[GRASS-user] ogr2ogr and r to vect

[Daniel Farnan]

Thank you very much, this is something I will pursue as this project gets
more on its feet. 
Currently my difficulty with ogr2ogr is where to put the file to be
re-projected, so the program knows where to find it. It looks from the
examples that it should be in root, and the program run at command line and
not through GRASS? My initial inclination was to set the .shp file in the
main location folder outside of the mapsets and run via the GRASS command
prompt, though as I look further in to the OGR documentation it seems there
are other ways to do so, but no directions on where to put the .shp (SSURGO)
file. 
I have started with a new location which should display the ortho photos
with d.rgb, but does not in GRASS, though it will in QGIS in the location,
using the GRASS tools to open the current region, in Debian - odd, I am
still looking at the data for a clue, the projection is consistent as is the
location.
As to smoothing the 'steps,'
I recently came across references to improving the analysis of raster data
by expanding the analysis capabilities to work with the cell data, by
re-thinking the centroid (I think an 'R' related article I was looking at) -
I could not find the exact reference again, but maybe the 'TURKU' project
libral raster algebra library could be of help in smoothing steps -
http://sourceforge.net/project/showfiles.php?group_id=123937&package_id=1358
33&release_id=399025 

Thank you for the r to vect assistances, I look forward to working  that up.
:-) Daniel 

-----Original Message-----
From: grassuser-bounces at grass.itc.it
[mailto:grassuser-bounces at grass.itc.it]On Behalf Of Dylan Beaudette
Sent: Monday, January 08, 2007 1:25 PM
To: grassuser at grass.itc.it
Cc: carlos.grohmann at gmail.com
Subject: Re: [GRASS-user] ogr2ogr and ortho/rgb display


On Monday 08 January 2007 12:29, Maciej Sieczka wrote:
> Carlos "Guâno" Grohmann wrote:
> >> Please note that reprojecting a floating point grid will usually yield
> >> "stairs" distortion in the output, depending on how big is the skew
> >> between the input and output projection. That's propably what Dylan
> >> meant. The "stairs" distortion will be the bigger, the less smoothing
> >> involved in the reprojection.
> >
> > Maciek,
> >
> > are you aware of any publication that explain this kind of distortion?
>
> No.
>
> Maciek

" Necessity is the mother of invention " ... sounds like a fine time to
write 
this up!

I am actually in the process of doing this type of analysis for another 
project if anyone is interested in collaborating.

Cheers,

Dylan

-- 
Dylan Beaudette
Soils and Biogeochemistry Graduate Group
University of California at Davis
530.754.7341

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