[R-sig-Geo] Map2Poly: Error message

[Graham Cookson]

Dear List,

I hope you can help me with this problem.

I am attempting to form an adjacency matrix and I'm trying to get my
shapefile into R. However, I get error messages at the initial stages.

I used the following code:
library(maptools)
library(spdep)
map<-read.shape("englandandwales.shp")
polylist<-Map2poly(map)

The map object is created fine and it finds all 8490 polygons, but the
Map2poly command generates the following error message:

Error in if (res[[6]] > 0) return(as.integer(-1)) else return(as.integer(1))

I have searched the web and the R Help Archives but can't find examples of
this problem occurring before.

The shapefile I am using was  created in ArcView by merging the separate
Wales and England shapefiles available from UK Borders at Edina.ac.uk

I am using R2.2.0 on an Apple iBook G4 running Mac OS X 10.3.9

I hope that this isn't a really stupid question

Thanks!
Graham





-- 
Graham Cookson
Centre for Environmental Policy
Imperial College London
4th Floor, RSM Building
Prince Consort Road
London  SW7 2BP

Tel: 020 7594 9313
Mob: 07968 061323
Email: graham.cookson at imperial.ac.uk