Dear List, I'm trying to replicate results from several sources that analyze the Clayton and Kaldor (1987) Scottish Lip Cancer data using a Poisson GLMM with spatial correlation structure using a simple exponential variogram model. The only way (I think) that my data are different from the published data are that i'm using the Lat/Long instead of the OSGB projection.
Here is what I've tried: scot<-read.csv("scotland.csv") names(scot) scot$aff<-scot$AFF/10 scot$x<-scot$Longitude scot$y<-scot$Latitude scot$smr<-scot$Observed/scot$Expected scot$logsmr<-log(scot$smr+1) coordinates(scot)=~x+y library(MASS) library(nlme) #This is the first try, using the corEXP() directly in glmmPQL fit<-glmmPQL(Observed~offset(log(Expected))+aff,family=poisson, data=scot, random=~1|District, correlation=corExp(form=~x+y), niter=200) #it fails with: iteration 1 Error in corFactor.corSpatial(object) : NA/NaN/Inf in foreign function call (arg 1) In addition: Warning messages: 1: In min(unlist(attr(object, "covariate"))) : no non-missing arguments to min; returning Inf 2: In min(unlist(attr(object, "covariate"))) : no non-missing arguments to min; returning Inf #Then I try to initialize the spatial correlation as in ASDAR sp2<-corSpatial( form=~x+y, type="exponential") spcor<-Initialize(sp2, as(scot, "data.frame")[,c("x","y")]) glmmPQL(Observed~offset(log(Expected))+aff,family=poisson, data=scot, random=~1|District, correlation=spcor, niter=200, na.action="na.omit") #This fails with: iteration 1 iteration 2 iteration 3 iteration 4 iteration 5 Error in lme.formula(fixed = zz ~ offset(log(Expected)) + aff, random = ~1 | : nlminb problem, convergence error code = 1 message = function evaluation limit reached without convergence (9) Basically, i'm wondering if anyone can get this to work, because i'm at my wits end. My system info is: sessionInfo() R version 2.11.1 (2010-05-31) x86_64-apple-darwin9.8.0 locale: [1] en_US.UTF-8/en_US.UTF-8/C/C/en_US.UTF-8/en_US.UTF-8 attached base packages: [1] stats graphics grDevices utils datasets methods base other attached packages: [1] nlme_3.1-96 MASS_7.3-6 gstat_0.9-69 sp_0.9-64 loaded via a namespace (and not attached): [1] grid_2.11.1 lattice_0.18-8 tools_2.11.1 Best, Corey I'm pasting in the data, in case anyone wants to have a look: District,Observed,Expected,AFF,Latitude,Longitude 1,9,1.4,16,57.29,5.5 2,39,8.7,16,57.56,2.36 3,11,3,10,58.44,3.9 4,9,2.5,24,55.76,2.4 5,15,4.3,10,57.71,5.09 6,8,2.4,24,59.13,3.25 7,26,8.1,10,57.47,3.3 8,7,2.3,7,60.24,1.43 9,6,2,7,56.9,5.42 10,20,6.6,16,57.24,2.6 11,13,4.4,7,58.12,6.8 12,5,1.8,16,58.06,4.64 13,3,1.1,10,57.47,3.98 14,8,3.3,24,54.94,5 15,17,7.8,7,56.3,3.1 16,9,4.6,16,57,3 17,2,1.1,10,57.06,4.09 18,7,4.2,7,55.65,2.88 19,9,5.5,7,57.24,4.73 20,7,4.4,10,55.35,2.9 21,16,10.5,7,56.75,2.98 22,31,22.7,16,57.12,2.2 23,11,8.8,10,56.4,5.27 24,7,5.6,7,55.63,3.96 25,19,15.5,1,56.2,3.3 26,15,12.5,1,56.1,3.6 27,7,6,7,55.24,4.09 28,10,9,7,55.95,2.8 29,16,14.4,10,56.6,4.09 30,11,10.2,10,55.9,3.8 31,5,4.8,7,55.47,4.55 32,3,2.9,24,55,4.36 33,7,7,10,55.83,3.2 34,8,8.5,7,56.3,4.73 35,11,12.3,7,55.29,4.98 36,9,10.1,0,55.94,4.95 37,11,12.7,10,55.76,5.02 38,8,9.4,1,55.91,4.18 39,6,7.2,16,56.15,4.99 40,4,5.3,0,56.05,4.91 41,10,18.8,1,55.88,4.82 42,8,15.8,16,56.03,4 43,2,4.3,16,56.15,3.96 44,6,14.6,0,55.82,4.09 45,19,50.7,1,55.93,3.4 46,3,8.2,7,55.65,4.75 47,2,5.6,1,55.71,4.45 48,3,9.3,1,55.79,4.27 49,28,88.7,0,55.9,4.55 50,6,19.6,1,56.45,3.2 51,1,3.4,1,56,4.27 52,1,3.6,0,56.15,4.64 53,1,5.7,1,55.79,4.7 54,1,7,1,55.99,4.45 55,0,4.2,16,55.68,3.38 56,0,1.8,10,55.18,3.4 -- Corey Sparks Assistant Professor Department of Demography and Organization Studies University of Texas at San Antonio 501 West Durango Blvd Monterey Building 2.270C San Antonio, TX 78207 210-458-3166 corey.sparks 'at' utsa.edu https://rowdyspace.utsa.edu/users/ozd504/www/index.htm _______________________________________________ R-sig-Geo mailing list R-sig-Geo@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo