

getSpeedFit

public Vertex[] getSpeedFit(double average_scale)

Return the speed fit

getDirectionFit

public Vertex[] getDirectionFit(double dd_dt_scale)

Find the corners of the polygon using the change in the direction. This is basically done by finding the peaks of the dd_dt array.

normalize

public static double[] normalize(double[] l)

average

public static double average(double[] l)

absAverage

public static double absAverage(double[] l)

getPolygonFit

public Vertex[] getPolygonFit(double threshold,
                              int min_size)

Finds a polygon approximation using the a greedy error threshold method

diagnolLength

public double diagnolLength()

testLine

public boolean testLine(double test_line_scale)

See if the input is a line.

getEllipse

public Ellipse getEllipse()

Return the ellipse fully containing the data points.

getEllipseBB

public Ellipse getEllipseBB()

leastSquaresForEllipse

public double leastSquaresForEllipse()

calculate the lsq error.

leastSquaresForCircle

public double leastSquaresForCircle()

leastSquaresForCircle2

public double leastSquaresForCircle2()

calculate the lsq error.

removeRedundantEndPoints

public Vertex[] removeRedundantEndPoints(Vertex[] input_points)

Remove the redundant at the beginning and the end.

setFitMethod

public void setFitMethod(LinearFit.Method method)

Set fit method

convolveDirection

public void convolveDirection(double[] filter)

Do convolution.

convolveChangeInDirection

public void convolveChangeInDirection(double[] filter)

Do convolution.

paint

public void paint(java.awt.Graphics g)

Paint

getNumVertices

public int getNumVertices()

getTranslated

public StrokeData getTranslated(double dx,
                                double dy)

Get a copy of this stroke data object translated by (x,y)

Parameters:

dx - Translate this far in x

dy - Translate this far in y

Returns:

A new StrokeData translated by the given amount

paint

public void paint(java.awt.Graphics g,
                  Range range,
                  java.awt.Color c)

Paint points in range with color c

getStrokeLength

public double getStrokeLength()

setProperty

public void setProperty(java.lang.String name,
                        java.lang.Object value)

Set a property to the given value. This can be used for things like names, ids, etc...

getProperty

public java.lang.Object getProperty(java.lang.String name)

Get a property's value. This can be used for things like names, ids, etc...

getProperty

public java.lang.Object getProperty(java.lang.String name,
                                    java.lang.Object defaultVal)

Get a property's value. This can be used for things like names, ids, etc...

removeProperty

public java.lang.Object removeProperty(java.lang.String name)

Remove the mapping for the given property. It returns the value of the removed key. (note: null may mean no such property or that the properties value was null)

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

main

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