[GRASS-user] Landsat classification workflow
Hi list, I'm looking for a tutorial on classifying landsat images with GRASS. I can't seem to find anything on the web. Some pointers would be nice. Kind regards, Koen Hufkens ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] Re: shortest / less steep path in DEM
Forgot to post to the list as well, In short, combine both the length cost map and the steepness (r.slope output) cost map (according to your preference). Use this output as input for a final cost calculation. That should do the trick I think, Koen On Tue, 2009-02-17 at 14:15 +, Georg Kaspar wrote: On Tue, 17 Feb 2009 13:39:15 +, Georg Kaspar wrote: Hi, to calculate the shortest path from a mountain top into the valley, I ususally use r.flow [...] sorry, I meant r.drain... ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] menu items
Updated the FAQ... Should work for most systems as described in the FAQ Koen Op 11-feb-09, om 18:03 heeft Markus Neteler het volgende geschreven: On Wed, Feb 11, 2009 at 10:59 AM, Glynn Clements gl...@gclements.plus.com wrote: Koen Hufkens wrote: I'm cleaning up my grass scripts and making them user friendly using the g.parser module. However, I'm wondering if it is possible to add a menu item to the gis manager window in a similar fashion. I found d.menu but this doesn't do what I expected it to do. Any tips and hints on how to add on an extra menu item in the gis.m gis manager? You need to modify $GISBASE/etc/gm/gmmenu.tcl. Or alternatively, create $GISBASE/etc/xtnmenu.dat file, or dir/xtnmenu.dat for any dir in $GRASS_ADDON_ETC. However, I'm not entirely sure of the format; examine the code at the top of gmmenu.tcl for clues. ...added as new FAQ: http://grass.osgeo.org/wiki/GIS_manager Markus ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
[GRASS-user] menu items
Hi list, I'm cleaning up my grass scripts and making them user friendly using the g.parser module. However, I'm wondering if it is possible to add a menu item to the gis manager window in a similar fashion. I found d.menu but this doesn't do what I expected it to do. Any tips and hints on how to add on an extra menu item in the gis.m gis manager? Kind regards, Koen ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
[GRASS-user] r.le.patch no output
Hi list, I experience some really strange behaviour across all my platforms for r.le.patch. Whatever I throw at it I get no output... the output says tracing patch etc but no results are recorded. I experience similar behaviour with large filenames some time ago but all files I use have no extreme long input or output filenames. A simple command like: r.le.patch map=map sam=w siz=s1 out=tmp gives nothing on all my computers... My mac workstation that does the heavy work. My laptop I use for testing and writing code... All of them got infected with the r.le.patch not working bug. Has anyone experienced similar behaviour? I find it very strange that every single one experiences the same behaviour although they were fine just a few days back. I'm running 6.3.0-2 across all systems (mac and linux) Kind regards, Koen ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
[GRASS-user] Import / mapset problem
Hi list, I've got some issues with importing data into a mapset. I have been working on data that I imported into GRASS without any problems up until today. I noticed that although I import everything into a x, y lattice with no geospatial reference data some of my recent files get other parameters and do not align with my previous ones. All maps are tiff files with the same x, y size and should align perfectly however some have mapunits 2.4 (m? could be possible as this is roughly the spatial resolution of the image) others have mapunits 1. Futhermore, the older data seems to have been in some kind of projection as the cursor values display not the expected x y range corresponding to the number of pixels in the image. I suspect that this difference is the cause of my problems. However, I do use r.in.gdal with the overwrite protection settings so normally everything should have been imported without spatial reference data that could be embedded in the (geo)tiff header, or am I mistaken. Any ideas why my first files still have some spatial reference data embedded even after explicitly saying not to use them at import? Any solutions to get rid of unwanted geotiff headers? Kind regards, Koen ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
[GRASS-user] windowing / cropping very large raster layer
Hi list, I should crop a small area out of a large raster layer (3GB) to make it more manageable. I don't seem to find a quick way to do this. Is there a function that just takes, xy or column row input to extract a small subset and write it to a new (independent) layer? Kind regards, Koen ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
[GRASS-user] complex reclass / r.reclass segmentation fault
Hi list, I have a problem with r.reclass. I received a file with 2300 different integer class values in a raster format. However every one of these 2300 different integer values is actually a combination of main and subclasses. As I am only interested in the main classes I used a lookup table to determine how I had to group the classes according to my interest. I made r.reclass rules file like: 1 2 3 6 9 ... 450 123 456 ... = 1 3 4 10 ... 325 698 ... = 2 11 12 23 54 ... 654 789 222 = 3 end The file was created using the exported sorted values from an exell sheet, removing the endlines and replacing them with spaces to convert from a column to a row in text format using tr -s '\n' ' ' class1 temp1 and copy pasting the temp1 files with the '= foo' statement at the end to the final rules file. However, this results in a segmentation fault if I run the rule with r.reclass.file. Running r.reclass.file on the same raster dataset with an arbitrary rule 1 thru 1000 = 1 1000 thru 2000 = 2 end does not result in a segmentation fault. Now I know I use alot of values (2300 of them in the reclass rule) but could this be the cause of the segmentation fault. Anything I have to look out for when creating such long rules (new lines, carriage returns etc etc). Any clues? Kind regards, Koen ___ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
Re: [GRASS-user] complex reclass / r.reclass segmentation fault
Indeed if I split up the rules file in with less than 100 categories at
the lhs it works.
Thanks,
Koen
On Tue, 2008-02-26 at 12:33 +, Glynn Clements wrote:
Koen Hufkens wrote:
I have a problem with r.reclass.
I received a file with 2300 different integer class values in a raster
format. However every one of these 2300 different integer values is
actually a combination of main and subclasses. As I am only interested
in the main classes I used a lookup table to determine how I had to
group the classes according to my interest.
I made r.reclass rules file like:
1 2 3 6 9 ... 450 123 456 ... = 1
3 4 10 ... 325 698 ... = 2
11 12 23 54 ... 654 789 222 = 3
end
However, this results in a segmentation fault if I run the rule with
r.reclass.file.
Now I know I use alot of values (2300 of them in the reclass rule) but
could this be the cause of the segmentation fault. Anything I have to
look out for when creating such long rules (new lines, carriage returns
etc etc). Any clues?
r.reclass appears to have a limit of 100 categories on the LHS of a
rule. Any more than that and it will probably just crash.
You can have multiple rules with the same RHS, so you can just split
each rule into multiple rules, each with less than 100 categories.
It's probably easiest to just make one rule for each category, e.g.:
while read line ; do
lhs=${line%%=*}
rhs=${line##*=}
for cat in $lhs ; do
echo $cat = $rhs
done
done old-rules.txt new-rules.txt
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