| Known Indirect Subclasses |
An NdArray of doubles.
Public Methods
| abstract DoubleNdArray | |
| abstract NdArraySequence<DoubleNdArray> |
elements(int dimensionIdx)
Returns a sequence of all elements at a given dimension.
|
| abstract DoubleNdArray |
get(long... coordinates)
Returns the N-dimensional element of this array at the given coordinates.
|
| abstract double |
getDouble(long... coordinates)
Returns the double value of the scalar found at the given coordinates.
|
| abstract Double |
getObject(long... coordinates)
Returns the value of the scalar found at the given coordinates.
|
| abstract DoubleNdArray |
read(DataBuffer<Double> dst)
|
| abstract DoubleNdArray |
read(DoubleDataBuffer dst)
|
| abstract NdArraySequence<DoubleNdArray> |
scalars()
Returns a sequence of all scalars in this array.
|
| abstract DoubleNdArray | |
| abstract DoubleNdArray |
setDouble(double value, long... coordinates)
Assigns the double value of the scalar found at the given coordinates.
|
| abstract DoubleNdArray |
setObject(Double value, long... coordinates)
|
| abstract DoubleNdArray | |
| abstract DoubleNdArray |
write(DataBuffer<Double> src)
|
| abstract DoubleNdArray |
write(DoubleDataBuffer src)
|
Inherited Methods
Public Methods
public abstract NdArraySequence<DoubleNdArray> 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
NdArraysequence
public abstract DoubleNdArray 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 double getDouble (long... coordinates)
Returns the double 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:
DoubleNdArray matrix = NdArrays.ofDoubles(shape(2, 2)); // matrix rank = 2
matrix.getDouble(0, 1); // succeeds, returns 0.0
matrix.getDouble(0); // throws IllegalRankException
DoubleNdArray scalar = matrix.get(0, 1); // scalar rank = 0
scalar.getDouble(); // succeeds, returns 0.0
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 Double 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
floatArray.getFloat(0); .Parameters
| coordinates | coordinates of the scalar to resolve |
|---|
Returns
- value of that scalar
public abstract NdArraySequence<DoubleNdArray> scalars ()
Returns a sequence of all scalars in this array.
This is equivalent to call elements(shape().numDimensions() - 1)
Returns
- an
NdArraysequence
public abstract DoubleNdArray setDouble (double value, long... coordinates)
Assigns the double 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:
DoubleNdArray matrix = NdArrays.ofDoubles(shape(2, 2)); // matrix rank = 2
matrix.setDouble(10.0, 0, 1); // succeeds
matrix.setDouble(10.0, 0); // throws IllegalRankException
DoubleNdArray scalar = matrix.get(0, 1); // scalar rank = 0
scalar.setDouble(10.0); // succeeds
Parameters
| value | 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 DoubleNdArray 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