Hi all,

I am trying to run an autologistic model using the function errorsarlm from spdep package. 

**I built an XY matrix extracting the two colums from matriz**

coords1<-matriz[matriz$casos1==1, c(4,5)]
coords1<-as.matrix(coords1)

**I identify neighbours of region points**

nb20<-dnearneigh(coords1,0,20,longlat=TRUE)

** I build a neighbours list with spatial weights**

nb20.w<-nb2listw(nb20, glist=NULL, style="W", zero.policy=TRUE)

**I run a glm**

glm1<-glm(matriz$sp~poly(matriz$iso,3)+poly(matriz$tmax,3)+poly(matriz$mdr,3)+poly(matriz$twq,3)+poly(matriz$tmin,3)+poly(matriz$pdq,3)+poly(matriz$trng,3),data=matriz, subset=matriz$casos1>0, family=binomial)
glm.scope<-list("var1"=~1+iso+poly(iso,2)+poly(iso,3),"var2"=~1+tmax+poly(tmax,2)+poly(tmax,3),"var3"=~1+mdr+poly(mdr,2)+poly(mdr,3),"var4"=~1+twq+poly(twq,2)+poly(twq,3),"var5"=~1+tmin+poly(tmin,2)+poly(tmin,3),"var6"=~1+pdq+poly(pdq,2)+poly(pdq,3),"var7"=~1+trng+poly(trng,2)+poly(trng,3),"var8"=~1+mdr+poly(mdr,2)+poly(mdr,3))
final.glm1<-step.gam(glm1,glm.scope,direction="back")

**I want to estimate the spatial simultaneous autoregressive error model**

res20<-errorsarlm(finalglm1, listw=nb20.w, zero.policy=TRUE)

But here I receive the following error message:

Error in solve.default(asyvar, tol = tol.solve) : 
  system is computationally singular: reciprocal condition number = 2.8713e-12

What is happening? What does this message mean? 

Thanks a lot,

Alberto

---------------------------------------
Alberto Jiménez-Valverde
Natural History Museum and Biodiversity Research Center
The University of Kansas
Lawrence, Kansas 66045 USA
email 1: ajvalv@ku.edu
email 2: alberto.jimenez.valverde@gmail.com
CV: http://www.biogeografia.com/CV/ajimenez/albertojimenezvalverde.htm

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