[R-sig-Geo] incompatible projections/coordinate-systems?

[Hans Ekbrand]

Hi list,

I'm a newcomer to GIS and r-sig-geo. I have exported some shapefiles
from ArcGIS and succeeded in plotting them with R. But one shapefile has
a different coordinate system, I think, and it does not turn up in the
graph when added to the others. In ArcGIS, this layer had an "unknown"
coordinate system, but rendered at the right location in relation to the
other layers.

I have made a tar-archive with the shape-files and a script to import
them into R and generate a map. The problematic shape is "sdn".

http://sociologi.cjb.net/temp/create-map-data.tbz
http://sociologi.cjb.net/temp/create-map.r

Here is the summary output of a "good" shape, "yta", followed by summary
of the problematic shape "sdn".

> summary(yta)

Object of class SpatialPolygonsDataFrame

Coordinates:

       min       max

r1  303850  344600.1

r2 6388900 6415400.0

Is projected: TRUE 

proj4string :

[+proj=utm +zone=33 +ellps=GRS80 +units=m +no_defs]

Data attributes:

      KKOD         SHAPE_AREA          SHAPE_LEN       

 Min.   :1.000   Min.   :7.812e+05   Min.   :    3530  

 1st Qu.:3.000   1st Qu.:1.125e+06   1st Qu.:    5514  

 Median :5.000   Median :3.006e+06   Median :    9121  

 Mean   :4.941   Mean   :1.272e+09   Mean   :  647692  

 3rd Qu.:7.000   3rd Qu.:1.685e+07   3rd Qu.:   37437  

 Max.   :7.000   Max.   :3.119e+10   Max.   :21081735  



> summary(sdn)

Object of class SpatialPolygonsDataFrame

Coordinates:

       min     max

r1 1247825 1288137

r2 6382086 6422038

Is projected: TRUE 

proj4string :

[+proj=tmerc +lat_0=0 +lon_0=15.80827777777778 +k=1 +x_0=1500000 +y_0=0

+ellps=bessel +units=m +no_defs]

Data attributes:

   SW_MEMBER           NAMN       DISTRIKT       REG_DATUM         DATUM   

 Min.   : 1   10 Högsbo  : 1   Centrum: 4   1996/01/01:21   2001/09/10:21  

 1st Qu.: 6   11 Älvsborg: 1   Norr   :10                                  

 Median :11   12 Frölunda: 1   Väster : 7                                  

 Mean   :11   13 Askim   : 1                                               

 3rd Qu.:16   14 Tynnered: 1                                               

 Max.   :21   15 Styrsö  : 1                                               

              (Other)    :15                                               

 OPERATör    KVALITET      AREA             PERIMETER    

 eoh:21   Min.   :0   Min.   :  3729696   Min.   :10507  

          1st Qu.:0   1st Qu.:  9113274   1st Qu.:15376  

          Median :0   Median : 16307500   Median :21493  

          Mean   :0   Mean   : 34423248   Mean   :26351  

          3rd Qu.:0   3rd Qu.: 34864909   3rd Qu.:32932  

          Max.   :0   Max.   :198632325   Max.   :64221