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

[Roger Bivand]

On Mon, 26 Jan 2009, Hans-Jörg Bibiko wrote:

> Hi,
>
> 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
> Parameters
> 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"))

No. Your data are in a Lambert projection, probably lcc, but possibly 
laea, with the +lat_*= and +lon_0= arguments given. If 110 is 110E, you 
are somewhere in Asia, but knowing how muddled things get, it may be 110W, 
so -110, and North or Central America. If you have access to rgdal, try 
reading the Arc binary vector data directly, the driver may pick up the 
projection automatically.

Roger

>
> 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!
>
> Best,
>
> --Hans
>
> **********************************************************
> 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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-- 
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