Package com.itextpdf.kernel.geom

Class Matrix

java.lang.Object

com.itextpdf.kernel.geom.Matrix

 public class Matrix extends Object 
      

Keeps all the values of a 3 by 3 matrix and allows you to do some math with matrices.

Field Summary

Fields

Modifier and Type	Field	Description
static final int	I11	the row=1, col=1 position ('a') in the matrix.
static final int	I12	the row=1, col=2 position ('b') in the matrix.
static final int	I13	the row=1, col=3 position (always 0 for 2-D) in the matrix.
static final int	I21	the row=2, col=1 position ('c') in the matrix.
static final int	I22	the row=2, col=2 position ('d') in the matrix.
static final int	I23	the row=2, col=3 position (always 0 for 2-D) in the matrix.
static final int	I31	the row=3, col=1 ('e', or X translation) position in the matrix.
static final int	I32	the row=3, col=2 ('f', or Y translation) position in the matrix.
static final int	I33	the row=3, col=3 position (always 1 for 2-D) in the matrix.

Constructor Summary

Constructors

Constructor	Description
Matrix()	constructs a new Matrix with identity.
Matrix(float tx, float ty)	Constructs a matrix that represents translation.
Matrix(float a, float b, float c, float d, float e, float f)	Creates a Matrix with 6 specified entries.
Matrix(float e11, float e12, float e13, float e21, float e22, float e23, float e31, float e32, float e33)	Creates a Matrix with 9 specified entries.

Method Summary

Modifier and Type	Method	Description
Matrix	add(Matrix arg)	Adds a matrix from this matrix and returns the results.
boolean	equals(Object obj)	Checks equality of matrices.
float	get(int index)	Gets a specific value inside the matrix.
float	getDeterminant()	Computes the determinant of the matrix.
int	hashCode()	Generates a hash code for this object.
Matrix	multiply(Matrix by)	multiplies this matrix by 'b' and returns the result.
Matrix	subtract(Matrix arg)	Subtracts a matrix from this matrix and returns the results.
String	toString()	Generates a String representation of the matrix.

Methods inherited from class java.lang.Object

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

Field Details

I11

 public static final int I11 
            

the row=1, col=1 position ('a') in the matrix.

See Also:

• Constant Field Values

I12

 public static final int I12 
            

the row=1, col=2 position ('b') in the matrix.

See Also:

• Constant Field Values

I13

 public static final int I13 
            

the row=1, col=3 position (always 0 for 2-D) in the matrix.

See Also:

• Constant Field Values

I21

 public static final int I21 
            

the row=2, col=1 position ('c') in the matrix.

See Also:

• Constant Field Values

I22

 public static final int I22 
            

the row=2, col=2 position ('d') in the matrix.

See Also:

• Constant Field Values

I23

 public static final int I23 
            

the row=2, col=3 position (always 0 for 2-D) in the matrix.

See Also:

• Constant Field Values

I31

 public static final int I31 
            

the row=3, col=1 ('e', or X translation) position in the matrix.

See Also:

• Constant Field Values

I32

 public static final int I32 
            

the row=3, col=2 ('f', or Y translation) position in the matrix.

See Also:

• Constant Field Values

I33

 public static final int I33 
            

the row=3, col=3 position (always 1 for 2-D) in the matrix.

See Also:

• Constant Field Values

Constructor Details

Matrix

 public Matrix() 
            

constructs a new Matrix with identity.

Matrix

 public Matrix 
             (float tx, float ty) 
            

Constructs a matrix that represents translation.

Parameters:

tx - x-axis translation

ty - y-axis translation

Matrix

 public Matrix 
             (float e11, float e12, float e13, float e21, float e22, float e23, float e31, float e32, float e33) 
            

Creates a Matrix with 9 specified entries.

Parameters:

e11 - element at position (1,1)

e12 - element at position (1,2)

e13 - element at position (1,3)

e21 - element at position (2,1)

e22 - element at position (2,2)

e23 - element at position (2,3)

e31 - element at position (3,1)

e32 - element at position (3,2)

e33 - element at position (3,3)

Matrix

 public Matrix 
             (float a, float b, float c, float d, float e, float f) 
            

Creates a Matrix with 6 specified entries. The third column will always be [0 0 1] (row, column)

Parameters:

a - element at (1,1)

b - element at (1,2)

c - element at (2,1)

d - element at (2,2)

e - element at (3,1)

f - element at (3,2)

Method Details

get

 public float get 
             (int index) 
            

Gets a specific value inside the matrix.

For reference, the indeces are as follows:
I11 I12 I13
I21 I22 I23
I31 I32 I33

Parameters:

index - an array index corresponding with a value inside the matrix

Returns:

the value at that specific position.

multiply

 public Matrix multiply 
             (Matrix by) 
            

multiplies this matrix by 'b' and returns the result. See http://en.wikipedia.org/wiki/Matrix_multiplication

Parameters:

by - The matrix to multiply by

Returns:

the resulting matrix

add

 public Matrix add 
             (Matrix arg) 
            

Adds a matrix from this matrix and returns the results.

Parameters:

arg - the matrix to subtract from this matrix

Returns:

a Matrix object

subtract

 public Matrix subtract 
             (Matrix arg) 
            

Subtracts a matrix from this matrix and returns the results.

Parameters:

arg - the matrix to subtract from this matrix

Returns:

a Matrix object

getDeterminant

 public float getDeterminant() 
            

Computes the determinant of the matrix.

Returns:

the determinant of the matrix

equals

 public boolean equals 
             (Object obj) 
            

Checks equality of matrices.

Overrides:

equals in class Object

Parameters:

obj - the other Matrix that needs to be compared with this matrix.

Returns:

true if both matrices are equal

See Also:

• Object.equals(java.lang.Object)

hashCode

 public int hashCode() 
            

Generates a hash code for this object.

Overrides:

hashCode in class Object

Returns:

the hash code of this object

See Also:

• Object.hashCode()

toString

 public String toString() 
            

Generates a String representation of the matrix.

Overrides:

toString in class Object

Returns:

the values, delimited with tabs and newlines.

See Also:

• Object.toString()