Interface DoubleNdArray

All Superinterfaces:
NdArray<Double>, Shaped
All Known Implementing Classes:
DoubleDenseNdArray, DoubleSparseNdArray, DoubleSparseSlice
public interface DoubleNdArray extends NdArray<Double>
An NdArray of doubles.

  • Method Details

    • getDouble

      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

    • setDouble

      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

    • streamOfDoubles

      default DoubleStream streamOfDoubles()
      Retrieve all scalar values of this array as a stream of doubles.

      For rank() > 1 arrays, all vectors of the last dimension are collated so that the scalar values are returned in sequential order.

      Returns:
      scalar values as a stream

    • withShape

      DoubleNdArray withShape(Shape shape)
      Description copied from interface: NdArray
      Returns a new N-dimensional view of this array with the given shape.

      The provided shape must comply to the following characteristics:

      • new shape is known (i.e. has no unknown dimension)
      • new shape size is equal to the size of the current shape (i.e. same number of elements)
      For example, 
         NdArrays.ofInts(Shape.scalar()).withShape(Shape.of(1, 1));  // ok
   NdArrays.ofInts(Shape.of(2, 3).withShape(Shape.of(3, 2));   // ok
   NdArrays.ofInts(Shape.scalar()).withShape(Shape.of(1, 2));  // not ok, sizes are different (1 != 2)
   NdArrays.ofInts(Shape.of(2, 3)).withShape(Shape.unknown()); // not ok, new shape unknown

      Any changes applied to the returned view affect the data of this array as well, as there is no copy involved.

      Specified by:
      withShape in interface NdArray<Double>
      Parameters:
      shape - the new shape to apply
      Returns:
      a new array viewing the data according to the new shape, or this array if shapes are the same

    • slice

      DoubleNdArray slice(Index... indices)
      Description copied from interface: NdArray
      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
   });
      Specified by:
      slice in interface NdArray<Double>
      Parameters:
      indices - index selectors per dimensions, starting from dimension 0 of this array.
      Returns:
      the element resulting of the index selection

    • get

      DoubleNdArray get(long... coordinates)
      Description copied from interface: NdArray
      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))

      Specified by:
      get in interface NdArray<Double>
      Parameters:
      coordinates - coordinates of the element to access, none will return this array
      Returns:
      the element at this index

    • set

      DoubleNdArray set(NdArray<Double> src, long... coordinates)
      Description copied from interface: NdArray
      Assigns the value of the N-dimensional element found at the given coordinates.

      The number of coordinates provided can be anywhere between 0 and rank - 1. For example: 

       FloatNdArray matrix = NdArrays.ofFloats(shape(2, 2));  // matrix rank = 2
 matrix.set(vector(10.0f, 20.0f), 0);  // success
 matrix.set(scalar(10.0f), 1, 0); // success
      Specified by:
      set in interface NdArray<Double>
      Parameters:
      src - an array of the values to assign
      coordinates - coordinates of the element to assign
      Returns:
      this array

    • getObject

      default Double getObject(long... coordinates)
      Description copied from interface: NdArray
      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); .
      Specified by:
      getObject in interface NdArray<Double>
      Parameters:
      coordinates - coordinates of the scalar to resolve
      Returns:
      value of that scalar

    • setObject

      default DoubleNdArray setObject(Double value, long... coordinates)
      Description copied from interface: NdArray
      Assigns 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.setObject(10.0f, 0, 1);  // succeeds
 matrix.setObject(10.0f, 0);  // throws IllegalRankException

 FloatNdArray scalar = matrix.get(0, 1);  // scalar rank = 0
 scalar.setObject(10.0f);  // succeeds
      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.setFloat(10.0f, 0);
      Specified by:
      setObject in interface NdArray<Double>
      Parameters:
      value - the value to assign
      coordinates - coordinates of the scalar to assign
      Returns:
      this array

    • elements

      NdArraySequence<DoubleNdArray> elements(int dimensionIdx)
      Description copied from interface: NdArray
      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 Shaped.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 Iterable.forEach(Consumer) or NdArraySequence.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);
   });
      Specified by:
      elements in interface NdArray<Double>
      Parameters:
      dimensionIdx - index of the dimension
      Returns:
      an NdArray sequence

    • scalars

      NdArraySequence<DoubleNdArray> scalars()
      Description copied from interface: NdArray
      Returns a sequence of all scalars in this array.

      This is equivalent to call elements(shape().numDimensions() - 1)

      Specified by:
      scalars in interface NdArray<Double>
      Returns:
      an NdArray sequence

    • copyTo

      DoubleNdArray copyTo(NdArray<Double> dst)
      Description copied from interface: NdArray
      Copy the content of this array to the destination array.

      The Shaped.shape() of the destination array must be equal to the shape of this array, or an exception is thrown. After the copy, the content of both arrays can be altered independently, without affecting each other.

      Specified by:
      copyTo in interface NdArray<Double>
      Parameters:
      dst - array to receive a copy of the content of this array
      Returns:
      this array

    • copyTo

      DoubleNdArray copyTo(DataBuffer<Double> dst)
      Description copied from interface: NdArray
      Copy the content of this N-dimensional array into the destination buffer.

      The size of the buffer must be equal or greater to the Shaped.size() of this array, or an exception is thrown. After the copy, content of the buffer and of the array can be altered independently, without affecting each other.

      Note: in version 0.4.0 and earlier, this method was named read(DataBuffer<T>). It has been renamed to explicitly indicate the direction of the data flow to avoid confusion.

      Specified by:
      copyTo in interface NdArray<Double>
      Parameters:
      dst - the destination buffer
      Returns:
      this array
      See Also:

    • copyTo

      DoubleNdArray copyTo(DoubleDataBuffer dst)

    • copyFrom

      DoubleNdArray copyFrom(DataBuffer<Double> src)
      Description copied from interface: NdArray
      Copy the content of the source buffer into this N-dimensional array.

      The size of the buffer must be equal or greater to the Shaped.size() of this array, or an exception is thrown. After the copy, content of the buffer and of the array can be altered independently, without affecting each other.

      Note: in version 0.4.0 and earlier, this method was named write(DataBuffer<T>). It has been renamed to explicitly indicate the direction of the data flow to avoid confusion.

      Specified by:
      copyFrom in interface NdArray<Double>
      Parameters:
      src - the source buffer
      Returns:
      this array
      See Also:

    • copyFrom

      DoubleNdArray copyFrom(DoubleDataBuffer src)