[GRASS-dev] Re: [GRASS GIS] #785: wx location wizard: doesn't show all datum transform opts

GRASS GIS trac at osgeo.org
Sun Oct 11 00:48:48 EDT 2009

#785: wx location wizard: doesn't show all datum transform opts
  Reporter:  hamish    |       Owner:  grass-dev at lists.osgeo.org
      Type:  defect    |      Status:  new                      
  Priority:  critical  |   Milestone:  6.4.0                    
 Component:  wxGUI     |     Version:  svn-develbranch6         
Resolution:            |    Keywords:  location wizard          
  Platform:  Linux     |         Cpu:  x86-64                   
Comment (by hamish):

 g.proj --help says:
   datumtrans   Index number of datum transform parameters
                 "0" for unspecified or "-1" to list and exit

 so in this case valid options to pass g.proj for that are 0-6.

  g.proj datumtrans=-1  proj4="+proj=lcc +datum=nad83"

 North American Datum 1983 (nad83) is chronologically very close to 1984,
 so +towgs84=0,0,0 isn't too surprising (same for any datum post-satellite
 era), the others (2-6) are all NTv2 grid file transforms (is NAD83 a
 continental plate-bound datum?).

 I see the g.proj -t and -d flags, but not really sure if they help.

 here are the valid options I was describing for my neck of the woods:
  g.proj proj4="+proj=nzmg +datum=nzgd49" datumtrans=-1

 If I guess correctly you are looking at parsing the g.proj datumtr=-1
 output instead of the datumtransform.table file?


Ticket URL: <https://trac.osgeo.org/grass/ticket/785#comment:6>
GRASS GIS <http://grass.osgeo.org>

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