I posted this question on StackOverflow a while back but received no answer.
I have 9,150 polygons in my data set. I was trying to run a spatial autoregressive model (SAR) in spdep to test spatial dependence of my outcome variable. After running the model, I wanted to examine the direct/indirect impacts, but encountered an error that seems to have something to do with the length of neighbors in the weights matrix not being equal to n. I tried running the very same equation as SLX model (Spatial Lag X), and impacts() worked fine, even though there were some polygons in my set that had no neighbors. > # Defining queen contiguity neighbors for polyset and storing the matrix as > list > q.nbrs <- poly2nb(polyset) > listweights <- nb2listw(q.nbrs, zero.policy = TRUE) > # Defining the model > model.equation <- TIME ~ A + B + C > # Run SAR model > reg <- lagsarlm(model.equation, data = polyset, listw = listweights, > zero.policy = TRUE) > # Run impacts() to show direct/indirect impacts > impacts(reg, listw = listweights, zero.policy = TRUE) > Error in intImpacts(rho = rho, beta = beta, P = P, n = n, mu = mu, Sigma = > Sigma, : length(listweights$neighbours) == n is not TRUE What am I doing wrong? I am running Windows 10 machine with R 3.5.3 with the most up-to-date spdep package, if it helps. Thank you very much. Regards, Denys Dukhovnov _______________________________________________ R-sig-Geo mailing list R-sig-Geo@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-geo
