[R-sig-Geo] e00 to SpatialPolygons: how to set the correct projection

Hans-Jörg Bibiko bibiko at eva.mpg.de
Mon Jan 26 11:49:14 CET 2009


I was able to convert an e00 file to a SpatialPolygons object (thanks  
a lot to everybody who was involved to set up this functionality!) by  
using 'e00toavc' and 'pal2SpatialPolygons'.

But now I'm a bit lost in conversion. How to set the correct  
projection which is needed for 'pal2SpatialPolygons'?

My prj.adf file says:

Projection    LAMBERT
Zunits        NO
Units         METERS
Spheroid      CLARKE1866
Xshift        0.0000000000
Yshift        0.0000000000
  25  0  0.000 /* 1st standard parallel
  47  0  0.000 /* 2nd standard parallel
  110  0  0.000 /* central meridian
  10  0  0.000 /* latitude of projection's origin
0.00000 /* false easting (meters)
0.00000 /* false northing (meters)

and I want to use the data together with Roger Bivand's "http://spatial.nhh.no/R/etc/TM_WORLD_BORDERS_SIMPL-0.2.RData 
" data whose proj4string is set to

"+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs +towgs84=0,0,0"

I tried:
NMG <- pal2SpatialPolygons(arcs,pal, IDs=IDs, proj4string =  
CRS("+proj=longlat +ellps=clrk66"))

but it ended in:

Error in validityMethod(object) :
Geographical CRS given to non-conformant data

If I skip the proj4string in 'pal2SpatialPolygons' I get
NMG at bbox
         min     max
r1 -1037807 1141001
r2  3093775 4892464

By looking at this bbox and the actual area given in the e00 file I  
image that the bbox should be:
         min     max
r1  103.7807 114.1001
r2  30.93775 48.92464

Many thanks for any hint in advance!



Hans-Joerg Bibiko
Max Planck Institute for Evolutionary Anthropology
Department of Linguistics
Deutscher Platz 6     phone:   +49 (0) 341 3550 341
D-04103 Leipzig       fax:     +49 (0) 341 3550 333
Germany               e-mail:  bibiko at eva.mpg.de

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