net.algart.arrays
Interface Matrix<T extends Array>

All Superinterfaces:

java.lang.Cloneable

All Known Implementing Classes:

AbstractMatrix

public interface Matrix<T extends Array>
extends java.lang.Cloneable

AlgART matrix: multidimensional array.

Unlike AlgART array, AlgART matrix is a very simple thing. The matrix is just a pair:

1. a reference to any AlgART array, that stores all matrix elements;
2. the set of dimensions: a little usual array of integers — long[] dim, describing the sizes of the multidimensional matrix in every dimension.

The product of all dimensions must be equal to the array length. Moreover, the array must be unresizable: so, the array length cannot be changed after creating the matrix.

It is supposed that all matrix elements are stored in the AlgART array. The storing scheme is traditional. For 2D matrix, the matrix element (x,y) is stored at the position y*dim[0]+x of the array (dim[0] is the first matrix dimension: the "width"). For 3D matrix, the matrix element (x,y,z) is stored at the position z*dim[1]*dim[0]+y*dim[0]+x (dim[0] is the x-dimension, dim[1] is the y-dimension). In the common case, the element of n-dimensional matrix with coordinates i₀,i₁,...,i_n-1 is stored at the position

i_n-1d_n-2...d₁d₀ + ... + i₂d₁d₀ + i₁d₀ + i₀,

where d_k=dim[k] (k=0,1,...,n-1) is the dimension #k.

There are 3 basic ways to create a new matrix.

1. You may create a new zero-filled matrix with new allocated array by MemoryModel.newMatrix(Class, Class, long...) method or one of more concrete methods MemoryModel.newByteMatrix(long...), MemoryModel.newShortMatrix(long...), etc.
2. You may create a matrix view of an existing array with the specified dimension set by Matrices.matrix(Array, long...) method.
3. You may replace built-in array of the matrix with a new one (with the same length) by matrix(Array) method of the matrix instance; the new matrix instance will be created. It is the basic way to change some properties of the built-in array, for example, to convert it to immutable or copy-on-next-write form.

We do not provide special tools for accessing matrix elements by several indexes, as "getByte(x,y)" or similar methods. But there is the index method, that transforms a set of multidimensional indexes i₀, i₂, ..., i_n-1 into the position in the corresponded array, as described above. Also you can get a reference to the built-in array by the array() method. The typical example of access to matrix elements is the following:

 Matrix<UpdatableFloatArray> m = ...;
 m.array().setFloat(m.index(x, y, z), myValue);
 

There are two important notes concerning usage of matrices.

First, the matrix indexes in all methods (index, dim(n), dim argument in MemoryModel.newMatrix, etc.) are ordered from the lowest index to the highest. Please compare: for numeric matrix m, m.array().getDouble(m.index(15,10)) returns the element #15 of the row #10. However, for usual 2-dimentional Java array, declared as "double[][] a", the same element is accessed as a[10][15]!

Second, the number of indexes in the index method may differ from the number of dimensions (dimCount()). In any case, the returned position in calculated by the formula listed above (i_n-1d_n-2...d₁d₀ + ... + i₂d₁d₀ + i₁d₀ + i₀), where i₀, i₂, ..., i_n-1 are the coordinates passed to the method, and d_k is the dimension #k or 1 if k>=dimCount().

The matrix object is immutable, that means that there are no ways to change any dimension or the reference to the built-in AlgART array. But the matrix elements can be modified, if the AlgART array is not immutable. So, the matrix object is thread-safe or thread-compatible in the same situation as the built-in AlgART array: see comments to Array interface.

The generic argument T specifies the type of the built-in AlgART array. Any array type can be declared here, but the contract of this interface requires that the array must be unresizable. So, there are no ways to create a matrix with MutableArray (or its subinterface) as the type argument, alike Matrix<MutableByteArray>: all creation methods throw IllegalArgumentException in this case.

AlgART Laboratory 2007-2010

Since:

JDK 1.5

Version:

1.2

Author:

Daniel Alievsky

See Also:

Array, UpdatableArray, MutableArray

MAX_DIM_COUNT_FOR_SOME_ALGORITHMS

static final int MAX_DIM_COUNT_FOR_SOME_ALGORITHMS

Maximal number of dimensions for some complex algorithms or service classes: 9. Most modules process matrices with any number of dimensions, but there are some cases when an algorithm can work only with 2-dimensional, 3-dimensional or n-dimensional matrices with n<=MAX_DIM_COUNT_FOR_SOME_ALGORITHMS. In this package and all known subpackages of net.algart package, the following classes require that the number of dimensions must not be greater than MAX_DIM_COUNT_FOR_SOME_ALGORITHMS:

• net.algart.matrices.bitscanning.ConnectedObjectScanner;
• MatrixInfo.

Note: the value of this constant (9) is the maximal n so that 3ⁿ<32768=2¹⁵ (3⁹=19683). It can be useful while storing indexes of elements of little 3x3x3x... submatrix (aperture): signed short type is enough in this case.

See Also:

Constant Field Values

array

T array()

Returns a reference to the built-in AlgART array.

There is a guarantee that this method works very quickly (usually it just returns a value of some private field).

Returns:

a reference to the built-in AlgART array.

elementType

java.lang.Class<?> elementType()

Equivalent to array().elementType().

Returns:

the type of the matrix elements.

size

long size()

Equivalent to array().length().

Returns:

the total number of matrix elements.

type

java.lang.Class<? extends Array> type()

Returns array().type().

Returns:

the canonical type of AlgART array of the same kind as the built-in one.

Throws:

java.lang.NullPointerException - if the passed argument is null.

updatableType

java.lang.Class<? extends UpdatableArray> updatableType()

Returns array().updatableType().

Returns:

the canonical updatable type of AlgART array of the same kind as the built-in one.

Throws:

java.lang.NullPointerException - if the passed argument is null.

type

<U extends Array> java.lang.Class<? extends U> type(java.lang.Class<U> arraySupertype)

Returns array().type(), if it is subtype of (or same type as) the passed arraySupertype, or throws ClassCastException in other case. (If the passed argument is a class of UpdatableArray or some its subinterfaces or subclasses, IllegalArgumentException is thrown instead: updatable array classes cannot be specified in this method.)

Parameters:

arraySupertype - the required supertype of the built-in AlgART array.

Returns:

the canonical type of AlgART array of the same kind as the built-in one.

Throws:

java.lang.NullPointerException - if the passed argument is null.

java.lang.IllegalArgumentException - if the passed argument is a class of UpdatableArray or some its subinterfaces or subclasses (updatable classes cannot be supertypes of for Array.type()).

java.lang.ClassCastException - if arraySupertype does not allow storing the immutable version of the built-in AlgART array.

updatableType

<U extends Array> java.lang.Class<? extends U> updatableType(java.lang.Class<U> arraySupertype)

Returns array().updatableType(), if it is subtype of (or same type as) the passed arraySupertype, or throws ClassCastException in other case.

Parameters:

arraySupertype - the required supertype of the built-in AlgART array.

Returns:

the canonical updatable type of AlgART array of the same kind as the built-in one.

Throws:

java.lang.NullPointerException - if the passed argument is null.

java.lang.ClassCastException - if arraySupertype does not allow storing the built-in AlgART array.

dimensions

long[] dimensions()

Returns an array containing all dimensions of this matrix. Returned array is equal to the dim argument passed to methods that create new matrix instances.

The returned array is a clone of the internal dimension array stored in this object. The returned array is never empty (its length cannot be zero). The elements of the returned array are never negative.

Returns:

an array containing all dimensions of this matrix.

dimCount

int dimCount()

Returns the number of dimensions of this matrix. Equivalent to dimensions().length, but works faster.

There is a guarantee that this method works very quickly (usually it just returns a value of some private field).

Returns:

the number of dimensions of this matrix.

dim

long dim(int n)

Returns the dimension #n of this matrix or 1 if n>=dimCount(). Equivalent to n<dimCount()?dimensions()[n]:1, but works faster.

There is a guarantee that this method works very quickly.

Parameters:

n - the index of dimension.

Returns:

the dimension #n of this matrix.

Throws:

java.lang.IndexOutOfBoundsException - if n<0 (but not if n is too large).

dimX

long dimX()

Equivalent to dim(0).

Returns:

the first matrix dimension.

dimY

long dimY()

Equivalent to dim(1).

Returns:

the second matrix dimension.

dimZ

long dimZ()

Equivalent to dim(2).

Returns:

the third matrix dimension.

dimEquals

boolean dimEquals(Matrix<?> m)

Indicates whether the other matrix has the same dimension array. In other words, returns true if and only if both matrices have the same dimension count (dimCount()) and the corresponding dimensions (dim(k)) are equal.

Parameters:

m - the matrix to be compared for equal dimensions with this matrix.

Returns:

true if the specified matrix has the same dimension array.

Throws:

java.lang.NullPointerException - if the passed argument is null.

dimEquals

boolean dimEquals(long... dimensions)

Indicates whether the passed dimensions are equal to the dimension array of this matrix. In other words, returns true if and only if dimension.length==dimCount() and the corresponding dimensions dim(k)==dimension[k] for all k.

Note: this method does not check, whether all passed dimensions are correct (in particular, non-negative). If some elements of the passed array are incorrect, this method just returns false. But it the passed array is null, this method throws NullPointerException.

Parameters:

dimensions - the dimension array.

Returns:

true if the specified dimensions are equal to the dimensions of this matrix.

Throws:

java.lang.NullPointerException - if the passed argument is null.

index

long index(long... coordinates)

Returns the linear index in the built-in AlgART array of the matrix element with specified coordinates. More precisely, index(i₀,i₁,...,i_n-1) returns the following value:

i_n-1d_n-2...d₁d₀ + ... + i₂d₁d₀ + i₁d₀ + i₀,

where d_k=dim(k). All passed indexes i_k must be in ranges 0..d_k-1.

All elements of coordinates array are always used, regardless of the number of matrix dimensions. But the extra elements of coordinates array must be zero, because d_k=1 for k>=dimCount().

Good algorithms processing the matrix should use this method rarely: usually there are more optimal ways to calculate necessary linear index. For example, if you just need to calculate something for all matrix elements, the best way is the following:

 Array a = m.array();
 for (long disp = 0, n = a.length(); disp < n; disp++)
     // process the element #k of the array
 

Parameters:

coordinates - all coordinates.

Returns:

the linear index of the matrix element with specified coordinates.

Throws:

java.lang.NullPointerException - if the passed array is null.

java.lang.IllegalArgumentException - if the passed array is empty (no coordinates are passed).

java.lang.IndexOutOfBoundsException - if some coordinate i_k is out of range 0..d_k-1.

See Also:

cyclicIndex(long...), coordinates(long, long[])

index

long index(long x,
           long y)

The simplified version of the full index method for the case of 2-dimensional matrix.

Parameters:

x - the first coordinate.

y - the second coordinate.

Returns:

y * dimX() + x.

Throws:

java.lang.IndexOutOfBoundsException - if x<0, x>=dimX(), y<0 or y>=dimX().

index

long index(long x,
           long y,
           long z)

The simplified version of the full index method for the case of 3-dimensional matrix.

Parameters:

x - the first coordinate.

y - the second coordinate.

z - the third coordinate.

Returns:

z * dimY() * dimX() + y * dimX() + x.

Throws:

java.lang.IndexOutOfBoundsException - if x<0, x>=dimX(), y<0, y>=dimX(), z<0 or z>=dimZ().

coordinates

long[] coordinates(long index,
                   long[] result)

Returns the coordinates in the matrix, corresponding to the given linear index in the built-in AlgART array. This method is reverse to index(long...): for any index, index(coordinates(index, null)) == index.

The result argument may be null or some array, containing at least dimCount() elements. If the first case, this method allocates new Java array long[dimCount()] for storing coordinates and returns it. In the second case, this method stores the found coordinates in result array and returns it.

Parameters:

index - the linear index in the built-in AlgART array.

result - the array where you want to store results; may be null.

Returns:

a reference to the result argument, if it is not null, else newly created Java array containg all calculated coordinates.

Throws:

java.lang.IllegalArgumentException - if result!=null, but result.length<dimCount().

java.lang.IndexOutOfBoundsException - if index<0 or index>=dim(0)*dim(1)*...=array().length().

uncheckedIndex

long uncheckedIndex(long... coordinates)

An analog of index(long...) method, that does not check, whether the passed coordinates are in the required ranges. More precisely, uncheckedIndex(i₀,i₁,...,i_n-1) always returns the following value:

i_n-1d_n-2...d₁d₀ + ... + i₂d₁d₀ + i₁d₀ + i₀,

where d_k=dim(k).

All calculations are performed with long type without any overflow checks. All elements of coordinates array are always used, regardless of the number of matrix dimensions. Please remember that d_k=dim(k)=1 for k>=dimCount() (extra elements of coordinates array)..

Parameters:

coordinates - all coordinates.

Returns:

the linear index of the matrix element with specified coordinates, without range checks.

Throws:

java.lang.NullPointerException - if the passed array is null.

java.lang.IllegalArgumentException - if the passed array is empty (no coordinates are passed).

cyclicIndex

long cyclicIndex(long... coordinates)

An analog of index(long...) method, that does not check, whether the passed coordinates are in the required ranges, and also replaces the resulting shift by the positive remainder from division of it by the length of the built-in array. More precisely, let i₀,i₁,...,i_n-1 are the arguments of the method, and index is the following value (as in index(long...) method):

index = i_n-1d_n-2...d₁d₀ + ... + i₂d₁d₀ + i₁d₀ + i₀,

where d_k=dim(k). Here we do no require that the passed indexes i_k are in ranges 0..d_k-1. Then, let len=array().length()=d_n-1...d₁d₀. The result of this method is the following:

index >= 0 ? index % len : index % len + len

(It is in the 0..len-1 range always.) In other words, the resulting index is "pseudo-cyclical", as the resulting shift in Matrices.asShifted(MemoryModel, Matrix, long...) method.

All calculations are performed with long type without any overflow checks. All elements of coordinates array are always used, regardless of the number of matrix dimensions. (You may note that extra elements of coordinates array are ignored in fact: they add k*len summand, where k is an integer.)

Parameters:

coordinates - all coordinates.

Returns:

the pseudo-cyclical linear index of the matrix element with specified coordinates, without range checks.

Throws:

java.lang.NullPointerException - if the passed array is null.

java.lang.IllegalArgumentException - if the passed array is empty (no coordinates are passed).

inside

boolean inside(long... coordinates)

Returns true if all specified coordinates i_k are inside the ranges 0..d_k-1.

This method allows simply check that the arguments of the index method are correct and will not lead to IndexOutOfBoundsException:

 if (matrix.inside(i1, i2, ...)) {
     long index = matrix.index(i1, i2, ...);
     // processing an element at this index
 } else {
     // special branche for positions outside the matrix
 }
 

Parameters:

coordinates - all coordinates.

Returns:

true if all specified coordinates are inside the matrix.

Throws:

java.lang.NullPointerException - if the passed array is null.

java.lang.IllegalArgumentException - if the passed array is empty (no coordinates are passed).

inside

boolean inside(long x,
               long y)

The simplified version of the full index method for the case of 2-dimensional matrix.

Parameters:

x - the first coordinate.

y - the second coordinate.

Returns:

tt>true if all specified coordinates are inside the matrix.

inside

boolean inside(long x,
               long y,
               long z)

The simplified version of the full index method for the case of 3-dimensional matrix.

Parameters:

x - the first coordinate.

y - the second coordinate.

z - the third coordinate.

Returns:

tt>true if all specified coordinates are inside the matrix.

matrix

<U extends Array> Matrix<U> matrix(U anotherArray)

Returns the new matrix backed by the specified AlgART array with the same dimensions as this one. Equivalent to Matrices.matrix(anotherArray, dimensions()).

The array anotherArray must be unresizable, and its length must be equal to the length of the array built-in this matrix.

Parameters:

anotherArray - some another AlgART array with the same length as array().

Returns:

new matrix instance.

Throws:

java.lang.NullPointerException - if anotherArray argument is null.

java.lang.IllegalArgumentException - if the passed array is resizable (for example, implements MutableArray).

SizeMismatchException - if the product of all dimensions is not equal to the passed array length.

cast

<U extends Array> Matrix<U> cast(java.lang.Class<U> arrayClass)

Returns this matrix, cast to the specified generic array type, or throws ClassCastException if the built-in AlgART array cannot be cast to the required type (because the array type is not its subclass). Works alike matrix((U)array), but returns the reference to this instance (and, so, preserves the "fresh status") and is compiled without "unchecked cast" warning.

This method is useful when you need to cast the type of AlgART array, built in this matrix, to to its sub- or superinterface.

Parameters:

arrayClass - the type of built-in array in the new matrix.

Returns:

new matrix with the same dimensions, based on the same array cast to the required type.

Throws:

java.lang.NullPointerException - if the argument is null.

java.lang.ClassCastException - if the built-in AlgART array cannot be cast to the required type.

subMatrix

Matrix<T> subMatrix(long[] from,
                    long[] to)

Returns a view of the rectangular fragment of this matrix between from, inclusive, and to, exclusive. More precisely, the returned matrix consists of all elements of this one with coordinates i₀, i₁, ..., i_n−1, n=dimCount(), matching the following conditions:

     from[0] <= i0 < to[0],
     from[1] <= i1 < to[1],
     . . .
     from[n-1] <= in-1 < to[n-1]
 

So, every dimension dim(k) in the returned matrix will be equal to to[k]-from[k]. The following condition must be fulfilled for all k: 0<=from[k]<=to[k]<=thisMatrix.dim(k). The element type of the returned matrix is identical to the element type of this matrix.

The built-in AlgART array of the returned matrix is backed by the built-in array of this matrix, so — if this matrix is not immutable — any changes of the elements of the returned matrix are reflected in this matrix, and vice-versa. The returned matrix is immutable if, and only if, the built-in array of this matrix does not implement UpdatableArray. The Array.asTrustedImmutable() method in the built-in array of the returned matrix is equivalent to Array.asImmutable(), and Array.asCopyOnNextWrite() method just returns the full copy of the array.

In the built-in array of the returned matrix, the following methods: newCompatibleEmptyArray(), newCompatibleEmptyArray(Class elementType), newCompatibleArray(long initialLength), newCompatibleArray(Class elementType, long initialLength), newCompatibleUnresizableArray(long length), newCompatibleUnresizableArray(Class elementType, long length) are based on the calls of the corresponding newCompatible... method of the built-in array of this matrix. It is the reason why this method does not use MemoryModel argument, unlike, for example, Arrays.asShifted(MemoryModel, Array, long).

Parameters:

from - low endpoints (inclusive) of all coordinates.

to - high endpoints (exclusive) of all coordinates.

Returns:

a view of the specified rectangular fragment within this matrix.

Throws:

java.lang.NullPointerException - if from or to argument is null.

java.lang.IllegalArgumentException - if from.length or to.length is not equal to dimCount().

java.lang.IndexOutOfBoundsException - if, for some k, from[k]<0 || to[k]>dim(k) || from[k]>to[k].

See Also:

subMatrix(long[], long[], Object), subMatrix(long...), subMatrix(IRectangularArea), subMatr(long[], long[], Object), subMatr(long[], long[]), isSubMatrix()

subMatrix

Matrix<T> subMatrix(IRectangularArea area)

Equivalent to subMatrix(long[] from, long[] to) method, where from.length=to.length=area.coordCount(), from[k]=area.min(k)}, to[k]=area.max(k)}+1.

Parameters:

area - rectangular area within this matrix.

Returns:

a view of the specified rectangular fragment within this matrix.

Throws:

java.lang.NullPointerException - if the argument is null.

java.lang.IllegalArgumentException - if area.coordCount() is not equal to dimCount().

java.lang.IndexOutOfBoundsException - if, for some k, min[k]<0 || max[k]>=dim(k), where min=area.min().coordinates() and, max=area.max().coordinates().

subMatrix

Matrix<T> subMatrix(long... fromAndTo)

Equivalent to subMatrix(long[] from, long[] to) method, where from is the first half of fromAndTo array and to is it's second half. (In other words, from[k]=fromAndTo[k] and to[k]=fromAndTo[k+fromAndTo.length/2].) The length of fromAndTo array must be equal to 2*dimCount().

Parameters:

fromAndTo - low endpoints (inclusive) and then high endpoints (exclusive) of all coordinates.

Returns:

a view of the specified rectangular fragment within this matrix.

Throws:

java.lang.NullPointerException - if fromAndTo argument is null.

java.lang.IllegalArgumentException - if fromAndTo.length is not equal to 2*dimCount().

java.lang.IndexOutOfBoundsException - in the same situations as in subMatrix(long[], long[]).

subMatrix

Matrix<T> subMatrix(long[] from,
                    long[] to,
                    java.lang.Object outsideValue)

An extended analog of subMatrix(long[], long[]) method, allowing to get a rectangular fragment which is not fully inside this matrix. More precisely, unlike that method, here the only requirement for the from and to coordinate boundaries is from[k]<=to[k], but from[k] may be negative and to[k] may be greater than dim(k). The elements of the returned matrix, that do not correspond to any elements of this one (i.e. "lie outside" of this matrix), are considered to be equal outsideValue: any attempt to read them returns this value. Attempts to write to such elements of the returned matrix are just ignored.

For non-primitive element types, the outsideValue argument must be some instance of the class elementType(), or its superclass, or null. For primitive element types, outsideValue may be null or any wrapper for primitive types: Boolean, Byte, etc. In this case, it is automatically cast to the required element type (while reading elements) according the following rules:

• null is converted to false for bit elements or to zero (0, (char)0, 0.0) for all other element types;
• if the wrapper type corresponds to the element primitive type, the trivial default conversion is used; in all other cases:
• Boolean value v is converted to v?1:0 for numeric element types and to v?(char)1:(char)0 for char element type;
• Character value v is converted to (byte)v, (short)v, (int)v, (long)v, (float)v, (double)v for corresponding numeric element types and to v!=0 for boolean element type;
• Byte value v is converted to (char)(v&0xFF), (short)(v&0xFF), (int)(v&0xFF), (long)(v&0xFF), (float)(v&0xFF), (double)(v&0xFF) for corresponding numeric or character element types and to v!=0 for boolean element type;
• Short value v is converted to (char)v, (byte)v, (int)(v&0xFFFF), (long)(v&0xFFFF), (float)(v&0xFFFF), (double)(v&0xFFFF) for corresponding numeric or character element types and to v!=0 for boolean element type;
• Integer, Long, Float or Double value v is converted to (char)v, (byte)v, (short)v, (int)v, (long)v, (float)v, (double)v for corresponding numeric or character element types and to v!=0 for boolean element type.

Parameters:

from - low endpoints (inclusive) of all coordinates.

to - high endpoints (exclusive) of all coordinates.

outsideValue - the value returned while reading elements, lying outside this matrix.

Returns:

a view of the specified rectangular fragment within this matrix.

Throws:

java.lang.NullPointerException - if from or to argument is null.

java.lang.IllegalArgumentException - if from.length or to.length is not equal to dimCount(), or if the product of all differences to[k]-from[k] (i.e. desired total size of the new matrix) is greater than Long.MAX_VALUE.

java.lang.IndexOutOfBoundsException - if, for some k, from[k]>to[k] or to[k]-from[k]>Long.MAX_VALUE.

java.lang.ClassCastException - if outsideValue is not null and its class is illegal, i.e. cannot be casted to the necessary type according the rules specified above.

See Also:

subMatr(long[], long[], Object), subMatr(long[], long[]), isSubMatrix()

subMatrix

Matrix<T> subMatrix(IRectangularArea area,
                    java.lang.Object outsideValue)

Equivalent to subMatrix(long[] from, long[] to, Object outsideValue) method, where from.length=to.length=area.coordCount(), from[k]=area.min(k)}, to[k]=area.max(k)}+1.

Parameters:

area - rectangular area within this matrix.

outsideValue - the value returned while reading elements, lying outside this matrix.

Returns:

a view of the specified rectangular fragment within this matrix.

Throws:

java.lang.NullPointerException - if the argument is null.

java.lang.IllegalArgumentException - if area.coordCount() is not equal to dimCount(), or if the product of all area.IRectangularArea.sizes() (i.e. desired total size of the new matrix) is greater than Long.MAX_VALUE.

subMatrix

Matrix<T> subMatrix(long fromX,
                    long fromY,
                    long toX,
                    long toY,
                    java.lang.Object outsideValue)

Equivalent to subMatrix(new long[]{fromX,fromY}, new long[]{toX,toY}, outsideValue). Note that this matrix must be 2-dimensional (in other case IllegalArgumentException will be thrown).

Parameters:

fromX - low endpoints (inclusive) of the first coordinate.

fromY - low endpoints (inclusive) of the second coordinate.

toX - high endpoints (exclusive) of the first coordinate.

toY - high endpoints (exclusive) of the second coordinate.

outsideValue - the value returned while reading elements, lying outside this matrix.

Returns:

a view of the specified rectangular fragment within this matrix.

Throws:

java.lang.IllegalArgumentException - if dimCount()!=2 or if the product (toX-fromX)*(toY-fromY) (i.e. desired total size of the new matrix) is greater than Long.MAX_VALUE.

java.lang.IndexOutOfBoundsException - if fromX>toX or toX-fromX>Long.MAX_VALUE, or if fromY>toY or toY-fromY>Long.MAX_VALUE.

java.lang.ClassCastException - if outsideValue is not null and its class is illegal, i.e. cannot be casted to the necessary type according the rules specified above.

subMatrix

Matrix<T> subMatrix(long fromX,
                    long fromY,
                    long fromZ,
                    long toX,
                    long toY,
                    long toZ,
                    java.lang.Object outsideValue)

Equivalent to subMatrix(new long[]{fromX,fromY,fromZ}, new long[]{toX,toY,toZ}, outsideValue). Note that this matrix must be 3-dimensional (in other case IllegalArgumentException will be thrown).

Parameters:

fromX - low endpoints (inclusive) of the first coordinate.

fromY - low endpoints (inclusive) of the second coordinate.

fromZ - low endpoints (inclusive) of the third coordinate.

toX - high endpoints (exclusive) of the first coordinate.

toY - high endpoints (exclusive) of the second coordinate.

toZ - high endpoints (exclusive) of the third coordinate.

outsideValue - the value returned while reading elements, lying outside this matrix.

Returns:

a view of the specified rectangular fragment within this matrix.

Throws:

java.lang.IllegalArgumentException - if dimCount()!=3 or if the product (toX-fromX)*(toY-fromY)*(toZ-fromZ) (i.e. desired total size of the new matrix) is greater than Long.MAX_VALUE.

java.lang.IndexOutOfBoundsException - if fromX>toX or toX-fromX>Long.MAX_VALUE, or if fromY>toY or toY-fromY>Long.MAX_VALUE, or if fromZ>toZ or toZ-fromZ>Long.MAX_VALUE.

java.lang.ClassCastException - if outsideValue is not null and its class is illegal, i.e. cannot be casted to the necessary type according the rules specified above.

subMatr

Matrix<T> subMatr(long[] position,
                  long[] dimensions)

Equivalent to subMatrix(long[] from, long[] to) method, where from[k]=position[k] and to[k]=position[k]+dimensions[k] for all k.

This method is convenient for copying rectangular fragment of one matrix to another, for example:

 Matrix<? extends Array> srcSm = src.subMatr(srcPos, dim);
 Matrix<? extends UpdatableArray> destSm = dest.subMatr(destPos, dim);
 Matrices.copy(someContext, destSm, srcSm);
 

Parameters:

position - low endpoints (inclusive) of all coordinates.

dimensions - dimensions of the returned submatrix.

Returns:

a view of the specified rectangular fragment within this matrix.

Throws:

java.lang.NullPointerException - if position or dimensions argument is null.

java.lang.IllegalArgumentException - if position.length or dimensions.length is not equal to dimCount().

java.lang.IndexOutOfBoundsException - if, for some k, position[k]<0 || dimensions[k]<0 || position[k]+dimensions[k]>dim(k).

See Also:

subMatr(long[], long[], Object), subMatr(long...)

subMatr

Matrix<T> subMatr(long... positionAndDimensions)

Equivalent to subMatr(long[] position, long[] dimensions) method, where position is the first half of positionAndDimensions array and dimensions is it's second half. (In other words, position[k]=positionAndDimensions[k] and dimensions[k]=positionAndDimensions[k+positionAndDimensions.length/2].) The length of positionAndDimensions array must be equal to 2*dimCount().

Parameters:

positionAndDimensions - low endpoints (inclusive) of all coordinates and then dimensions of the result.

Returns:

a view of the specified rectangular fragment within this matrix.

Throws:

java.lang.NullPointerException - if positionAndDimensions argument is null.

java.lang.IllegalArgumentException - if positionAndDimensions.length is not equal to 2*dimCount().

java.lang.IndexOutOfBoundsException - in the same situations as in subMatr(long[], long[]).

subMatr

Matrix<T> subMatr(long[] position,
                  long[] dimensions,
                  java.lang.Object outsideValue)

Equivalent to subMatrix(long[] from, long[] to, Object outsideValue) method, where from[k]=position[k] and to[k]=position[k]+dimensions[k] for all k.

Parameters:

position - low endpoints (inclusive) of all coordinates.

dimensions - dimensions of the returned submatrix.

outsideValue - the value returned while reading elements, lying outside this matrix.

Returns:

a view of the specified rectangular fragment within this matrix.

Throws:

java.lang.NullPointerException - if position or dimensions argument is null.

java.lang.IllegalArgumentException - if position.length or dimensions.length is not equal to dimCount(), or if the product of all dimensions[k] (i.e. desired total size of the new matrix) is greater than Long.MAX_VALUE.

java.lang.IndexOutOfBoundsException - if, for some k, dimensions[k]<0 or position[k]+dimensions[k]>Long.MAX_VALUE.

java.lang.ClassCastException - if outsideValue is not null and its class is illegal, i.e. cannot be casted to the necessary type according the rules specified for subMatrix(long[], long[], Object) method.

See Also:

subMatr(long[], long[])

subMatr

Matrix<T> subMatr(long x,
                  long y,
                  long dimX,
                  long dimY,
                  java.lang.Object outsideValue)

Equivalent to subMatr(new long[]{x,y}, new long[]{dimX,dimY}, outsideValue). Note that this matrix must be 2-dimensional (in other case IllegalArgumentException will be thrown).

Parameters:

x - low endpoint (inclusive) of the first coordinate.

y - low endpoint (inclusive) of the second coordinate.

dimX - th first dimension of the returned submatrix.

dimY - the second dimension of the returned submatrix.

outsideValue - the value returned while reading elements, lying outside this matrix.

Returns:

a view of the specified rectangular fragment within this matrix.

Throws:

java.lang.IllegalArgumentException - if dimCount()!=2, or if the product dimX*dimY (i.e. desired total size of the new matrix) is greater than Long.MAX_VALUE.

java.lang.IndexOutOfBoundsException - if dimX<0, dimY<0, x+dimX>Long.MAX_VALUE or y+dimY>Long.MAX_VALUE.

java.lang.ClassCastException - if outsideValue is not null and its class is illegal, i.e. cannot be casted to the necessary type according the rules specified for subMatrix(long[], long[], Object) method.

subMatr

Matrix<T> subMatr(long x,
                  long y,
                  long z,
                  long dimX,
                  long dimY,
                  long dimZ,
                  java.lang.Object outsideValue)

Equivalent to subMatr(new long[]{x,y,z}, new long[]{dimX,dimY,dimZ}, outsideValue). Note that this matrix must be 3-dimensional (in other case IllegalArgumentException will be thrown).

Parameters:

x - low endpoint (inclusive) of the first coordinate.

y - low endpoint (inclusive) of the second coordinate.

z - low endpoint (inclusive) of the third coordinate.

dimX - th first dimension of the returned submatrix.

dimY - the second dimension of the returned submatrix.

dimZ - the third dimension of the returned submatrix.

outsideValue - the value returned while reading elements, lying outside this matrix.

Returns:

a view of the specified rectangular fragment within this matrix.

Throws:

java.lang.IllegalArgumentException - if dimCount()!=3, or if the product dimX*dimY*dimZ (i.e. desired total size of the new matrix) is greater than Long.MAX_VALUE.

java.lang.IndexOutOfBoundsException - if dimX<0, dimY<0, dimZ<0, x+dimX>Long.MAX_VALUE, y+dimY>Long.MAX_VALUE or z+dimZ>Long.MAX_VALUE.

java.lang.ClassCastException - if outsideValue is not null and its class is illegal, i.e. cannot be casted to the necessary type according the rules specified for subMatrix(long[], long[], Object) method.

subMatrixParent

Matrix<T> subMatrixParent()

If this matrix is a submatrix of some parent matrix, created by one of calls parent.subMatrix(...) or parent.subMatr(...), returns a reference to the parent matrix instance. If this matrix is not a submatrix, throws UnsupportedOperationException.

Returns:

a reference to the parent matrix, if this instance is a submatrix.

Throws:

java.lang.UnsupportedOperationException - if this object is not created by subMatrix(...) or subMatr(...) call.

See Also:

isSubMatrix()

subMatrixFrom

long[] subMatrixFrom()

If this matrix is a submatrix of some parent matrix, created by one of calls parent.subMatrix(...) or parent.subMatr(...), creates and returns a new Java array containing the starting position of this submatrix in the parent one. The result will be equal to "from" argument of subMatrix(long[], long[]) and subMatrix(long[], long[], Object) methods. If this matrix is not a submatrix, throws UnsupportedOperationException.

Returns:

low endpoints (inclusive) of all coordinates of this submatrix in its parent matrix.

Throws:

java.lang.UnsupportedOperationException - if this object is not created by subMatrix(...) or subMatr(...) call.

See Also:

isSubMatrix()

subMatrixTo

long[] subMatrixTo()

If this matrix is a submatrix of some parent matrix, created by one of calls parent.subMatrix(...) or parent.subMatr(...), creates and returns a new Java array containing the ending position (exlusive) of this submatrix in the parent one. The result will be equal to "to" argument of subMatrix(long[], long[]) and subMatrix(long[], long[], Object) methods. If this matrix is not a submatrix, throws UnsupportedOperationException.

Returns:

low endpoints (inclusive) of all coordinates of this submatrix in its parent matrix.

Throws:

java.lang.UnsupportedOperationException - if this object is not created by subMatrix(...) or subMatr(...) call.

See Also:

isSubMatrix()

isSubMatrix

boolean isSubMatrix()

Returns true if and only if this matrix is a submatrix of some parent matrix, created by one of calls parent.subMatrix(...) or parent.subMatr(...). The subMatrixParent() method throws UnsupportedOperationException if and only if this method returns false.

Returns:

whether this object is not created by subMatrix(...) or subMatr(...) call.

See Also:

subMatrix(long[], long[]), subMatrix(long[], long[], Object), subMatr(long[], long[]), subMatr(long[], long[], Object), subMatrixParent()

structureLike

Matrix<T> structureLike(Matrix<?> m)

Returns a view ot this matrix, where the elements are reordered in some order "like" in the specified matrix m. In other words, the elements of the built-in array of the returned matrix are the same as the elements of the built-in array of this one (any changes of the elements of the returned matrix are reflected in this matrix, and vice-versa), but the order of the elements can differ. The precise algorithm of reordering is not specified and depends of the matrix m: this method tries to help algorithms, processing the same or similar areas in both matrices, to provide maximal performance.

This method returns non-trivial results only if the matrix m is already a view of some other matrix with some form of reordering elements, for example, if m is a tiled matrix. In other case, this method just returns this instance.

In the current version of this package (if this instance was created by means of methods of this package), this method is equivalent to the following:

 m.isTiled() ?
     thisInstance.tile(m.tileDimensions()) :
     thisInstance;
 

In future versions, it is possible that this method will recognize other forms of reordering matrix elements and return non-trivial results for such m matrices.

Because the precise order of elements of the returning matrix is not specified, we recommend to use this method generally for newly created matrices, for example:

 memoryModel.newMatrix(UpdatablePArray.class, m).structureLike(m);
 

or, more briefly,

 memoryModel.newStructuredMatrix(UpdatablePArray.class, m);
 

Parameters:

m - some matrix, probably a view of another matrix with reordered elements (for example, tiled).

Returns:

a view of this matrix with elements reordered in similar order, or a reference to this instance if m matrix is not reodered or this method does not "know" about the way of that reordering.

Throws:

java.lang.NullPointerException - if m argument is null.

See Also:

isStructuredLike(Matrix)

isStructuredLike

boolean isStructuredLike(Matrix<?> m)

Returns true if the elements of this matrix is ordered "alike" the elements of the specified matrix m, in terms of structureLike(Matrix) method. "Orderer alike" does not mean that the dimensions of both matrices are equal, or that the detailes of the structure are the same; it means only that both matrices use similar reordering algorithms.

More precisely, structureLike(Matrix) method returns this instance if and only if this method returns true.

In the current version of this package (if this instance was created by means of methods of this package), this method is equivalent to: thisInstance.isTiled()==m.isTiled().

Parameters:

m - some matrix, probably a view of another matrix with reordered elements (for example, tiled).

Returns:

whether this matrix is reordered alike m.

Throws:

java.lang.NullPointerException - if m argument is null.

tile

Matrix<T> tile(long... tileDim)

Returns a view ot this matrix, where the elements are reordered by tiles: a grid of rectangular regions (tiles), the sizes of which are specified by tileDim argument. It means that the elements of the built-in AlgART array of the returned matrix are the elements of the built-in array of this one, but "shuffled" so that all elements of every tile in the returned matrix are located in a continuous block of the built-in array of this matrix. The returned matrix is named tiled matrix. The dimensions of the returned matrix are the same as the dimensions of this one. The element type of the returned matrix is identical to the element type of this matrix.

More precisely, let this matrix be M and the tiled matrix, returned by this method, be T. Let i₀, i₁, ..., i_n−1 (n=dimCount()) be coordinates of some element it the tiled matrix T, that is located in T.array() at the index i=T.index(i₀,i₁,...,i_n−1). This element is located in the original array M.array() at another index j, which is calculated by the following algorithm.

1. Let d_k = M.dim(k), k=0,1,...,n−1: dimensions of this and returned matrix.
2. Let i'_k = i_k%tileDim[k], k=0,1,...,n−1: i'_k are the coordinates of this element inside the tile, containing it in T matrix.
3. Let s_k = i_k−i'_k, k=0,1,...,n−1: s_k are the coordinates of the starting element of the tile, containing this element in T matrix.
4. Let t_k = min(tileDim[k], d_k−s_k), k=0,1,...,n−1: t_k are the dimensions of the tile, containing this element in T matrix. (Note that boundary tiles can be less than tileDim, if dimensions of matrix are not divisible by corresponding dimensions of tiles.)
5. Let previousVolume = d₀d₁...d_n−3d_n−2s_n−1 + d₀d₁...d_n−3c_n−2t_n−1 + ... + s₀t₁...t_n−2t_n−1. This complex formula returns the summary sizes of all tiles, that are fully located in the source T.array() before the given element. In 2-dimensional case, the formula is more simple: previousVolume = d_xs_y + s_xt_y.
6. Let indexInTile = i'₀ + i'₁t₀ + ... + i'_n−1t_n−2...t₀: it is the index of the element with coordinates i'₀,i'₁,...,i'_n−1 in the built-in array of a little matrix, dimensions of which are equal to the tile dimensions.
7. The required index of the given element in the original array M.array() is j = previousVolume + indexInTile.

Tiled matrices are necessary to provide good performance of many algorithms, if this matrix is very large (much greater than amount of RAM) and is located on disk or other external devices. For example, extracting a rectangular area 1000x1000 from a byte matrix 1000000x1000000 (1 terabyte) will probably work much faster if it is tiled, than if it is a usual matrix, where every line occupies 1 MB of continuous disk space.

In the degenerated case of 1-dimensional matrix (dimCount()=1) the tiled matrix is absolutely useless, though still works correctly.

Recommended tile dimensions are from several hundreds to several thousands, but it depends on the number of dimensions. If tile dimensions are degrees of two (2^k), the tiled matrix will probably work faster.

The built-in AlgART array of the returned matrix is backed by the built-in array of this matrix, so — if this matrix is not immutable — any changes of the elements of the returned matrix are reflected in this matrix, and vice-versa. The returned matrix is immutable if, and only if, the built-in array of this matrix does not implement UpdatableArray. The Array.asTrustedImmutable() method in the built-in array of the returned matrix is equivalent to Array.asImmutable(), and Array.asCopyOnNextWrite() method just returns the full copy of the array.

In the built-in array of the returned matrix, the following methods: newCompatibleEmptyArray(), newCompatibleEmptyArray(Class elementType), newCompatibleArray(long initialLength), newCompatibleArray(Class elementType, long initialLength), newCompatibleUnresizableArray(long length), newCompatibleUnresizableArray(Class elementType, long length) are based on the calls of the corresponding newCompatible... method of the built-in array of this matrix. It is the reason why this method does not use MemoryModel argument, unlike, for example, Arrays.asShifted(MemoryModel, Array, long).

Parameters:

tileDim - dimensions of the tiles in the returned matrix (excepting the boundary tiles, which can be less).

Returns:

a tiled view of this matrix.

Throws:

java.lang.NullPointerException - if tileDim argument is null.

java.lang.IllegalArgumentException - if tileDim.lengthdimCount(), or if some tileDim[k]<=0, or if the product of all tile dimensions tileDim[k] is greater than Long.MAX_VALUE.

See Also:

tile(), isTiled(), tileDimensions()

tile

Matrix<T> tile()

Returns a tiled view ot this matrix with some default dimensions of the tiles. Equivalent to tile(tileDim), where all elements of tileDim are equal to the default integer value, retrieved from the system property "net.algart.arrays.matrixTile2D", "net.algart.arrays.matrixTile3D" "net.algart.arrays.matrixTile4D" "net.algart.arrays.matrixTile5D" or "net.algart.arrays.matrixTileND", if the number of dimensions of this matrix is correspondingly 2, 3, 4, 5 or greater. If there is no such property, or if it contains not a number, or if some exception occured while calling Long.getLong, this method uses the following tile dimensions: 4096x4096 in 2-dimensional case, 256x256x256 in 3-dimensional case, 64x64x64x64 in 4-dimensional case, 32x32x32x32x32 in 5-dimensional case, 16x16x... if the number of dimensions is greater than 5. If the corresponding property exists and contains a valid integer number, but it is too small, in particlar, zero or negative, then it is replaced with some minimal positive value. The values of all these system property is loaded and checked only once while initializing Arrays class. If the number of dimensions is 1 (degenerated case), this method always uses 65536 as the tile size. (Warning! These defaults can be changed in future versions!)

Returns:

a tiled view of this matrix with default tile dimensions.

Throws:

java.lang.IllegalArgumentException - if the product of all tile dimensions tileDim[k] is greater than Long.MAX_VALUE.

See Also:

tile(long...), isTiled(), tileDimensions()

tileParent

Matrix<T> tileParent()

Not ready yet!

Returns:

original non-tiled matrix.

tileDimensions

long[] tileDimensions()

Not ready yet!

Returns:

dimensions of the tile in this matrix, if it is tiled.

isTiled

boolean isTiled()

Not ready yet!

Returns:

true if and only if this matrix is tiled.

isImmutable

boolean isImmutable()

Equivalent to array().isImmutable().

There is a guarantee that this method works very quickly.

Returns:

true if this instance is immutable.

isCopyOnNextWrite

boolean isCopyOnNextWrite()

Equivalent to array().isCopyOnNextWrite().

There is a guarantee that this method works very quickly.

Returns:

true if this instance is copy-on-next-write.

isDirectAccessible

boolean isDirectAccessible()

Returns true if and only if the built-in AlgART array implements DirectAccessible interface and ((DirectAccessible)array()).hasJavaArray() method returns true.

There is a guarantee that this method works very quickly.

Returns:

whether this matrix can be viewed as a Java array or a part of Java array.

isFresh

boolean isFresh()

Returns true if this matrix instance is fresh, that is if it was created by MemoryModel.newMatrix(Class, Class, long...) method or by one of methods MemoryModel.newBitMatrix(long...), MemoryModel.newByteMatrix(long...), ..., and if the built-in AlgART array is also fresh.

If the matrix is fresh, you can be sure that both it and its built-in AlgART array are not views of another matrix / array, but are the original objects created by the memory model.

The matrices, created by matrix(Array) and Matrices.matrix(Array, long...) methods, are never fresh. The matrix, returned by cast(Class) method, is fresh if and only if the source matrix is fresh.

There is a guarantee that this method works very quickly.

Returns:

whether this matrix instance if fresh.

flushResources

void flushResources(ArrayContext context)

Equivalent to array().flushResources(context).

Parameters:

context - the context of execution; may be null, then it will be ignored.

freeResources

void freeResources(ArrayContext context)

Equivalent to array().freeResources(context).

Parameters:

context - the context of execution; may be null, then it will be ignored.

toString

java.lang.String toString()

Returns a brief string description of this object.

The result of this method may depend on implementation and usually contains a short description of the built-in AlgART array and all matrix dimensions.

Overrides:

toString in class java.lang.Object

Returns:

a brief string description of this object.

hashCode

int hashCode()

Returns the hashcode of this matrix. The result depends on all elements of the built-in array (as Array.hashCode() and all matrix dimensions.

Overrides:

hashCode in class java.lang.Object

Returns:

the hashcode of this matrix.

equals

boolean equals(java.lang.Object obj)

Indicates whether some other matrix is equal to this one. Returns true if and only if:

1. the specified object is a matrix (i.e. implements Matrix),
2. both matrices have the same dimension count (dimCount()) and the same corresponding dimensions;
3. the built-in AlgART arrays (array()) are equal (see Array.equals(Object)).

Overrides:

equals in class java.lang.Object

Parameters:

obj - the object to be compared for equality with this matrix.

Returns:

true if the specified object is a matrix equal to this one.