[GRASS-user] Output of g.proj?

Thomas Huld thomas.huld at jrc.ec.europa.eu
Tue Mar 29 05:26:20 EDT 2011


I am trying to use the r.out.gmap script from grass-addons. This script 
generates map tiles for Google Maps based on an existing raster. 

I have generated a new location/mapset using the special EPSG code of 900913, 
defined at the end of /usr/local/share/proj/esri.extra. 

But when I try r.out.gmap it gives me an error:

ERROR: projection for location "google2" differs from required google map
       mercator projection
current projection: +proj=merc +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0
+k=1.0 +no_defs +a=6378137 +rf=298.257223563
+nadgrids=/usr/local/grass-6.4.1RC2/etc/nad/@null +to_meter=1
required projection: +proj=merc +lat_ts=0.0000000000 +lon_0=0.0000000000
+k_0=1.0000000000 +x_0=0 +y_0=0 +no_defs +a=6378137 +b=6378137

(google2 being my new location).

(This happens both with GRASS-6.4.1RC2 and 6.4.0RC4)

The info on the current projection  in the script comes from the output of 
g.proj -jf.

This is slightly different from the information in esri.extra, which is 
identical to the "required projection" printed out in the error message.

Hence a couple of quick questions:

1) Does the difference mean I did something wrong in the definition of the 

2) Does it matter? If you use the -f ('force') option to r.out.gmap it seems 
to work.

3) If (not 1)&&(not 2), I would suggest changing the r.out.gmap script to 
reflect the current output from g.proj.



Thomas Huld   
Joint Research Centre of the European Commission
T.P. 450
I-21027 Ispra, Italy
phone: +39 0332785273
e-mail: Thomas.Huld at jrc.ec.europa.eu

More information about the grass-user mailing list