shish matt <shishm <at> yahoo.com> writes: > > Hi: > First my apologies for cross-posting. A few days back I posted my queries ar R-sig-geo but did not get any > response. Hence this post.
Since your message never reached that list - did you check? - that isn't very surprising. Try again properly on R-sig-geo. > > I am working on two parcel-level housing dataset to estimate the impact of various variables on home sale > prices. > > I created the spatial weight metrics in ArcGIS 10 using sale > year of four nearest houses to assign weights. Create them in R, much less error prone. knn2nb(knearneigh()). A lot of problems arise from badly imported weights, but yours below seem OK. > Next, I ran LM tests and > then ran the spatial lag and error models using spdep package. > > I run into five issues. > > Issue 1: When I weight the 10,000-observation first dataset, I get the following message: Non-symmetric > neighbors list. > > Is this going to pose problems while running the regression models? If yes, what can I do? What do you think? If you are using nearest neighbours, only a very unusual set of points would give symmetric neighbours, and that would likely also have subgraph problems. > > Issue 2: The spatial lag and error models do not run. I get > the following message (the models runs on half the data, approx. 5,000 > observations. However, I will like to use the entire sample). > Read the help pages, method= argument. For larger data sets, use "LU" or perhaps "MC" when the weights are not symmetric. > Error: cannot allocate vector of size 880.0 Mb .solve=1.0e-20) > > When I am able to read the data file using filehash package. > However, I still get the following error message when I run the models: > Error in matrix(0, nrow = n, ncol = n) : too many elements specified No idea, almost certainly caused by not reading the documentation. Try on the original list. > [[alternative HTML version deleted]] > > DO follow the rule of not posting HTML! ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
