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 2007-2008

Since:

JDK 1.5

Version:

1.1

Author:

Daniel Alievsky

See Also:

Array, UpdatableArray, MutableArray

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.

arrayType

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

Returns array().getClass(), 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 class of the built-in AlgART array.

Throws:

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

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

immutableArrayType

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

Returns array().asImmutable().getClass(), if it is subtype of (or same type as) the passed arraySupertype, or throws ClassCastException in other case. This method is useful if you need to get the class of immutable arrays, corresponding to the type of the built-in AlgART array.

Parameters:

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

Returns:

the class of immutable version of the built-in AlgART array.

Throws:

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

java.lang.ClassCastException - if arraySupertype does not allow storing the immutable version of 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).

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.

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().

long uncheckedIndex(long... coordinates)

long cyclicIndex(long... coordinates)

boolean inside(long... coordinates)

boolean inside(long x,
               long y)

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), asCopyOnNextWrite(), shallowClone(), updatableClone(), mutableClone() 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[]), subMatr(long[], long[], Object), subMatr(long[], long[])

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 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.

See Also:

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

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.

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.

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.

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 or dimY<0.

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 or dimZ<0.

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.

freeResources

void freeResources()

Equivalent to array().freeResources().

flushResources

void flushResources()

Equivalent to array().flushResources().

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.

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.