libpysal.weights.
vecW
(origin_x, origin_y, dest_x, dest_y, threshold, p=2, alpha=-1.0, binary=True, ids=None, build_sp=False, **kwargs)[source]¶Distance-based spatial weight for vectors that is computed using a 4-dimensional distance between the origin x,y-coordinates and the destination x,y-coordinates
of vector origin x-coordinates
of vector origin y-coordinates
of vector destination x-coordinates
of vector destination y-coordinates
distance band
Minkowski p-norm distance metric parameter: 1<=p<=infinity 2: Euclidean distance 1: Manhattan distance
If true w_{ij}=1 if d_{i,j}<=threshold, otherwise w_{i,j}=0 If false wij=dij^{alpha}
distance decay parameter for weight (default -1.0) if alpha is positive the weights will not decline with distance. If binary is True, alpha is ignored
values to use for keys of the neighbors and weights dicts
True to build sparse distance matrix and false to build dense distance matrix; significant speed gains may be obtained dending on the sparsity of the of distance_matrix and threshold that is applied
optional arguments for pysal.weights.W
vectors origin and destination coordinates.
Examples
>>> import libpysal
>>> x1 = [5,6,3]
>>> y1 = [1,8,5]
>>> x2 = [2,4,9]
>>> y2 = [3,6,1]
>>> W1 = libpysal.weights.vecW(x1, y1, x2, y2, threshold=999)
>>> list(W1.neighbors[0])
[1, 2]
>>> W2 = libpysal.weights.vecW(x1, y2, x1, y2, threshold=8.5)
>>> list(W2.neighbors[0])
[1, 2]