ObjectFactory2D

java.lang.Object
- cern.colt.PersistentObject
- - cern.colt.matrix.ObjectFactory2D

All Implemented Interfaces:: Serializable, Cloneable

public class ObjectFactory2D
extends PersistentObject

Factory for convenient construction of 2-d matrices holding Object cells. Also provides convenient methods to compose (concatenate) and decompose (split) matrices from/to constituent blocks.

Construction	Use idioms like `ObjectFactory2D.dense.make(4,4)` to construct dense matrices, `ObjectFactory2D.sparse.make(4,4)` to construct sparse matrices.
Construction with initial values	Use other `make` methods to construct matrices with given initial values.
Appending rows and columns	Use methods `appendColumns`, `appendRows` and `repeat` to append rows and columns.
General block matrices	Use methods `compose` and `decompose` to work with general block matrices.
Diagonal block matrices	Use method `composeDiagonal` to work with diagonal block matrices.

If the factory is used frequently it might be useful to streamline the notation. For example by aliasing:

ObjectFactory2D F = ObjectFactory2D.dense;
F.make(4,4);
...

See Also:: Serialized Form

Field Summary

Fields
Modifier and Type Field and Description

static ObjectFactory2D dense
A factory producing dense matrices.

static ObjectFactory2D sparse
A factory producing sparse matrices.
- Fields inherited from class cern.colt.PersistentObject
  serialVersionUID

Fields
Modifier and Type	Field and Description
`static ObjectFactory2D`	`dense` A factory producing dense matrices.
`static ObjectFactory2D`	`sparse` A factory producing sparse matrices.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`ObjectMatrix2D`	`appendColumns(ObjectMatrix2D A, ObjectMatrix2D B)` C = A\|\|B; Constructs a new matrix which is the column-wise concatenation of two other matrices.
`ObjectMatrix2D`	`appendRows(ObjectMatrix2D A, ObjectMatrix2D B)` C = A\|\|B; Constructs a new matrix which is the row-wise concatenation of two other matrices.
`ObjectMatrix2D`	`compose(ObjectMatrix2D[][] parts)` Constructs a block matrix made from the given parts.
`ObjectMatrix2D`	`composeDiagonal(ObjectMatrix2D A, ObjectMatrix2D B)` Constructs a diagonal block matrix from the given parts (the direct sum of two matrices).
`ObjectMatrix2D`	`composeDiagonal(ObjectMatrix2D A, ObjectMatrix2D B, ObjectMatrix2D C)` Constructs a diagonal block matrix from the given parts.
`void`	`decompose(ObjectMatrix2D[][] parts, ObjectMatrix2D matrix)` Splits a block matrix into its constituent blocks; Copies blocks of a matrix into the given parts.
`ObjectMatrix2D`	`diagonal(ObjectMatrix1D vector)` Constructs a new diagonal matrix whose diagonal elements are the elements of `vector`.
`ObjectMatrix1D`	`diagonal(ObjectMatrix2D A)` Constructs a new vector consisting of the diagonal elements of `A`.
`ObjectMatrix2D`	`make(int rows, int columns)` Constructs a matrix with the given shape, each cell initialized with zero.
`ObjectMatrix2D`	`make(int rows, int columns, Object initialValue)` Constructs a matrix with the given shape, each cell initialized with the given value.
`ObjectMatrix2D`	`make(Object[][] values)` Constructs a matrix with the given cell values.
`ObjectMatrix2D`	`make(Object[] values, int rows)` Construct a matrix from a one-dimensional column-major packed array, ala Fortran.
`ObjectMatrix2D`	`repeat(ObjectMatrix2D A, int rowRepeat, int columnRepeat)` C = A\|\|A\|\|..\|\|A; Constructs a new matrix which is duplicated both along the row and column dimension.

Methods inherited from class cern.colt.PersistentObject
clone

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail
- dense
```
public static final ObjectFactory2D dense
```
  A factory producing dense matrices.
- sparse
```
public static final ObjectFactory2D sparse
```
  A factory producing sparse matrices.

Method Detail

appendColumns

public ObjectMatrix2D appendColumns(ObjectMatrix2D A,
                                    ObjectMatrix2D B)

C = A||B; Constructs a new matrix which is the column-wise concatenation of two other matrices.

0 1 2
3 4 5
appendColumns
6 7
8 9
-->
0 1 2 6 7 
3 4 5 8 9

appendRows

public ObjectMatrix2D appendRows(ObjectMatrix2D A,
                                 ObjectMatrix2D B)

C = A||B; Constructs a new matrix which is the row-wise concatenation of two other matrices.

0 1 
2 3 
4 5
appendRows
6 7
8 9
-->
0 1 
2 3 
4 5
6 7
8 9

compose

public ObjectMatrix2D compose(ObjectMatrix2D[][] parts)

Constructs a block matrix made from the given parts. The inverse to method decompose(ObjectMatrix2D[][], ObjectMatrix2D).

All matrices of a given column within parts must have the same number of columns. All matrices of a given row within parts must have the same number of rows. Otherwise an IllegalArgumentException is thrown. Note that nulls within parts[row,col] are an exception to this rule: they are ignored. Cells are copied. Example:

`Code`	`Result`
ObjectMatrix2D[][] parts1 = { { null, make(2,2,1), null }, { make(4,4,2), null, make(4,3,3) }, { null, make(2,2,4), null } }; System.out.println(compose(parts1));	`8 x 9 matrix 0 0 0 0 1 1 0 0 0 0 0 0 0 1 1 0 0 0 2 2 2 2 0 0 3 3 3 2 2 2 2 0 0 3 3 3 2 2 2 2 0 0 3 3 3 2 2 2 2 0 0 3 3 3 0 0 0 0 4 4 0 0 0 0 0 0 0 4 4 0 0 0`
ObjectMatrix2D[][] parts3 = { { identity(3), null, }, { null, identity(3).viewColumnFlip() }, { identity(3).viewRowFlip(), null } }; System.out.println("\n"+make(parts3));	`9 x 6 matrix 1 0 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 0`
ObjectMatrix2D A = ascending(2,2); ObjectMatrix2D B = descending(2,2); ObjectMatrix2D _ = null; ObjectMatrix2D[][] parts4 = { { A, _, A, _ }, { _, A, _, B } }; System.out.println("\n"+make(parts4));	`4 x 8 matrix 1 2 0 0 1 2 0 0 3 4 0 0 3 4 0 0 0 0 1 2 0 0 3 2 0 0 3 4 0 0 1 0`
ObjectMatrix2D[][] parts2 = { { null, make(2,2,1), null }, { make(4,4,2), null, make(4,3,3) }, { null, make(2,3,4), null } }; System.out.println("\n"+Factory2D.make(parts2));	`IllegalArgumentException A[0,1].cols != A[2,1].cols (2 != 3)`

Throws:: IllegalArgumentException - subject to the conditions outlined above.

composeDiagonal
```
public ObjectMatrix2D composeDiagonal(ObjectMatrix2D A,
                                      ObjectMatrix2D B)
```
Constructs a diagonal block matrix from the given parts (the direct sum of two matrices). That is the concatenation
```
A 0
0 B
```
(The direct sum has A.rows()+B.rows() rows and A.columns()+B.columns() columns). Cells are copied.
Returns:

a new matrix which is the direct sum.

composeDiagonal

public ObjectMatrix2D composeDiagonal(ObjectMatrix2D A,
                                      ObjectMatrix2D B,
                                      ObjectMatrix2D C)

Constructs a diagonal block matrix from the given parts. The concatenation has the form

A 0 0
0 B 0
0 0 C

from the given parts. Cells are copied.

decompose

public void decompose(ObjectMatrix2D[][] parts,
                      ObjectMatrix2D matrix)

Splits a block matrix into its constituent blocks; Copies blocks of a matrix into the given parts. The inverse to method compose(ObjectMatrix2D[][]).

Code matrix --> parts

ObjectMatrix2D matrix = ... ;
ObjectMatrix2D _ = null;
ObjectMatrix2D A,B,C,D;
A = make(2,2); B = make (4,4);
C = make(4,3); D = make (2,2);
ObjectMatrix2D[][] parts = 
{
   { _, A, _ },
   { B, _, C },
   { _, D, _ }
};
decompose(parts,matrix);
System.out.println("\nA = "+A);
System.out.println("\nB = "+B);
System.out.println("\nC = "+C);
System.out.println("\nD = "+D);

8 x 9 matrix 9 9 9 9 1 1 9 9 9 9 9 9 9 1 1 9 9 9 2 2 2 2 9 9 3 3 3 2 2 2 2 9 9 3 3 3 2 2 2 2 9 9 3 3 3 2 2 2 2 9 9 3 3 3 9 9 9 9 4 4 9 9 9 9 9 9 9 4 4 9 9 9

A = 2 x 2 matrix 1 1 1 1

B = 4 x 4 matrix 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2

C = 4 x 3 matrix 3 3 3 3 3 33 3 33 3 3

D = 2 x 2 matrix 4 4 4 4

Throws:: IllegalArgumentException - subject to the conditions outlined above.

diagonal
```
public ObjectMatrix2D diagonal(ObjectMatrix1D vector)
```
Constructs a new diagonal matrix whose diagonal elements are the elements of vector. Cells values are copied. The new matrix is not a view. Example:
```
5 4 3 -->
5 0 0
0 4 0
0 0 3
```
Returns:

a new matrix.

diagonal
```
public ObjectMatrix1D diagonal(ObjectMatrix2D A)
```
Constructs a new vector consisting of the diagonal elements of A. Cells values are copied. The new vector is not a view. Example:
```
5 0 0 9
0 4 0 9
0 0 3 9
--> 5 4 3
```
Parameters:

A - the matrix, need not be square.

Returns:

a new vector.

make
```
public ObjectMatrix2D make(Object[][] values)
```
Constructs a matrix with the given cell values. values is required to have the form values[row][column] and have exactly the same number of columns in every row.
The values are copied. So subsequent changes in values are not reflected in the matrix, and vice-versa.

Parameters:

values - The values to be filled into the new matrix.

Throws:

IllegalArgumentException - if for any 1 <= row < values.length: values[row].length != values[row-1].length.

make
```
public ObjectMatrix2D make(Object[] values,
                           int rows)
```
Construct a matrix from a one-dimensional column-major packed array, ala Fortran. Has the form matrix.get(row,column) == values[row + column*rows]. The values are copied.

Parameters:

values - One-dimensional array of Objects, packed by columns (ala Fortran).

rows - the number of rows.

Throws:

IllegalArgumentException - values.length must be a multiple of rows.

make

public ObjectMatrix2D make(int rows,
                           int columns)

Constructs a matrix with the given shape, each cell initialized with zero.

make

public ObjectMatrix2D make(int rows,
                           int columns,
                           Object initialValue)

Constructs a matrix with the given shape, each cell initialized with the given value.

repeat

public ObjectMatrix2D repeat(ObjectMatrix2D A,
                             int rowRepeat,
                             int columnRepeat)

C = A||A||..||A; Constructs a new matrix which is duplicated both along the row and column dimension. Example:

0 1
2 3
repeat(2,3) -->
0 1 0 1 0 1
2 3 2 3 2 3
0 1 0 1 0 1
2 3 2 3 2 3

Class ObjectFactory2D

Field Summary

Fields inherited from class cern.colt.PersistentObject

Method Summary

Methods inherited from class cern.colt.PersistentObject

Methods inherited from class java.lang.Object

Field Detail

dense

sparse

Method Detail

appendColumns

appendRows

compose

composeDiagonal

composeDiagonal

decompose

diagonal

diagonal

make

make

make

make

repeat