maspack.matrix
Class AffineTransform2dObject

java.lang.Object
  maspack.matrix.MatrixObject
      maspack.matrix.AffineTransform2dObject

Direct Known Subclasses:

AffineTransform2d, RigidTransform2d

public class AffineTransform2dObject

extends MatrixObject

Base class for 3 x 3 matrices representing 2D affine transformations. A 2D affine transformation applied to a 2-vector v has the form
A v + b
In homogeneous coordinates, this is represented by a 3 x 3 matrix of the form

     [  A   p  ]
 M = [         ]
     [  0   1  ]
 

Constructor Summary

AffineTransform2dObject()

Method Summary

int	colSize() Returns the number of columns in this matrix (which is always 3).
boolean	epsilonEquals(AffineTransform2dObject X, double epsilon) Returns true if the elements of this transformation equal those of transform X1within a prescribed tolerance epsilon.
boolean	equals(AffineTransform2dObject X) Returns true if the elements of this transformation exactly equal those of transform X1.
void	get(double[] values) Copies the elements of this matrix into an array of doubles. The elements are stored using row-major order, so that element (i,j) is stored at location i*colSize()+j.
double	get(int i, int j) Gets a single element of this matrix.
void	getColumn(int j, double[] values) Copies a column of this matrix into an array of doubles.
void	getRow(int i, double[] values) Copies a row of this matrix into an array of doubles.
boolean	invert() Inverts this transform in place.
void	mul(Vector3d vr) Multiplies the column vector vr by this transform and places the result back in vr.
void	mul(Vector3d vr, Vector3d v1) Multiplies the column vector v1 by this transform and places the result in vr.
boolean	mulInverse(Vector3d vr) Multiplies the column vector vr by the inverse of this transform and places the result back in vr.
boolean	mulInverse(Vector3d vr, Vector3d v1) Multiplies the column vector v1 by the inverse of this transform and places the result in vr.
int	rowSize() Returns the number of rows in this matrix (which is always 3).
void	set(double[] vals) Sets the elements of this matrix from an array of doubles. The elements in the array should be stored using row-major order, so that element (i,j) is stored at location i*colSize()+j.
void	set(int i, int j, double value) Sets a single element of this matrix.
void	set(RigidTransform2d X) Sets this affine transform to the rigid body transform described by X.
void	setColumn(int j, double[] values) Sets a column of this matrix from an array of doubles.
void	setIdentity() Sets the transformation to the identity.
void	setRow(int i, double[] values) Set a row of this matrix from an array of doubles.

Methods inherited from class maspack.matrix.MatrixObject

determinant, epsilonEquals, equals, equals, frobeniusNorm, get, getColumn, getRow, infinityNorm, isFixedSize, oneNorm, scan, set, set, setColumn, setRow, setSize, toString, toString, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

AffineTransform2dObject

public AffineTransform2dObject()

Method Detail

colSize

public int colSize()

Returns the number of columns in this matrix (which is always 3).

Specified by:

colSize in class MatrixObject

Returns:

3

rowSize

public int rowSize()

Returns the number of rows in this matrix (which is always 3).

Specified by:

rowSize in class MatrixObject

Returns:

3

get

public double get(int i,
                  int j)

Gets a single element of this matrix.

Specified by:

get in class MatrixObject

Parameters:

i - element row index

j - element column index

Returns:

element value

get

public void get(double[] values)

Copies the elements of this matrix into an array of doubles. The elements are stored using row-major order, so that element (i,j) is stored at location i*colSize()+j.

Overrides:

get in class MatrixObject

Parameters:

values - array into which values are copied

getColumn

public void getColumn(int j,
                      double[] values)

Copies a column of this matrix into an array of doubles.

Overrides:

getColumn in class MatrixObject

Parameters:

j - column index

values - array into which the column is copied

getRow

public void getRow(int i,
                   double[] values)

Copies a row of this matrix into an array of doubles.

Overrides:

getRow in class MatrixObject

Parameters:

i - row index

values - array into which the row is copied

set

public final void set(int i,
                      int j,
                      double value)

Sets a single element of this matrix.

Specified by:

set in class MatrixObject

Parameters:

i - element row index

j - element column index

value - element value

set

public void set(double[] vals)

Sets the elements of this matrix from an array of doubles. The elements in the array should be stored using row-major order, so that element (i,j) is stored at location i*colSize()+j.

Overrides:

set in class MatrixObject

Parameters:

vals - array from which values are copied

setColumn

public void setColumn(int j,
                      double[] values)

Sets a column of this matrix from an array of doubles.

Overrides:

setColumn in class MatrixObject

Parameters:

j - column index

values - array from which column values are copied

setRow

public void setRow(int i,
                   double[] values)

Set a row of this matrix from an array of doubles.

Overrides:

setRow in class MatrixObject

Parameters:

i - row index

values - array from which the row is copied

set

public void set(RigidTransform2d X)

Sets this affine transform to the rigid body transform described by X.

Parameters:

X - rigid body transform to copy

setIdentity

public void setIdentity()

Sets the transformation to the identity.

mul

public void mul(Vector3d vr,
                Vector3d v1)

Multiplies the column vector v1 by this transform and places the result in vr.

Parameters:

vr - result vector

v1 - vector to multiply

mul

public void mul(Vector3d vr)

Multiplies the column vector vr by this transform and places the result back in vr.

Parameters:

vr - vector to multiply (in place)

mulInverse

public boolean mulInverse(Vector3d vr,
                          Vector3d v1)

Multiplies the column vector v1 by the inverse of this transform and places the result in vr.

Parameters:

vr - result vector

v1 - vector to multiply

Returns:

false if this transform is singular

mulInverse

public boolean mulInverse(Vector3d vr)

Multiplies the column vector vr by the inverse of this transform and places the result back in vr.

Parameters:

vr - vector to multiply (in place)

Returns:

false if this transform is singular

invert

public boolean invert()

Inverts this transform in place.

Returns:

false if this transform is singular

epsilonEquals

public boolean epsilonEquals(AffineTransform2dObject X,
                             double epsilon)

Returns true if the elements of this transformation equal those of transform X1within a prescribed tolerance epsilon.

Parameters:

X - transform to compare with

epsilon - comparison tolerance

Returns:

false if the transforms are not equal within the specified tolerance

equals

public boolean equals(AffineTransform2dObject X)

Returns true if the elements of this transformation exactly equal those of transform X1.

Parameters:

X - transform to compare with

Returns:

false if the transforms are not equal