[R-sig-Geo] CRS for the European Biogeographical Regions in R

[Roland Kaiser]

Hi!

Sorry for the confusion, I followed the link on the top the page "Note: new version is available!“.
For some reason, this ZIP archive has a *.qpj instead of *.prj file.

Of course, readOGR treats the *prj correctly, if present!

-Roli

> Am 08.02.2015 um 12:37 schrieb Barry Rowlingson <b.rowlingson at lancaster.ac.uk>:
> 
> On Sat, Feb 7, 2015 at 4:53 PM, Roland Kaiser <kardinal.eros at gmail.com> wrote:
> 
>> #       the projection information is given in the *.qpj file
> 
> I can't see a *.qpj file in that shapefile. There is a *.prj file
> which contains projection info.
> 
>> #       unfortunately, it is not read from the dataset by the OGR driver
> 
> The *.prj file **is** read when using readOGR:
> 
>> r=readOGR(".","BiogeoRegions2011")
> OGR data source with driver: ESRI Shapefile
> Source: ".", layer: "BiogeoRegions2011"
> with 12 features and 4 fields
> Feature type: wkbPolygon with 2 dimensions
>> proj4string(r)
> [1] "+proj=laea +lat_0=52 +lon_0=10 +x_0=4321000 +y_0=3210000
> +ellps=GRS80 +units=m +no_defs"
> 
> - that's a full projection specification, rather than an epsg code
> though, because that's what's in the file.
> 
>> #       we have do define it manually by specifing argument p4s
> 
> No we don't!
> 
>> pg <- readOGR(dsn = "BiogeoRegions2011_shapefile",
>>        layer = "BiogeoRegions2011", p4s = "+init=epsg:3035")
> 
> Is the .prj file text coding the same projection as epsg:3035?
> http://epsg.io/ says 3035 is:
> 
> +proj=laea +lat_0=52 +lon_0=10 +x_0=4321000 +y_0=3210000 +ellps=GRS80
> +towgs84=0,0,0,0,0,0,0 +units=m +no_defs
> 
> So yes. But there's no need to specify it in readOGR since you have
> the .prj file. The maptools functions readShapeSpatial and friends
> ignore the .prj file - I don't know why they exist any more!
> 
>> r2=readShapeSpatial("BiogeoRegions2011.shp")
>> proj4string(r2)
> [1] NA
> 
> Ouch.
> 
> Barry