generate_W: Generate a random spatial weight matrix.
Description
Generate a spatial weight matrix of given size and number of nearest
neighbors from randomly-located observations on the unit square.
Usage
generate_W(n, nneigh, seed=123)
Arguments
n
the size of the matrix.
nneigh
the number of nearest neighbors.
seed
an integer to set the seed for the random generated
locations.
Value
a matrix of class dgCMatrix (sparse matrix).
Details
The output matrix has zero diagonal and it is row-standardised.
The n observations are allocated randomly in the unit square.
For each observation, the nneigh closests observations w.r.t. the
Euclidean distance are assigned with a weight equal to 1/nneigh.