Folks:
Is there any way to take a GRASS raster and generate two outputs where
each pixel is the center coordinate of that pixel (e.g. you will have
one x- image and one y-image)? I'm trying to produce a latitude map
for solar calculations.
--j
--
Jonathan A. Greenberg, PhD
Assistant Project
Folks:
I was wondering if there is a way to turn the atmosphere off in
r.sun, and model a top of atmosphere radiation?
--j
--
Jonathan A. Greenberg, PhD
Assistant Project Scientist
Center for Spatial Technologies and Remote Sensing (CSTARS)
Department of Land, Air and Water Resources
Grass'ers:
I've recently learned the wonders of SVN, and was hoping to drop this
r.gridengine code I've been working on (it parallizes r.* commands
using grid engine) someplace so I can use SVN, and also have the code
easily available if anyone wants to try it out. I can use
sourceforge, but I
Hamish and co:
Thanks -- already went through the long, arduous task of running
r.horizon -- I think the main benefit is that, unlike r.sun, you can
set a fixed search window size (hint hint, this would be a nice
feature to add to r.sun) -- my understanding is that for each pixel in
a DEM, r.sun
Is is possible to use r.horizon steps that are in a different mapset
with r.sun? How would I use the prefix command, something like:
myhorizonpref...@anothermapset
?
--j
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What is the quickest way to calculate, at a given g.region, the
min/max of a set of rasters (which may have different resolutions) for
each pixel? Is this something that mapcalc can do?
--j
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feature to add to g.copy.
--j
On Mon, May 24, 2010 at 8:40 PM, Nikos Alexandris
nikos.alexand...@felis.uni-freiburg.de wrote:
Jonathan Greenberg wrote:
Excellent -- symlinking is working properly -- now on to my next
question -- is there a way to do some level of batch g.copy using a
wildcard, e.g
19, 2010 at 8:30 PM, Glynn Clements
gl...@gclements.plus.com wrote:
Jonathan Greenberg wrote:
So assuming that we have duplicated the projection info from one
filesystem to the next (the case I'm dealing with is running out of
space on one filesystem, and we needed to continue work on another
, and then symlink it within the identical location on
the other filesystem, would this work to allow me to g.copy (or,
indeed, allow me to reference the files using @ from both
filesystems?)
--j
On Fri, May 14, 2010 at 11:05 AM, Glynn Clements
gl...@gclements.plus.com wrote:
Jonathan Greenberg wrote:
I
I have some rasters in a grass data directory on a different mounted
drive in unix that i want to copy into a different data directory +
mapset -- i can't seem to figure out how to do this with g.copy, which
AFAIK only copies from mapsets within a given data directory.
Thoughts?
--j
Grassers:
I recall some time ago there was a way to hack grass (is this a more
formal boot-time option now?) and have it ignore .gislock to run concurrent
processes in the same mapset. I'm curious if this is still possible, and,
if so, if it would be safe to do this with multiple r.mapcalc runs
Folks:
I'm getting close to finishing up a generic code that sends any given
raster command to gridengine for parallel processing (I'll post it as
soon as its ready for testing), but I had a couple of quick question
on GRASS standards:
1) For a given mapset, is there a directory within it that
GRASSers:
I'm curious if anyone has developed any scripts to divide a raster
process up *spatially* across multiple processors, given a) a tile size
and b) an overlap size. We are hoping to run r.sun at 10m across
California, and would like to break up the full process into smaller
GRASSers:
Is there any way to generate a raster in which the pixel values are
the directions (in radians or degrees) to the nearest vector object,
e.g. a point, line, or polygon (nearest being calculated as Euclidean
distance)?
--j
--
Jonathan A. Greenberg, PhD
Postdoctoral Scholar
GRASSers:
I was curious -- how is tiled processing realized in GRASS GIS? Is
there a fixed input tile size (in MB of RAM or # of lines)? Is there
some documentation buried on the GRASS site that describes the
algorithm? I'm trying to replicate an efficient tiled approach in R --
I was
luck
milton
brazil=toronto
2009/7/8 Jonathan Greenberg greenb...@ucdavis.edu
mailto:greenb...@ucdavis.edu
GRASSers:
I was curious -- how is tiled processing realized in GRASS GIS?
Is there a fixed input tile size (in MB of RAM or # of lines)?
Is there some documentation
Excellent! So, yes, it turns out I hit my quota on the disk server --
our sysadmin raised it, but the same error was occurring. g.region -d
worked spectacularly! Thanks!
--j
Moritz Lennert wrote:
On 25/03/09 06:51, Markus Neteler wrote:
On Wed, Mar 25, 2009 at 4:42 AM, Jonathan Greenberg
GRASS was working fine and dandy, and after some weird crash with a
display window (I forgot to jot down the error), I can no longer launch
the GUI for a certain mapset under GRASS 6.4.svn on Debian. Here's the
error I get:
After choosing the mapset, the splash comes up, then the Output
I was hoping to try out the latest r.terracost (v 1.1 at the time of
this email) on our Debian installation of GRASS 6.3, and I'm getting
hung up on (following a make):
/var/tmp/grass/grass-6.3.0RC4/include/Make/Multi.make:4:
/var/tmp/grass/grass-6.3.0RC4/include/Make/Platform.make: No such
Sorry for the cross-posting. I was wondering if anyone has a unix
(preferably) or windows program that can spider a directory, recursively
searching for raster and vector data, and create bounding box polygons
for each raster/vector it finds, with attributes indicating the
path-to-file.
-related.
Hmm. Check the archives for Jonathan Greenberg -- he is one of the
lead developers. It would be nice to get starspan into OSGEO so that
questions / code patches ect. can be handled in an efficient manner.
Starspan is an emmensly important GIS tool, but suffers from a lack of
developers
I'll be presenting some work I did with GRASS in the RS for
biogeosciences poster session on Thursday morning -- how about a
Wednesday post-AGU happy hour meet? I can recommend a good
bar/restaurant nearby (Thirsty Bear, on Howard between 3rd and 2nd, 2
blocks from AGU), although, in full
I was hoping for a crash course in performing a spatial join between a
polygon and a point layer in GRASS. I want to know, for each polygon in
vector A, how many points from vector B fall within it, and the average,
min, max and stdev of several numeric fields of those points from vector
B
GISers:
I'm hoping to get a list of programs/databases that can deal with the
storage and querying of arbitrarily large vector (polygon) coverages (
2gb)? My understanding is, for instance, PostGIS (and the various
front-end interfaces) can deal with these types of data, but file
formats
On Thu, Oct 23, 2008 at 11:28 AM, Jonathan Greenberg
[EMAIL PROTECTED] wrote:
Hi all:
I went to run r.terraflow within out GRASS GIS 6.4 installation on our
Debian box and found it does not appear to exist anymore -- is there any
trick to getting it installed/running with GRASS 6.4? We did
Hi all:
I went to run r.terraflow within out GRASS GIS 6.4 installation on
our Debian box and found it does not appear to exist anymore -- is there
any trick to getting it installed/running with GRASS 6.4? We did a
standard ./compile - make - make install.
--j
--
Jonathan A. Greenberg,
So as a heads up, we actually built some functionality into starspan to
deal with the huge amount of time it takes to process texture images for
data exploration. If you check out the minirasterstrip output, it
allows you to take your field data, and produce a small strip of raster
windows
Wout:
This is more of a general response, rather than a how to for
GRASS. At 1m, you are absolutely going to need to include some level of
spatial processing (texture being the brute force way of getting at
these sorts of things). At that resolution, trees become multi-pixel
objects,
I'm curious -- where does GRASS write its temporary files, and how would
I change this if I wanted to? Thanks!
--j
--
Jonathan A. Greenberg, PhD
Postdoctoral Scholar
Center for Spatial Technologies and Remote Sensing (CSTARS)
University of California, Davis
One Shields Avenue
The Barn, Room
I have a point file that I would like to have the points snapped to the
nearest line in a different vector file (preferably anywhere along the
length of the line, although the nearest line node would be ok) -- how
do I do this in GRASS?
--j
--
Jonathan A. Greenberg, PhD
Postdoctoral Scholar
Don't fret! The command line is still there! The gui is just a wrapper
for the command line (check out the bottom of the gui -- you'll see the
command line populated).
--j
Nikos Alexandris wrote:
On Thu, 2008-07-31 at 15:59 -0700, Jonathan Greenberg wrote:
We've updated/fixed/improved
Nikos:
Performing relative radiometric normalization is a *requirement* of
applying a single classification to multiple images (also for change
detection). Unfortunately, it is not an algorithm that is available (to
my knowledge), out-of-the-box, on ANY remote sensing platform (GRASS,
Nikos:
Have you checked out any of the new minirasterstrip features in
starspan yet? It takes vector data (any format that OGR supports),
extracts a window (user defined size) around the vector out of a set of
rasters (anything that GDAL supports), compiles it into a single image,
and
We've updated/fixed/improved starspan over the past few months, and even
began to create a grass interface for it:
http://starspan.casil.ucdavis.edu/doku/doku.php?id=grass
Unfortunately, our amazing programmer Carlos Rueda has left for greener
pastures (congrats to Carlos on his new job!), so
GRASS'ers:
Although I don't echo Tim's dissapointment with GRASS (I use it
routinely and wouldn't trade it for the world), I do agree that GRASS is
more programmer-friendly than casual-user friendly environment. GRASS
reminds me, in many ways, of Arc/Info (pre-ArcMap, the 'ol command line
Milton:
I just had this questioned answered about 2 days before you posted it
on the grass-windows forums :) All you have to do is call the commands
from your bash script (assuming you are using bash), e.g. if you have a
text file that says:
g.region -p
g.region -p
Saved as
I'd like to pipe the output of r.in.xyz -s -g to g.region -- how do I do
this via command line?
--j
--
Jonathan A. Greenberg, PhD
Postdoctoral Scholar
Center for Spatial Technologies and Remote Sensing (CSTARS)
University of California, Davis
One Shields Avenue
The Barn, Room 250N
Davis, CA
By the way, I tried to do:
r.in.xyz -s -g [other parameters] | g.region
...but it didn't seem to change any of the region settings when I do a
g.region -p
--j
Jonathan Greenberg wrote:
I'd like to pipe the output of r.in.xyz -s -g to g.region -- how do I do
this via command line?
--j
Grass users:
I was hoping to get a jump start on an analysis that requires that I
perform a set of processes by looping through a set of poly features.
My question is -- does anyone have an example of how to do this in GRASS
(via bash scripting):
for i = 1, number of features in coverage
We're interested in working within GRASS to do some spectral analyses,
but we need to be able to access a z-profile programatically, more or
less on a pixel-by-pixel basis (e.g. we don't think we can use r.mapcalc
to solve our problems). Here's a for instance, and let me know if this
is
From: Jonathan Greenberg [EMAIL PROTECTED]
Subject: Re: [GRASS-user] value differences between landsat images
To: Juan Manuel Barreneche [EMAIL PROTECTED]
Cc: grass-user@lists.osgeo.org
Message-ID: [EMAIL PROTECTED]
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Juan:
It just
Juan:
I think you are talking about radiometric normalization between images.
This is performed by first extracting values of pseudoinvariant
features (PIFs) in the overlap zones between images -- these are
features which should be the same, spectrally. If you have a set of
band values of
Actually, I think r.terraflow has that! look for the TCI output!
--j
Moskovitz, Bob wrote:
It would be cool to see something like the Topographic Position Index(TPI) in GRASS.
Details here: http://www.jennessent.com/downloads/TPI-poster-TNC_18x22.pdf
-Original Message-
From:
Quick question: I have a colleague who is using 6.2.3 CYGWIN version of
grass, and was wondering how people felt about that version (and
platform's) stability vs. 6.3.0 (windows or *nix) or 6.2.3 *nix
versions. I'm pretty convinced that 6.2.3 for cygwin is very moody and
unstable, but I don't
So if I understand this correctly, you have some polygon surface that
defines the extent of your subbasin, which you want to use to query and
summarize the raster values falling within it (e.g. precip and temp),
correct? How are you doing it currently? The main speedup that
starspan gets you
Hey guys, wanted to echo this -- we are continuing development on
starspan again -- it works with gdal 1.5, among other improvements, and
if you have any feature requests (or if anyone can help us make this
into a grass package :), please email me or Carlos Rueda!
--j
Nikos Alexandris wrote:
If I have a r.cost surface calculated from a set of vector points used
as starting points, and some cost surface, is there any way to easily
retrieve the SOURCE vector ID that leads to the lowest cost to get to
any cell in the raster? E.g. from a given point, where is the point
that costs the
Is there any way to access a bash window for the Windows mingw version
of grass 6.3? What do I need to do? Thanks!
--j
--
Jonathan A. Greenberg, PhD
Postdoctoral Scholar
Center for Spatial Technologies and Remote Sensing (CSTARS)
University of California, Davis
One Shields Avenue
The Barn,
I've switched to using the mingw version -- msys comes with a command
line sh.exe, but I can't seem to a) boot grass using it, and b) and
suspicious it won't be able to run bash scripting (sh is not the same as
bash, correct?)
--j
WolfgangZ wrote:
Jonathan Greenberg schrieb:
Is there any
(sorry for the barrage of emails, i'm finagling with nnbathy today and
having some problems with import/exporting into grass). Ok, so the awk
suggestions worked wonders to fix my xyz file. Now when I do an
r.in.xyz, its failing because nnbathy outputted a NaN z-value for a
couple of
Is there a quick way to clip a vector file to the current region bounds?
--j
--
Jonathan A. Greenberg, PhD
Postdoctoral Scholar
Center for Spatial Technologies and Remote Sensing (CSTARS)
University of California, Davis
One Shields Avenue
The Barn, Room 250N
Davis, CA 95616
Cell: 415-794-5043
There are ongoing issues with various windows incarnations of GRASS.
Cygwin has had some issues with large files and higher memory addressing
pretty much since its incarnation (I wrestled with this quite a bit a
few years back). You might want to try the new grass binary that relies
on
While I like the generality of the fitted r.param.scale algorithm
(indeed, it is used in other software packages as well) to classify
various morphometric features, I am trying to find a tool which uses
more classic, 3x3 moving window approaches to classify features, e.g. a
peak looks like:
Seems like http://debian.gfoss.it/preview/ has been down for a few days
-- is there a mirror for the debian binary of GRASS? Any word on when
the RC4 binary will be released?
--j
--
Jonathan A. Greenberg, PhD
Postdoctoral Scholar
Center for Spatial Technologies and Remote Sensing (CSTARS)
Total vector noob question: if I have several point files that I want to
merge into a single file, how do I do this? Does the topology have to
be built in able to perform this action?
--j
--
Jonathan A. Greenberg, PhD
Postdoctoral Scholar
Center for Spatial Technologies and Remote Sensing
Quick question: is there a functional difference between the shadow
algorithm found in r.sun and r.sunmask? I'd like to use a ray-trace
based shadowing algorithm -- if r.sunmask does this (the documentation
doesn't indicate whether or not it does), it seems that would be a
faster alternative
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