edu.mit.sketch.util
Class LinearFit

java.lang.Object
  |
  +--edu.mit.sketch.util.LinearFit

public class LinearFit

extends Object

This class has useful functions for linear line matching. Some adapted from numerical recipes book.

Field Summary

static int	ROTATION_METHOD Constant corresponding to deriving direction using sliding window and rotation mehod.
static int	SIMPLE_TANGENTS_METHOD Constant corresponding to deriving direction using simple tangents.
static int	SWODR_METHOD Constant corresponding to deriving direction using sliding window and the ODR package.

Constructor Summary

LinearFit()

Method Summary

static double	findAngle(double[] x, double[] y) Return the angle -- in radians -- that best approximates the slope of the line that best fits x, y data points.
static double	findAngle(double[] x, double[] y, int start_index, int end_index) Return the angle -- in radians -- that best approximates the slope of the line that best fits x, y data points.
static double	findAngle(double[] x, double[] y, int start_index, int end_index, int partitions) Return the angle -- in radians -- that best approximates the slope of the line that best fits x, y data points.
static double	findAngle(Point[] points) Return the angle -- in radians -- that best approximates the slope of the line that best fits the data points.
static double	findAngle2(double[] x, double[] y, int start_index, int end_index, int depth) Return the angle -- in radians -- that best approximates the slope of the line that best fits x, y data points.
static double	findAngleViaODR(double[] x, double[] y) Do a linear fit.
static double[]	fit(double[] x, double[] y) Do a linear fit.
static double[]	fit2(double[] x, double[] y) Do a linear fit.
static String	fitMethodToString(int fit_method) Return a String giving info about the fit method.

Methods inherited from class java.lang.Object

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

Field Detail

SIMPLE_TANGENTS_METHOD

public static final int SIMPLE_TANGENTS_METHOD

Constant corresponding to deriving direction using simple tangents.

SWODR_METHOD

public static final int SWODR_METHOD

Constant corresponding to deriving direction using sliding window and the ODR package.

ROTATION_METHOD

public static final int ROTATION_METHOD

Constant corresponding to deriving direction using sliding window and rotation mehod.

Constructor Detail

LinearFit

public LinearFit()

Method Detail

fit

public static double[] fit(double[] x,
                           double[] y)

Do a linear fit. Return a and b in an array. (y = ax+b)

findAngle

public static double findAngle(double[] x,
                               double[] y,
                               int start_index,
                               int end_index,
                               int partitions)

Return the angle -- in radians -- that best approximates the slope of the line that best fits x, y data points. Do this for points [start_index, end_index] (including start and end points.

findAngle2

public static double findAngle2(double[] x,
                                double[] y,
                                int start_index,
                                int end_index,
                                int depth)

Return the angle -- in radians -- that best approximates the slope of the line that best fits x, y data points. Do this for points [start_index, end_index] (including start and end points.

findAngle

public static double findAngle(double[] x,
                               double[] y,
                               int start_index,
                               int end_index)

Return the angle -- in radians -- that best approximates the slope of the line that best fits x, y data points. Do this for points [start_index, end_index] (including start and end points.

findAngle

public static double findAngle(Point[] points)

Return the angle -- in radians -- that best approximates the slope of the line that best fits the data points.

findAngle

public static double findAngle(double[] x,
                               double[] y)

Return the angle -- in radians -- that best approximates the slope of the line that best fits x, y data points.

fit2

public static double[] fit2(double[] x,
                            double[] y)

Do a linear fit. Return a and b in an array. (y = ax+b)

findAngleViaODR

public static double findAngleViaODR(double[] x,
                                     double[] y)

Do a linear fit. Return then angle that the fitted line makes with the x axis.

fitMethodToString

public static String fitMethodToString(int fit_method)

Return a String giving info about the fit method.