[R-sig-Geo] projectRaster() to Goode Homolosine

[Birgit Mannig]

Thanks for the fast answer!

This is the extent as given by the USGS -- it's a global map.  
Actually, what is given is:

Projection Type: Interrupted Goode Homolosine
     Units of measure: meters
     Pixel Size: 1000 meters
     Radius of sphere: 6370997 m.
     XY corner coordinates (center of pixel) in projection units (meters):
         Lower left: (-20015000, -8673000)
         Upper left: (-20015000, 8673000)
         Upper right: (20015000, 8673000)
         Lower right: (20015000, -8673000)


The "interrupted areas" (where there is no real map/world) are filled  
with dummy values in the binary file.
Note the difference in sign for xmn/xmx and ymn/ymx. The resulting  
plot looks fine.

All the best,
Birgit


Zitat von Forrest Stevens <forrest at ufl.edu>:

> Hi Birgit, there's something wrong with your call to raster() as the
> xmin/xmax and ymin/ymax values should not be identical.  Could you
> confirm what the proper extent should be for the raster you're
> creating?
>
> Forrest
>
> On Tue, Jun 4, 2013 at 12:27 PM, Birgit Mannig
> <birgit.mannig at uni-wuerzburg.de> wrote:
>> Dear all,
>>
>> I tried to project a Raster file (orignal projection: UTM) to a file in the
>> Goode projection.
>> The re-projection with proj4 was obviosly not correct, neither was a
>> re-projection from a geographical lon/lat file.
>> Does anyone know if this is a general problem with R/proj4?
>>
>> Otherwise, I might have produced a faulty raster file. I used the USGS
>> Global Ecosystem Data (http://edc2.usgs.gov/glcc/globdoc2_0.php), provided
>> as raw binary, and had to create the Raster myself:
>>
>> ny <- 17347
>> nx <- 40031
>> goge <-
>> raster(xmn=-20015500,xmx=20015500,ymn=-8673500,ymx=8673500,nrows=ny,ncols=nx,crs="+proj=goode
>> +a=6370997")
>> values(goge) <- binfromFTP
>>
>> Although the created Raster File looked good to me naturally the error could
>> still occur in this step.
>>
>> Afterwards I just used:
>> projectRaster(infile,goge, method="ngb")
>>
>>
>> Any hints are very much appreciated!
>>
>> Kind regards,
>> Birgit
>>
>> _______________________________________________
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>> R-sig-Geo at r-project.org
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>
>
>
> --
> Forrest R. Stevens
> Ph.D. Candidate, QSE3 IGERT Fellow
> Department of Geography
> Land Use and Environmental Change Institute
> University of Florida
> www.clas.ufl.edu/users/forrest
>



-- 
Dipl.-Geogr. Birgit Mannig

Universität Würzburg
Institut für Geographie und Geologie
-Physische Geographie-
Zi. 120
Am Hubland
97074 Würzburg

Tel. +49-931-31-81319
Fax. +49-931-31-85544
birgit.mannig at uni-wuerzburg.de