Class Vectors

Create a sparse vector, using either a dictionary, a list of
(index, value) pairs, or two separate arrays of indices and
values (sorted by index).

@param size: Size of the vector.
@param args: Non-zero entries, as a dictionary, list of tupes,
             or two sorted lists containing indices and values.

>>> print Vectors.sparse(4, {1: 1.0, 3: 5.5})
(4,[1,3],[1.0,5.5])
>>> print Vectors.sparse(4, [(1, 1.0), (3, 5.5)])
(4,[1,3],[1.0,5.5])
>>> print Vectors.sparse(4, [1, 3], [1.0, 5.5])
(4,[1,3],[1.0,5.5])

Create a dense vector of 64-bit floats from a Python list. Always returns a NumPy array.

>>> Vectors.dense([1, 2, 3])
array([ 1.,  2.,  3.])

Converts a vector into a string, which can be recognized by Vectors.parse().

>>> Vectors.stringify(Vectors.sparse(2, [1], [1.0]))
'(2,[1],[1.0])'
>>> Vectors.stringify(Vectors.dense([0.0, 1.0]))
'[0.0,1.0]'