scipy.spatial.distance.dice

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

Compute the Dice dissimilarity between two boolean 1-D arrays.

The Dice dissimilarity between u and v, is

\[\frac{c_{TF} + c_{FT}} {2c_{TT} + c_{FT} + c_{TF}}\]

where \(c_{ij}\) is the number of occurrences of \(\mathtt{u[k]} = i\) and \(\mathtt{v[k]} = j\) for \(k < n\).

Parameters:

u : (N,) ndarray, bool

Input 1-D array.

v : (N,) ndarray, bool

Input 1-D 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:

dice : double

The Dice dissimilarity between 1-D arrays u and v.

Examples

>>> from scipy.spatial import distance
>>> distance.dice([1, 0, 0], [0, 1, 0])
1.0
>>> distance.dice([1, 0, 0], [1, 1, 0])
0.3333333333333333
>>> distance.dice([1, 0, 0], [2, 0, 0])
-0.3333333333333333