Known Indirect Subclasses |
An NdArray
of bytes.
Public Methods
abstract ByteNdArray | |
abstract NdArraySequence<ByteNdArray> |
elements(int dimensionIdx)
Returns a sequence of all elements at a given dimension.
|
abstract ByteNdArray |
get(long... coordinates)
Returns the N-dimensional element of this array at the given coordinates.
|
abstract byte |
getByte(long... coordinates)
Returns the byte value of the scalar found at the given coordinates.
|
abstract Byte |
getObject(long... coordinates)
Returns the value of the scalar found at the given coordinates.
|
abstract ByteNdArray |
read(DataBuffer<Byte> dst)
|
abstract ByteNdArray |
read(ByteDataBuffer dst)
|
abstract NdArraySequence<ByteNdArray> |
scalars()
Returns a sequence of all scalars in this array.
|
abstract ByteNdArray | |
abstract ByteNdArray |
setByte(byte value, long... coordinates)
Assigns the byte value of the scalar found at the given coordinates.
|
abstract ByteNdArray |
setObject(Byte value, long... coordinates)
|
abstract ByteNdArray | |
abstract ByteNdArray |
write(ByteDataBuffer src)
|
abstract ByteNdArray |
write(DataBuffer<Byte> src)
|
Inherited Methods
Public Methods
public abstract NdArraySequence<ByteNdArray> elements (int dimensionIdx)
Returns a sequence of all elements at a given dimension.
Logically, the N-dimensional array can be flatten in a single vector, where the scalars of
the (n - 1)
th element precedes those of the (n)
th element, for a total of
size()
values.
For example, given a n x m
matrix on the [x, y]
axes, elements are iterated in
the following order:
x0y0, x0y1, ..., x0ym-1, x1y0, x1y1, ..., xn-1ym-1
The returned sequence can then be iterated to visit each elements, either by calling
forEach(Consumer)
or forEachIndexed(BiConsumer)
.
// Iterate matrix for initializing each of its vectors
matrixOfFloats.elements(0).forEach(v -> {
v.set(vector(1.0f, 2.0f, 3.0f));
);
// Iterate a vector for reading each of its scalar
vectorOfFloats.scalars().forEachIdx((coords, s) -> {
System.out.println("Value " + s.getFloat() + " found at " + coords);
});
}
Parameters
dimensionIdx | index of the dimension |
---|
Returns
- an
NdArray
sequence
public abstract ByteNdArray get (long... coordinates)
Returns the N-dimensional element of this array at the given coordinates.
Elements of any of the dimensions of this array can be retrieved. For example, if the number of coordinates is equal to the number of dimensions of this array, then a rank-0 (scalar) array is returned, which value can then be obtained by calling `array.getObject()`.
Any changes applied to the returned elements affect the data of this array as well, as there is no copy involved.
Note that invoking this method is an equivalent and more efficient way to slice this array
on single scalar, i.e. array.get(x, y, z)
is equal to
array.slice(at(x), at(y), at(z))
Parameters
coordinates | coordinates of the element to access, none will return this array |
---|
Returns
- the element at this index
public abstract byte getByte (long... coordinates)
Returns the byte value of the scalar found at the given coordinates.
To access the scalar element, the number of coordinates provided must be equal to the number of dimensions of this array (i.e. its rank). For example:
ByteNdArray matrix = NdArrays.ofBytes(shape(2, 2)); // matrix rank = 2
matrix.getByte(0, 1); // succeeds, returns 0
matrix.getByte(0); // throws IllegalRankException
ByteNdArray scalar = matrix.get(0, 1); // scalar rank = 0
scalar.getByte(); // succeeds, returns 0
Parameters
coordinates | coordinates of the scalar to resolve |
---|
Returns
- value of that scalar
Throws
IndexOutOfBoundsException | if some coordinates are outside the limits of their respective dimension |
---|---|
IllegalRankException | if number of coordinates is not sufficient to access a scalar element |
public abstract Byte getObject (long... coordinates)
Returns the value of the scalar found at the given coordinates.
To access the scalar element, the number of coordinates provided must be equal to the number of dimensions of this array (i.e. its rank). For example:
FloatNdArray matrix = NdArrays.ofFloats(shape(2, 2)); // matrix rank = 2
matrix.getObject(0, 1); // succeeds, returns 0.0f
matrix.getObject(0); // throws IllegalRankException
FloatNdArray scalar = matrix.get(0, 1); // scalar rank = 0
scalar.getObject(); // succeeds, returns 0.0f
Note: if this array stores values of a primitive type, prefer the usage of the specialized
method in the subclass for that type. For example, floatArray.getFloat(0);
.Parameters
coordinates | coordinates of the scalar to resolve |
---|
Returns
- value of that scalar
public abstract NdArraySequence<ByteNdArray> scalars ()
Returns a sequence of all scalars in this array.
This is equivalent to call elements(shape().numDimensions() - 1)
Returns
- an
NdArray
sequence
public abstract ByteNdArray setByte (byte value, long... coordinates)
Assigns the byte value of the scalar found at the given coordinates.
To access the scalar element, the number of coordinates provided must be equal to the number of dimensions of this array (i.e. its rank). For example:
ByteNdArray matrix = NdArrays.ofBytes(shape(2, 2)); // matrix rank = 2
matrix.setByte(10, 0, 1); // succeeds
matrix.setByte(10, 0); // throws IllegalRankException
ByteNdArray scalar = matrix.get(0, 1); // scalar rank = 0
scalar.setByte(10); // succeeds
Parameters
value | the value to assign |
---|---|
coordinates | coordinates of the scalar to assign |
Returns
- this array
Throws
IndexOutOfBoundsException | if some coordinates are outside the limits of their respective dimension |
---|---|
IllegalRankException | if number of coordinates is not sufficient to access a scalar element |
public abstract ByteNdArray slice (Index... indices)
Creates a multi-dimensional view (or slice) of this array by mapping one or more dimensions to the given index selectors.
Slices allow to traverse an N-dimensional array in any of its axis and/or to filter only
elements of interest. For example, for a given matrix on the [x, y]
axes, it is
possible to iterate elements at y=0
for all x
.
Any changes applied to the returned slice affect the data of this array as well, as there is no copy involved.
Example of usage:
FloatNdArray matrix3d = NdArrays.ofFloats(shape(3, 2, 4)); // with [x, y, z] axes
// Iterates elements on the x axis by preserving only the 3rd value on the z axis,
// (i.e. [x, y, 2])
matrix3d.slice(all(), all(), at(2)).elements(0).forEach(m -> {
assertEquals(shape(2), m); // y=2, z=0 (scalar)
);
// Creates a slice that contains only the last element of the y axis and elements with an
// odd `z` coordinate.
FloatNdArray slice = matrix3d.slice(all(), at(1), odd());
assertEquals(shape(3, 2), slice.shape()); // x=3, y=0 (scalar), z=2 (odd coordinates)
// Iterates backward the elements on the x axis
matrix3d.slice(flip()).elements(0).forEach(m -> {
assertEquals(shape(2, 4), m); // y=2, z=4
});
}
Parameters
indices | index selectors per dimensions, starting from dimension 0 of this array. |
---|
Returns
- the element resulting of the index selection