Module « scipy.spatial.distance »

Fonction canberra - module scipy.spatial.distance

Signature de la fonction canberra

def canberra(u, v, w=None) 

Description

canberra.__doc__

    Compute the Canberra distance between two 1-D arrays.

    The Canberra distance is defined as

    .. math::

         d(u,v) = \sum_i \frac{|u_i-v_i|}
                              {|u_i|+|v_i|}.

    Parameters
    ----------
    u : (N,) array_like
        Input array.
    v : (N,) array_like
        Input array.
    w : (N,) array_like, optional
        The weights for each value in `u` and `v`. Default is None,
        which gives each value a weight of 1.0

    Returns
    -------
    canberra : double
        The Canberra distance between vectors `u` and `v`.

    Notes
    -----
    When `u[i]` and `v[i]` are 0 for given i, then the fraction 0/0 = 0 is
    used in the calculation.

    Examples
    --------
    >>> from scipy.spatial import distance
    >>> distance.canberra([1, 0, 0], [0, 1, 0])
    2.0
    >>> distance.canberra([1, 1, 0], [0, 1, 0])
    1.0