pairwise_distances#

pairwise_distances(x, y=None, *, exponent=1)[source]#

Pairwise distance between points.

Return the pairwise distance between points in two sets, or in the same set if only one set is passed.

Parameters

  • x (Array) – An \(n \times m\) array of \(n\) observations in a \(m\)-dimensional space.

  • y (Optional[Array]) – An \(l \times m\) array of \(l\) observations in a \(m\)-dimensional space. If None, the distances will be computed between the points in \(x\).

  • exponent (float) – Exponent of the Euclidean distance.

Returns

A \(n \times l\) matrix where the \((i, j)\)-th entry is the distance between \(x[i]\) and \(y[j]\).

Return type

Array

Examples

>>> import numpy as np
>>> import dcor
>>> a = np.array([[1, 2, 3, 4],
...               [5, 6, 7, 8],
...               [9, 10, 11, 12],
...               [13, 14, 15, 16]])
>>> b = np.array([[16, 15, 14, 13],
...               [12, 11, 10, 9],
...               [8, 7, 6, 5],
...               [4, 3, 2, 1]])
>>> dcor.distances.pairwise_distances(a)
array([[ 0.,  8., 16., 24.],
       [ 8.,  0.,  8., 16.],
       [16.,  8.,  0.,  8.],
       [24., 16.,  8.,  0.]])
>>> dcor.distances.pairwise_distances(a, b)
array([[24.41311123, 16.61324773,  9.16515139,  4.47213595],
       [16.61324773,  9.16515139,  4.47213595,  9.16515139],
       [ 9.16515139,  4.47213595,  9.16515139, 16.61324773],
       [ 4.47213595,  9.16515139, 16.61324773, 24.41311123]])