GRASS GIS (Geographic Resources Analysis Support System) is a free, open source geographical information system (GIS) capable of handling raster, topological vector, image processing, and graphic data.
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Raster image outside Grass screen, How to get it inside from start?
HI ALL: I'm new in Grass and need some help!
I have created a LOCATION based on the coordinate system in which I want my data to be projected. So far I'm being able to Import & display the raster ...
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40 views
After pansharpening LANDSAT 8 in GRASS, poor colour visualisation in QGIS afterwards
Having used QGIS for quiet some time for mapping, I was 'forced' to dig into GRASS as pansharpening is not directly executable in QGIS. After understanding more or less the structure, I did some ...
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1answer
38 views
Is it possible to import/run AML script into GRASS?
I have an AML script that has instructions to import tmp files of (grid, network, basin...)
is there any way to run the script in GRASS? I tried to converted to Python but I couldn't do it for the ...
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1answer
33 views
Use of Grass and R w.r.t. Land Use Prediction
In my data mining term project I need to conduct a work on geospatial data related to a big city to show possible urbanization fields in next years. I've used GRASS lately on other projects so I'm a ...
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9 views
How do I determine the area of a raster map in GRASS in real world units? [duplicate]
I know that in the metadata it gives you the number of cells, but how do you find out what area (in, for example, metres squared) a cell represents?
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16 views
GRASS 6.4.3RC3, Python script and windows7
I'm trying to solve my problem for a long time. I hope someone can help me. I'm not expert but I really want to istall 2 add-on on grass 6.4.3RC3 on my win7. The add-ons are r.basin and r.ipso. I ...
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21 views
Python errore addons (win)
I have this type of error when I try to use r.ipso:
C:\Program Files (x86)\GRASS GIS
6.4.3RC3\extrabin\python.exe: can't open file 'r.ipso.py':
[Errno 2] No such file or directory
while with r.basin ...
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36 views
r.basin.py GRASS addon
I have added this add on with g.extension on my grass 6.4.3RC3. But it doesnt work... this is the error I can see:
Traceback (most recent call last): File "C:\Program Files (x86)\GRASS GIS ...
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2answers
62 views
Grass 6 extension installation in Grass 7 error
I am trying to install the extension r.roughness from the Grass 6 repository, but in Grass 7.
When trying g.extensions, the error "make: * No rule to make target ...
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28 views
SEXTANTE v.to.rast.attribute issue in script
I'm trying to convert a vector layer to a raster by using the GRASS function v.to.rast.attribute in Python.
My code doesn't throw any error but the raster image is only a square of 1px. But when I'm ...
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37 views
Add-ons on GRASS (win7)
Can someone help me fro istalling add on on GRASS 6.4.3RC3 (windows7)?? I tryed several mode but I'm not able. I found several topic here and into the web but it doesn't works.
I use g.extension, I ...
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25 views
How can I calculate raster cell area for upslope contributing area
I am new to spatial analysis, and urgently trying to follow this tutorial to generate a topographic wetness index for my area of interest:
...
4
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1answer
75 views
R gridding and contouring options
I want to make an interactive web mapping application, which will grid and contour user data. My plan is to implement R scripts with Shiny, but the only R package I can find to do this is gstat. And ...
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15 views
How to access layer attributes using grass network tools (v.net.iso)?
I had a quick look for a similar question, sorry if this is a duplicate.
I am using GRASS 6.4.3 on windows - osgeo4w version
I ran v.net.iso to split my road network by cost however when I try to ...
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59 views
How to setup and use GRASS?
Previously I've asked an question and Micha gave me a helpful advice:How to find the watershed area for each point in the river network using DEM？
After getting the useful DEM file, I began to setup ...
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1answer
29 views
3D Interpolation using point cloud in GRASS GIS
I've imported a set of 3D points (z,y,z) into GRASS GIS. I'm having trouble: a) visualising my dataset in 3D using nviz or the standard data viewer (I can only get a 2D plan view of my data) and, b) ...
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31 views
how to loop grass command in python and put variable in output file
anyone,
first day Grass programming with python scripting;
first prob;
simple I want to reclass the same raster several times;
and save the file with the value loop variable at the end ...
can not ...
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1answer
22 views
How to estimate distance from points to line feature with v.distance?
I'm trying to use the v.distance module in GRASS 6.4.3 to estimate the distance from a series of point features (animal tracking locations) to the nearest point along a line feature (a coastline). I ...
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44 views
How to create a topologically correct dataset in PostGIS (with GRASS)?
I have shapefiles which I have loaded in postgis and now i am trying to use geometric function in postgis like ST_intersect and they fail because the data is not topological correct.
I have tried to ...
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1answer
87 views
How to find the watershed area for each point in the river network using DEM？
As title, I want to find the watershed area, but using QGIS.
I have following files to work with：
stream network shapefile(polyline)
point shapefile clipped from the polyline shapefile
a whole ...
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27 views
GRASS - Creating an Attribute Based on Driving Distance
Is it possible to calculate the driving distance for each node of one layer (fire stations) to each node of another (address points)? After doing so, I need to sort all of the distances from shortest ...
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64 views
Grass won't import shapefiles
I have a problem involving the import vector data command, specifically importing shape files. I installed QGIS on a pc at work and there I could import shape files into GRASS GIS 6.4.3RC2 (which is ...
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1answer
123 views
QGIS contour lines shapefile to DEM help
I want to create a DEM from depth contours (shapefile) in QGIS. I've been trying to work out how to do this based on this previous question, notably from this link from that page, however I'm stuck, ...
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30 views
GRASS v.overlay.or Error when trying to split a polygon with a line
I am using the Grass plugin in QGIS for Windows (1.8.0). I am trying to split a polygon with a line feature. I am using the v.overlay.or function within the QGIS Grass plugin. I have the line layer ...
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2answers
47 views
contour lines from point shape attribute
I have a point shape file and one of the attribute refers to the altitude.
Is is possible to obtain a contour lines shape file in GRASS?
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63 views
SEXTANTE “could not load layer:…”
When I try to do a GRASS command via SEXTANTE in Qgis I always get the error:
"Could not load layer:...." check log file
Does not matter wether it should be saved in temp or another folder.
I found ...
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1answer
61 views
saga & grass configuration in sextante (ubuntu)
I have some trouble in running saga and grass algorithms in sextante. When I double click it appears a pop-up saying:
Missing dependency.This algorithm cannot be run :-(
This algorithm requires SAGA ...
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2answers
353 views
What's the relation between QGIS and GRASS?
I have been working with GIS and remote sensing in an university and professional environment some ten years ago (ArcInfo etc), so I have some experience even though somewhat outdated
Right now I am ...
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3answers
120 views
How to clean layers from non topological databases?
I'm doing my internship in a consulting office which is switching from MapInfo to QGIS/GRASS 1.8.0.
I posted here a few days ago about the way to clean a polyline from a Lidar data with v.clean.
...
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2answers
138 views
How to resolve missing Python module (importlib) for GRASS/Sextante?
I have installed the nightly build of QGIS 1.9 from Larry's Dakota Cartography site, and have downloaded the latest Frameworks from William's Kyng Chaos site.
However, I am unable to install the ...
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131 views
How to repair and clean contours from high data resolution (lidar)?
I'm unsuccessfully trying to make a bathymetric map with contours extracted from Lidar data at 1 m resolution.
The extracted contours have a lot of artifacts like dangles and islands.
First I used ...
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2answers
95 views
r.regression.multi - ERROR: Not enough valid cells available
I am running a few analyses with r.regression.multi in Grass 7. For a few rasters that I try to correlate, the following error comes up, however: "ERROR: Not enough valid cells available".
I cannot ...
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1answer
62 views
How to get started with GRASS shell?
I'm a beginner in programming but i have to work with GRASS at work, and do it quickly.
I'm completely lost with all the variety of tutorials that are existing and to me, don't look the same...and ...
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2answers
64 views
GRASS: populating attribute table with specific values
I have a vector map that includes 100 points. These points were created using v.extract to randomly sample a larger map of 10k points. As such, the 'cat' values range from 1 to more than 10k. What ...
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30 views
GRASS: shift point locations in a random direction
I have a vector map that contains 100 points. For each point, I would like to shift it 250 units in a random location. It's easy enough to shift all points in a specified direction using
v.edit ...
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38 views
Problem opening GRASS GUI: libgeos-3.3.6.so: cannot open shared object file:
I have been using GRASS to process some Landsat imagery but very recently, and as far as I am aware - after having done nothing different or changing the settings, I am trying to use GRASS and on ...
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1answer
27 views
GRASS GIS: red square around node topology information?
I've been using GRASS since 2005, but I cannot find an explanation to the square boxes that appear around the nodes of a lines layers, when I display topological informations on the map.
I thought ...
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63 views
HELP! Starting up GRASS - Error messages.
I am just trying to start using GRASS, but am having problems setting up.
This is the error message I get:
WELCOME TO GRASS Version 6.4.2 2012
1) Have at your side all ...
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3answers
234 views
Howto setup and use a remote GIS workstation (QGIS,GRASS,PostGIS)?
I'm using QGIS (and sometimes GRASS and PostGIS) on my 2009 MacBookPro for my thesis project.
I was wondering (during an endless batch generalizing in QGIS) if I can set up a server so I can work from ...
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22 views
query for adjacent polygons in GRASS?
i need to create a table of each district in india's adjacent districts.
i found this query but couldnt get it to work for me: SELECT p1.PK_UID, p1.Name FROM Polys p1, Polys p2 WHERE p2.PK_UID=1 AND ...
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1answer
129 views
How to reclassify a float raster?
I have three rasters which represent distance (in metres) from certain things (bus stops, parks, libraries). I would like to reclassify these rasters so that they get integer values based on the ...
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1answer
37 views
Full Easting and Northing coordinates values cannot be encoded in GRASS r.water.outlet in SEXTANTE-QGIS
The Easting or Northing coordinate parameter accepts only 5 digits. The Easting and Northing values for my outlet are 6 and 7 digits long (integer). How can they be encoded in r.water.outlet? Can ...
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1answer
92 views
Sextante grass folder incorrect?
What is the correct grass folder in Sextante? I alway get this message:
The specified GRASS folder does not contain a valid set of GRASS
modules. Please, go to the SEXTANTE settings dialog, and ...
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2answers
125 views
Grass 7 / ArcGIS 9.3 - tiff to raster
Again a Grass 7 question. I have the output of a modelling run as matlab file, which I can export as tiff and load as geotiff. OK - now can I extract the data/convert this tiff into a raster proper?
...
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48 views
Grass7 - r.regression.multi and new raster
I am on the learning curve with Grass7. I managed to make r.regression.multi work, but there is one thing that would be of high interest for me: it is possible to create a new raster showing the ...
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98 views
qgis plugin: “WindowsError: [Error 6] The handle is invalid”
OS: Windows 7 64bit
GIS: QGIS 1.8 (qgis.org/downloads/QGIS-OSGeo4W-1.8.0-2-Setup.exe)
path variable:
GISBASE=C:\Program Files (x86)\Quantum GIS Lisboa\apps\grass\grass-6.4.3RC2
...
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1answer
133 views
How to split line at a specified distance and getting coordinates of start and end points of each line segment？
I tried v.split in GRASS：
and my notebook ran a lot of time but showed this error：bad allocation, then I click "OK", and got nothing.
Are there other ways to split lines？and I hope to get 2 new ...
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1answer
90 views
import grass.script as grass under windows 7
OS: Windows 7 64bit
GIS: QGIS 1.8 (qgis.org/downloads/QGIS-OSGeo4W-1.8.0-2-Setup.exe)
I have created a plugin for QGIS, with the QGIS plugin builder.
Now i would like to import grass.script into ...
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67 views
GRASS Plugin to QGIS error
I am installing QGIS and GRASS as part of an FOSS GIS class I'll be teaching this summer. I used the OsGeo4W installer. This installer has always worked flawlessly for me except on the machines at the ...
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2answers
86 views
Handling MODIS NoData cells with gdalwarp
I'm using the gdalwarp tool to convert MODIS .hdf into GeoTiff files. I want to set the value of the nodata cells so that when I import the .tif image into Grass there is no black edge. I'm using the ...
