[GRASSLIST:6896] Re: v.proj problem

Francesco Mirabella mirabell at unipg.it
Thu May 26 12:00:41 EDT 2005


I found out that I had a problem only in one vector points map, not in
the others.
The problem was the in the originally imported ascii (v.in.ascii) as
some points did not have points (e.g.  longitude was 125674 rather than
12.5674)

When I imported the ascii (v.in.ascii) I did not get any error
(shouldn't I ???) and all the points were imported. 

The problem came out only when I re-projected to another location but
the error message was missleading (I think) as it was about: 

##################################
> >Input Projection Parameters: +proj=latlong +a=6378137
> >+rf=298.257223563
> >+no_defs +towgs84=0.000,0.000,0.000
> >Input Unit Factor: 1
> >
> >Output Projection Parameters: +proj=utm +zone=33 +a=6378388 +rf=297
> >+no_defs +towgs84=-87.000000,-98.000000,-121.000000
> >Output Unit Factor: 1
> >
> >Creating vector file...
> >pj_transform() failed
> >cause: geocentric transformation missing z or ellps
> >Error in pj_do_transform
> >GRASS 6.0.0 (umbmar):~ >
#################################

Hope this helps....

cheers
Francesco


On Thu, May 26, 2005 at 03:46:21PM +0100, Paul Kelly wrote:
> As far as I can remember, v.proj in 6.x has a "feature" that it interprets 
> the z co-ordinate of 3-D vectors as ellipsoidal height and tries to 
> convert it as part of the re-projection. In most cases this 
> interpretation will probably not  be correct. There really should be a 
> command-line flag to say 'interpret z co-ordinate as ellipsoidal height 
> and transform accordingly'.
> 
> Normally you would expect the z co-ordinate to remain unchanged, the way 
> I'm looking at it. I could be missing something though.
> 
> Not sure if this is related to you problem but thought I should mention 
> it.
> 
> Paul
> 
> 
> On Thu, 26 May 2005, Francesco Mirabella wrote:
> 
> >Hi to all,
> >I have reprojected 3d vector points from wgs84 lat long location to
> >utm33:
> >
> >-in the UTM 33 location:
> >v.proj input=data_wgs84  output=data_utm33 location=WGS_84_latlong 
> >mapset=PERMANENT
> >
> >I got the following error:
> >##################################
> >Input Projection Parameters: +proj=latlong +a=6378137 +rf=298.257223563
> >+no_defs +towgs84=0.000,0.000,0.000
> >Input Unit Factor: 1
> >
> >Output Projection Parameters: +proj=utm +zone=33 +a=6378388 +rf=297
> >+no_defs +towgs84=-87.000000,-98.000000,-121.000000
> >Output Unit Factor: 1
> >
> >Creating vector file...
> >pj_transform() failed
> >cause: geocentric transformation missing z or ellps
> >Error in pj_do_transform
> >GRASS 6.0.0 (umbmar):~ >
> >##################################
> >
> >can someone help?
> >Francesco
> >
> >p.s.
> >I did v.proj transformations some other times from the same location
> >into the utm33 location, but it is the first time that this error
> >occurred.
> >
> >




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