[R-sig-Geo] readOGR loses projection name?

[Roger Bivand]

On Mon, 11 Sep 2006, Tim Keitt wrote:

> My best guess is that you need to add your projection to one of the
> files in /usr/share/gdal or in the projection definition files shipped
> with rgdal. Please send it upstream if you do.

Yes. rgdal does take over the GDAL and PROJ data directories when the 
package is loaded, this was needed for a number of reasons but is a bit 
heavy handed. We can try to work out where to keep updates to the public 
GDAL/PROJ.4 tables.

Roger

> 
> THK
> 
> On 9/11/06, Zev Ross <zev at zevross.com> wrote:
> > Hi All,
> >
> > I think this is probably a simple one. I'm reading a shapefile, making a
> > couple of changes and then sending it back out to shapefile. I am making
> > no changes to the prj information but for some reason it seems that the
> > projection name is being lost in the process. This is a non-traditional
> > projection, one used by many California government agencies. It appears
> > that the actual projection information is being maintained correctly,
> > but I'd like to keep the name.
> >
> > Zev
> >
> > Here's the relevant piece of the code:
> >
> > myprj<-readOGR("c:/junk/monitors", layer="monitors_all")
> > showWKT(proj4string(myprj),file="c/junk/monitors_all.prj")
> >
> > here is the prj that I'm reading in
> >
> > PROJCS["NAD_1983_California_Teale_Albers",GEOGCS["GCS_North_American_1983",
> > DATUM["D_North_American_1983",SPHEROID["GRS_1980",6378137.0,298.257222101]],
> > PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Albers"],
> > PARAMETER["False_Easting",0.0],PARAMETER["False_Northing",-4000000.0],
> > PARAMETER["Central_Meridian",-120.0],PARAMETER["Standard_Parallel_1",34.0],
> > PARAMETER["Standard_Parallel_2",40.5],PARAMETER["Latitude_Of_Origin",0.0],UNIT["Meter",1.0]]
> >
> >
> > here is the output prj
> >
> > PROJCS["Unknown",GEOGCS["GCS_North_American_1983",
> > DATUM["D_North_American_1983",SPHEROID["GRS_1980",6378137,298.257222101]],
> > PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]],PROJECTION["Albers"],
> > PARAMETER["standard_parallel_1",34],PARAMETER["standard_parallel_2",40.5],
> > PARAMETER["latitude_of_origin",0],PARAMETER["central_meridian",-120],
> > PARAMETER["false_easting",0],PARAMETER["false_northing",-4000000],UNIT["Meter",1]]
> >
> >
> >
> > --
> > Zev Ross
> > ZevRoss Spatial Analysis
> > 303 Fairmount Ave.
> > Ithaca, NY 14850
> > (607) 277-0004 (phone)
> > (866) 877-3690 (fax toll-free)
> > zev at zevross.com
> > www.zevross.com
> >
> > _______________________________________________
> > R-sig-Geo mailing list
> > R-sig-Geo at stat.math.ethz.ch
> > https://stat.ethz.ch/mailman/listinfo/r-sig-geo
> >
> 
> 
> 

-- 
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