[GRASS-user] Projection Units and Values Negatively Affect r.topidx Results

[Hamish]

Rich wrote:
> > 2) use v.in.region
> 
> v.in.region out=coverage type=area
> 
> > 2) get resolution in meters with g.region -m (applies
> only to raster map reprojection)
> 
> GRASS 6.4.0svn (oregonM):/usr4/grassbase > g.region -m
> n=1735231.43724681
> s=1120657.1324816
> w=143667.18968253
> e=952979.22944945
> nsres=32.82281055
> ewres=32.82281055
> rows=18724
> cols=24657
> cells=461677668
> 
>   The resolution is still in feet (or is this now seen
> as 32.8 meters?
> 
>   This is where I'm hung up.


try switching to grass 6.5 for a minute, and running r.proj -p
and or -g. The output of -g can be pasted directly into g.region,
and then it is an easy 'g.region -p', 'g.region res= -ap' to
clean it up. It is a real breath of fresh air after all the
quiting & restarting grass + v.in.region tricks, although that
is still a nice check to do.


check that the PROJ_UNITS in your source location is valid.

do not expect coords to be the same, they start off counting
from 0,0 somewhere far off to the south west and cover a
different number of units to get to Oregon based on their length.



Hamish