impacts in spdep does not work for me when there is only one predictor
On Tue, 28 Sep 2010, Roger Bivand wrote:
On Tue, 28 Sep 2010, Eelke Folmer wrote:
Dear Roger and others, Using the impacts function in spdep to calculate distributions (on the regression parameters from the spatial lag model) I encountered the following problem: when there is only one exogenous predictor in the model the impacts function won't give the output summary of the mcmc simulations. Given the time the function takes to produce the error I think that the simulations do run.
Thanks for a clear report and reproducible example. I'll confirm when a fix has been committed to R-forge - it is caused ny matrix dimensions being dropped when there is only one row or column in some settings.
Fixes committed to the spdep project on R-Forge, could those interested please check before I release to CRAN? The packages on R-Forge should be revision 339, release 0.5-23, so for example Windows binaries for R patched will be available after midnight CET. Roger
Best wishes, Roger
I tried the same on the columbus data where it also happens example(columbus) listw <- nb2listw(col.gal.nb) lobj <- lagsarlm(CRIME ~ INC, columbus, listw) summary(lobj) imp <- impacts(lobj, listw=birds.wlist, R=100) summary(imp, zstats=TRUE) Error in dimnames(x) <- dn : length of 'dimnames' [2] not equal to array extent lobj <- lagsarlm(CRIME ~ INC + HOVAL, columbus, listw) summary(lobj) imp <- impacts(lobj, listw=birds.wlist, R=100) summary(imp, zstats=TRUE) works fine. I hope I didn't miss anything obvious. Thanks in advance, Eelke
Roger Bivand Economic Geography Section, Department of Economics, Norwegian School of Economics and Business Administration, Helleveien 30, N-5045 Bergen, Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43 e-mail: Roger.Bivand at nhh.no