geolime.utilities.distance

Data:

Callable

Callable type; Callable[[int], str] is a function of (int) -> str.

Functions:

anisotropic_distance([a])	Anisotropic distance between two points according to the anisotropy matrix a.
distance_matrix(x1, x2[, distance])	Computes the distance matrix of two sets of points in the Euclidean space according to a distance.
euclidian_distance(x, y)	Compute the Euclidean distance between two points.
pairwise(coords)	Computes pairwise distances
pdist(X[, metric])	Pairwise distances between observations in n-dimensional space.
squareform(X[, force, checks])	Convert a vector-form distance vector to a square-form distance matrix, and vice-versa.

geolime.utilities.distance.anisotropic_distance(a: numpy.ndarray = array([[1.0, 0.0, 0.0], [0.0, 1.0, 0.0], [0.0, 0.0, 1.0]]))

Anisotropic distance between two points according to the anisotropy matrix a. This function DOES NOT compute a distance matrix. See distance_matrix function.

Parameters

a (np.ndarray) – A must be an invertible square (numpy) matrix.

Returns

This function returns a function f(X,Y) which computes de anistropic distance between X and Y.

Return type

Callable

geolime.utilities.distance.distance_matrix(x1: numpy.ndarray, x2: numpy.ndarray, distance: Callable = <function euclidian_distance>)

Computes the distance matrix of two sets of points in the Euclidean space according to a distance.

Parameters

• x1 (np.ndarray) – A numpy matrix with the vectors to be analized in its rows.

• x2 (np.ndarray) – A numpy matrix with the vectors to be analized in its rows (it must have the same number of columns as X1)

• distance (Callable) – A distance function

Returns

This functions returns a numpy matrix, where the (i,j)-th element corresponds to the distance between the i-th row of X1 and the j-th row of X2.

Return type

np.ndarray

geolime.utilities.distance.euclidian_distance(x: numpy.ndarray, y: numpy.ndarray)

Compute the Euclidean distance between two points. x and y must be: - Two numpy arrays of same dimension - One numpy matrix and one numpy array, obtaining a numpy vector of distances between the rows of the matrix and the numpy vector (there must be a column compatibility) - Two numpy matrices of the same shape, obtaining a numpy vector with the distances between their rows.

Parameters

• x (np.ndarray) – First array for distance computation

• y (np.ndarray) – Second array for distance computation

Returns

Distance vector

Return type

np.ndarray

geolime.utilities.distance.pairwise(coords: numpy.ndarray)

Computes pairwise distances

Parameters

coords (np.ndarray) – array of cartesian coordinates (float)

Returns

an N * N matrix with pairwise distances

Return type

np.ndarray