org.geotools.math
Class Plane

java.lang.Object
  org.geotools.math.Plane

All Implemented Interfaces:

java.lang.Cloneable, org.opengis.util.Cloneable, java.io.Serializable

public class Plane

extends java.lang.Object

implements org.opengis.util.Cloneable, java.io.Serializable

Equation of a plane in a three-dimensional space (x,y,z). The plane equation is expressed by c, cx and cy coefficients as below:

z(x,y) = c + cx*x + cy*y

Those coefficients can be set directly, or computed by a linear regression of this plane through a set of three-dimensional points.

Since:

2.0

Version:

$Id: Plane.java 17672 2006-01-19 00:25:55Z desruisseaux $

Author:

Martin Desruisseaux, Howard Freeland

See Also:

Serialized Form

Field Summary

double	c The c coefficient for this plane.
double	cx The cx coefficient for this plane.
double	cy The cy coefficient for this plane.

Constructor Summary

Plane()
Construct a new plane.

Method Summary

java.lang.Object	clone() Returns a clone of this plane.
boolean	equals(java.lang.Object object) Compare this plane with the specified object for equality.
int	hashCode() Returns a hash code value for this plane.
void	setPlane(double[] x, double[] y, double[] z) Compute the plane's coefficients from a set of points.
void	setPlane(javax.vecmath.Point3d P1, javax.vecmath.Point3d P2, javax.vecmath.Point3d P3) Computes the plane's coefficients from the specified points.
java.lang.String	toString() Returns a string representation of this plane.
double	x(double y, double z) Compute the x value for the specified (y,z) point.
double	y(double x, double z) Compute the y value for the specified (x,z) point.
double	z(double x, double y) Compute the z value for the specified (x,y) point.

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

c

public double c

The c coefficient for this plane. This coefficient appears in the place equation c+cx*x+cy*y.

cx

public double cx

The cx coefficient for this plane. This coefficient appears in the place equation c+cx*x+cy*y.

cy

public double cy

The cy coefficient for this plane. This coefficient appears in the place equation c+cx*x+cy*y.

Constructor Detail

Plane

public Plane()

Construct a new plane. All coefficients are set to 0.

Method Detail

z

public final double z(double x,
                      double y)

Compute the z value for the specified (x,y) point. The z value is computed using the following equation:

z(x,y) = c + cx*x + cy*y

Parameters:

x - The x value.

y - The y value.

Returns:

The z value.

y

public final double y(double x,
                      double z)

Compute the y value for the specified (x,z) point. The y value is computed using the following equation:

y(x,z) = (z - (c+cx*x)) / cy

Parameters:

x - The x value.

z - The y value.

Returns:

The y value.

x

public final double x(double y,
                      double z)

Compute the x value for the specified (y,z) point. The x value is computed using the following equation:

x(y,z) = (z - (c+cy*y)) / cx

Parameters:

y - The x value.

z - The y value.

Returns:

The x value.

setPlane

public void setPlane(javax.vecmath.Point3d P1,
                     javax.vecmath.Point3d P2,
                     javax.vecmath.Point3d P3)
              throws java.lang.ArithmeticException

Computes the plane's coefficients from the specified points. Three points are enough for determining exactly the plan, providing that the points are not colinear.

Throws:

java.lang.ArithmeticException - If the three points are colinear.

setPlane

public void setPlane(double[] x,
                     double[] y,
                     double[] z)
              throws javax.vecmath.MismatchedSizeException

Compute the plane's coefficients from a set of points. This method use a linear regression in the least-square sense. Result is undertermined if all points are colinear.

Parameters:

x - vector of x coordinates

y - vector of y coordinates

z - vector of z values

Throws:

javax.vecmath.MismatchedSizeException - if x, y and z don't have the same length.

toString

public java.lang.String toString()

Returns a string representation of this plane. The string will contains the plane's equation, as below:

z(x,y) = c + cx*x + cy*y

equals

public boolean equals(java.lang.Object object)

Compare this plane with the specified object for equality.

hashCode

public int hashCode()

Returns a hash code value for this plane.

clone

public java.lang.Object clone()

Returns a clone of this plane.

Specified by:

clone in interface org.opengis.util.Cloneable