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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Undefined reference errors installing GRASS addon

I am trying to install the r.geomorphons GRASS addon (available from http://sil.uc.edu/pdfFiles/jarek/r.geom.zip) in GRASS. I tried on Windows but gave up and decided the best thing to do was to try ...
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138 views

extract data from several images to different shapefile columns using GRASS

I am now working in grass and I want to extract raster values from several images to a shapefile. I have already created the columns in the .shp where the raster values will be stored but I am facing ...
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55 views

Watershed other than stream ( between two points)

Is there any method available to demarcate watershed for a location other than stream? I mean, if I want to find out the watershed for a place, where no stream available but, sheet of water can flow ...
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230 views

How to apply v.transform on a set of vector layers (GRASS 6.4)?

I have 64 vector layers, all of them must be warped using the v.transform module; the pointsfile is the same for all vectors. How can I apply the transformation recursively to all layers? I'm not ...
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3k views

How to convert a regular point grid to raster? [duplicate]

Possible Duplicate: How to convert a point grid to a raster? I´d like to convert a regular grid (25 meter) of points (XYZ) to a raster. I have tried the GRASS-tool r.in.xyz but I always get ...
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960 views

Interpolation of contours (from one “main-contour-shapefile”)

I calculated, that the best and smalest possible äquidistance (equidistant) for my map is 30m. After I generlized my DHM, I extracted contours of a intervall of 30m and smoothed them. Now I have my ...
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455 views

mdenoise/r.denoise: How to

I want to use mdenoise / r.denoise but i cant get it working. I have Xubuntu 12.04 and Grass 6.4.1 GRASS tells me after installing the plugin: g.extension extension=r.denoise ...
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2k views

How to calculate the average value of a raster within polygons?

I am using the GRASS plugin in QGIS. I am trying to calculate the average value of a raster dataset within a set of polygons. I have created a new mapset and have imported both the vector and ...
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98 views

mapping number of days a site is flooded from daily inundated areas maps

I have a set of daily inundated area polygons and would like combine them into one map that can give me a map showing the number of days a site remained inundated. I am unable to figure out any ...
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440 views

Why can't r.patch find the rasters?

I have elevation rasters which loaded just fine in a GRASS session. They represent adjacent areas, so I want to meld them into one raster. I ran r.patch using the GRASS GUI, and it would only accept ...
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107 views

v.dissolve (and other scripts) not in GRASS path

I see that I have the v.dissolve module in my grass64/scripts dir, but it is not found in my path from the GRASS command line. I have the GRASS_ADDON_PATH environment variable set: ...
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116 views

How do I convert my coordinates to the limit of geographic region (outer edge)?

I am trying to use r.in.bin. The parameters of north, south, east, and west needs values: north=float Northern limit of geographic region (outer edge) south=float Southern limit of geographic region ...
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634 views

How to import .flt files into GRASS?

I am trying to import a raster file (.flt) into GRASS. The raster file (.flt) was generated from HEC-RAS. The said raster format cannot be imported into GRASS (it shows the error "file not ...
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623 views

Win7 GRASS 7 & i.landsat.toar

Hello has anyone got experience running i.landsat.toar ? The output files I get are empty, the command takes but a moment to complete. However when run in verbose mode all the calculations are done, ...
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245 views

The resulting maps from a r.mapcalc script is not computed properly

This post is a continuation of my other post Why is my controlling shell script not working?. I created another post because this contains a separate issue that I encountered with the same scripts of ...
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37 views

What's difference between Topology and Check Validity in QGIS?

I would like to know what the difference is between the Topology Checker and Check Validity tools? Is there anyone who knows of a good document or tutorial that explains functions of these tools? ...
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62 views

GDAL/QGIS broken Ubuntu 14.04

I think I've managed to bust GDAL after (I think) installing Grass7. I had previously built GDAL (1.10) from source with a bunch of additional drivers. When installing Grass7 GDAL 1.11 was installed. ...
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16 views

Creating input node file for V.net.salesman in GRASS?

I have imported line vector layer and point vector layer(12 points) to grass using v.in.ogr. Now i want to use v.in.salesman to find shortest path between these 12 points, but i couldnt input ...
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37 views

How to use r.mapcalculator to change values within a raster cost map to negative

I have created a cost map in r.cost module in GRASS (through QGIS). This is actually a distance map from a protected area and distance from protected area has been calculated in both directions. How I ...
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39 views

GeoTiff exported using GRASS will not open in other programs

I am trying to export an image group as a multi-band GeoTiff using the r.out.gdal module in GRASS. For some reason I cannot get ArcGIS to recognize my GeoTiff exports. I have tried opening the file in ...
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72 views

How to have newly added lines split existing lines where they intersect, using QGIS

I have a line shapefile where the lines form a closed polygon. Using QGIS (2.8 on OSX 10.7) I would like to add lines to the layer, basically splitting the polygon into quadrants. Then, I will need ...
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34 views

Duplicated vertices in contour features of GRASS?

I use GRASS to produce contours from DEM (r.contours for SRTM rasters). They looks fine, but most of the line features occures to be duplicated; i.e. verticies duplicated. Here are pictures of output ...
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67 views

What's the right way to calculate the scale parameter value for r.relief in GRASS?

I have a little doubt about the way I should calculate the value of the "scale" parameter in the r.relief command in GRASS. In the description section of the r.relief page of the GRASS manual I read: ...
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59 views

Old question without answer: R.Neighbors with large neighborhoods?

I'm working on the same theme as User 32882, and I'm new here. I have the same problem, and update his question with more details. Old question: "I'm running into problems running the r.neighbors ...
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80 views

G_realloc: unable to allocate 46320000 bytes of memory while managing large .xyz through v.in.ascii

I tried to convert large (~180MB) .xyz file into vector through v.in.ascii in QGIS Brighton (2.6.0) Grass plugin (it should be Grass version 6.4.3). The "primitive registration" stage lasted very long ...
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85 views

Trouble importing NumPy in GRASS. Architecture

I can't get GRASS to work on my system, and after doing some digging I think it is related to me using 64-bit python. I'm not really sure. I get this message... This module requires the ...
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167 views

How to visualize a point cloud in 3D with GRASS?

I'm new with qgis and grass so I'm sorry if there is a straightforward answer for this question but I can't seem to get it done. I've imported a pointcloud into qgis from a datafile. Now i'd like to ...
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59 views

Error in executing commands in GRASS GIS

I'm using Grass 6.4.3RC2. I have a problem because when I execute the command: r.radcov csv_file=cell_list_hataDEM_umts_amc_testTEST.csv dem_map-AlbSRTMdem@PERMANENT clutter_map=AlbClut@PERMANENT ...
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76 views

tutorial for deriving solar insolation estimates from high resolution Digital surface model

I want to estimate solar insolation using grass gis. I have a high resolution DSM generated from Large Format Digital camera.Being a novice in this field i Would like to have a tutorial and steps to ...
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37 views

How to change GRASS language within QGIS?

I use GRASS plugin inside QGIS on Japanese version of windows 7 x64. As I start GRASS tools, all the content show in English but when I try to execute a tool, tools option dispalys in Japanese ...
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101 views

Export GRASS raster as GeoTiff : nodata values exported as -nan (what happens in R?)

I am using the package raster to work with GeoTiff raster files which I expoerted from GRASS using r.out.gdal. GRASS assigned the value -nan to some raster files (type FLOAT32) for missing values. ...
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83 views

many add-on don't works GRASS 6.4.3

I use GRASS 6.4.3 on windows 7 64 bit. GRASS has been installed with QGIS 2.6.1. I have added r.stream.* adds-on by SVN. For each add-on, messages of installation were : OK. But when I try the ...
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66 views

i.landsat.toar doesn't Work With Band 6 of Landsat 7 in Grass 7

I'm facing an issue when running i.landsat.toar with a Landsat 7 image, here's the list of files: LE70010752014040CUB00_B1 LE70010752014040CUB00_B2 LE70010752014040CUB00_B3 LE70010752014040CUB00_B4 ...
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310 views

QGIS 2.6.1 Brighton/ Grass pluggin r.stream.xxxx

I just updated my OSGeo4W and now have QGIS 2.6.1 and GRASS 6.4.4 and am trying to get strahler stream order. I am figuring out GRASS 6.4.4 GUI by itself but GRASS is easier withing QGIS, however, I ...
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98 views

Use r.mapcalculator in Python console

I'm trying to use the r.mapcalculator algorithim in a python script, but I'm having problems in using the r.mapcalculator to tranform a raster layer with float values into integers. Using the ...
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22 views

adding new sensor

i want to add new sensor in grass. i followed the link http://trac.osgeo.org/grass/browser/grass/trunk/imagery/i.atcorr/README and created the .csv for our sensor.but where should i incorporate this ...
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237 views

How to create a mosaic in QGIS with cutline and feathering for Landsat-8 imagery

1 - I have two scenes Landsat-8 RGB 6/5/4 and I need to mosaic them: 2- This is my cutline in polygon format that will smooth the overlapping area: 3 - So, I need to create a mosaic with ...
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76 views

Only run r.neighbors if cell meets criteria

This is my first time using GRASS to work with Rasters, so please excuse my lack of knowledge on the subject. I want to run the GRASS r.neighbors function on cells that meet a specific criteria, ...
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35 views

How to add grass64 to PATH variable

I recently installed GRASS 6.4 in a Unix environment. The application opens fine, but I would like to also be able to run the GUI from the command line. The tutorials says that the grass64 command ...
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205 views

Running GRASS functions in QGIS 2.4 from python console

I am using qgis 2.4 and i am looking for the "easiest" way to execute e.g. the r.in.gdal function from the python console in qgis. Specifically for r.in.gdal, I could not found this function in ...
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51 views

Change QGIS Processing (Sextante) default arguments for r.out.gdal

Lately I've been using r.grow through the QGIS Processing Toolbox on several rasters which represent the whole world with 500m grid spacing. It takes many minutes to save the output. The reason seems ...
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99 views

Error importing raster into GRASS plugin in QGIS

I am trying to import a tiff raster file into GRASS however every time I do this the below error message comes up. I am using a custom CRS so I have tried changing it back to the default CRS but still ...
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60 views

Import shapefile into GRASS in QGIS

I am using the GRASS interface in QGIS 2.4. I have successfully imported my shapefiles into GRASS using v.in.ogr, but when I try to then use a GRASS tool, like v.net Network maintenance, the select ...
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36 views

Cost Surface No sense Results. GRASS

I have some doubts with the generation of a cost surface with r.walk of GRASS. It's assumed that the resulting layer is measured in seconds, but when I try to convert seconds in days march (6h per ...
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563 views

QGIS GRASS Missing Dependancy

I want to perform a view shed analysis in QGIS using GRASS 7 r.viewshed. When I double click on r.viewshed in GRASS GIS 7 commands in the processing toolbox of QGIS I get the following message: ...
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298 views

Loading GRASS gives error installing QGIS Chugiak on Windows 8.1?

I am experiencing a problem installing QGIS 2.4 Chugiak on Windows 8.1, resulting in a error loading Grass. This may be a problem only affecting certain installations, I'm not sure. I am a noob on ...
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19 views

Is my code for changing the resolution correct?

I have a raster files of daily minimum temperature (tmin) for the period 1962-2011 at a resolution of 1.125. I need to convert each single day raster file into 0.5 using inverse distance ...
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70 views

How to modify existing grass gis tools and run them in QGIS?

I would like to take an existing tool of the grass tool box and modify the code to the specific needs of my task. As I´m struggling to start some kick-off would be great. How to access code? What do I ...
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146 views

Empty signature file after i.gensig in GRASS

I'm trying to make a supervised classification in Grass 6.4.3 under Linuxmint 16. After digitizing the training areas, I transformed them from vector to raster. Then I've done the following: just in ...
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115 views

GRASS GIS: auto-completion fails in commande line

I'm running GRASS GIS 6.4.3. on Win 7, SP1, 64 bit. The path to my grass-DB is: D:\grassdb Within the GRASS GIS Commande Line, if I press the tab-key to auto-complete only folders, files and ...