scipy.spatial.distance.canberra

scipy.spatial.distance.canberra(u, v, w=None)

Compute the Canberra distance between two 1-D arrays.

The Canberra distance is defined as

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

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