pysal.lib.weights.WSP

class pysal.lib.weights.WSP(sparse, id_order=None)[source]

Thin W class for spreg.

Parameters:
sparse : sparse_matrix

NxN object from scipy.sparse

id_order : list

An ordered list of ids, assumed to match the ordering in sparse.

Examples

From GAL information

>>> import scipy.sparse
>>> from pysal.lib.weights import WSP
>>> rows = [0, 1, 1, 2, 2, 3]
>>> cols = [1, 0, 2, 1, 3, 3]
>>> weights =  [1, 0.75, 0.25, 0.9, 0.1, 1]
>>> sparse = scipy.sparse.csr_matrix((weights, (rows, cols)), shape=(4,4))
>>> w = WSP(sparse)
>>> w.s0
4.0
>>> w.trcWtW_WW
6.395
>>> w.n
4
Attributes:
n : int

description

s0 : float

s0 is defined as:

trcWtW_WW : float

Trace of \(W^{'}W + WW\).

Methods

from_W(W) Constructs a WSP object from the W’s sparse matrix
to_W([silence_warnings]) Convert a pysal WSP object (thin weights matrix) to a pysal W object.
__init__(sparse, id_order=None)[source]

Initialize self. See help(type(self)) for accurate signature.

Methods

__init__(sparse[, id_order]) Initialize self.
from_W(W) Constructs a WSP object from the W’s sparse matrix
to_W([silence_warnings]) Convert a pysal WSP object (thin weights matrix) to a pysal W object.

Attributes

diagWtW_WW Diagonal of \(W^{'}W + WW\).
s0 s0 is defined as:
trcWtW_WW Trace of \(W^{'}W + WW\).