public class ObjectFactory2D extends PersistentObject
| 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); ... |
| Modifier and Type | Field and Description |
|---|---|
static ObjectFactory2D |
dense
A factory producing dense matrices.
|
static ObjectFactory2D |
sparse
A factory producing sparse matrices.
|
| 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.
|
clonepublic static final ObjectFactory2D dense
public static final ObjectFactory2D sparse
public ObjectMatrix2D appendColumns(ObjectMatrix2D A, ObjectMatrix2D B)
0 1 2
3 4 5
appendColumns
6 7
8 9
-->
0 1 2 6 7
3 4 5 8 9
public ObjectMatrix2D appendRows(ObjectMatrix2D A, ObjectMatrix2D B)
0 1
2 3
4 5
appendRows
6 7
8 9
-->
0 1
2 3
4 5
6 7
8 9
public ObjectMatrix2D compose(ObjectMatrix2D[][] parts)
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].columns != A[2,1].columns (2 != 3) |
IllegalArgumentException - subject to the conditions outlined above.public ObjectMatrix2D composeDiagonal(ObjectMatrix2D A, ObjectMatrix2D B)
A 0
0 B
(The direct sum has A.rows()+B.rows() rows and
A.columns()+B.columns() columns). Cells are copied.public ObjectMatrix2D composeDiagonal(ObjectMatrix2D A, ObjectMatrix2D B, ObjectMatrix2D C)
A 0 0
0 B 0
0 0 C
from the given parts. Cells are copied.public void decompose(ObjectMatrix2D[][] parts, ObjectMatrix2D matrix)
compose(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 | 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
B = 4 x 4 matrix
C = 4 x 3 matrix
D = 2 x 2 matrix |
IllegalArgumentException - subject to the conditions outlined above.public ObjectMatrix2D diagonal(ObjectMatrix1D vector)
5 4 3 -->
5 0 0
0 4 0
0 0 3
public ObjectMatrix1D diagonal(ObjectMatrix2D A)
5 0 0 9
0 4 0 9
0 0 3 9
--> 5 4 3
A - the matrix, need not be square.public ObjectMatrix2D make(Object[][] values)
The values are copied. So subsequent changes in values are not reflected in the matrix, and vice-versa.
values - The values to be filled into the new matrix.IllegalArgumentException - if
for any 1 <= row < values.length: values[row].length != values[row-1].length
.public ObjectMatrix2D make(Object[] values, int rows)
values - One-dimensional array of Objects, packed by columns (ala
Fortran).rows - the number of rows.IllegalArgumentException - values.length must be a multiple of rows
.public ObjectMatrix2D make(int rows, int columns)
public ObjectMatrix2D make(int rows, int columns, Object initialValue)
public ObjectMatrix2D repeat(ObjectMatrix2D A, int rowRepeat, int columnRepeat)
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
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