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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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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60 views

Empty signature file after i.gensig in Grass (SOLVED)

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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31 views

r.composite gives blank image output in GRASS GIS

While running r.composite in GRASSGIS GUI command the image formed looks absolutely blank. The data I used is listed here below. IRS-LISS III Multispectral coverages. (i.e. band 2, 3 and 4 for Blue, ...
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378 views

“Missing dependency.This algorithm cannot be run :-(” QGIS + GRASS Windows 7

Windows 7, OsGeo4W pack installed including QGis 2.4.0 and GRASS. I Qgis when i try to execute a GRASS geoprocessing algorithm i get this popup: "Missing dependency.This algorithm cannot be run :-( ...
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33 views

Help me to understand how i.fusion.brovey works in Grass 6.4.3

I'm using Grass 6.4.3 in Linuxmint 16. I don't have a very big problem but I'm trying to understand what is Grass doing, if I'm applying the process correctly and if there is something wrong with my ...
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58 views

r.topidx error: required parameter output not set

I'm calling GRASS r.topidx from QGIS 2.2.0. I can get other tools to work on the DTM, for example r.watershed. But r.topidx I get the Oops message: Oooops! The following output layers could not be ...
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21 views

qgis: module crashed or killed

using Grass 6.4.3. via Qgis 2.2.0 Valmiera (standard installation package): Why would Grass modules suddenly produce a "module cashed or killed" error. specifically in relation to r.surf.idw2 and ...
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56 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 ...
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35 views

GRASS workflow for volume calculation

i am attempting a volume calculation using the route of 2 dems (upper and lower) and trying to subtract the difference. workflow as follows: A. rasterise vector contours (v.to.rast.attr) B. create ...
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24 views

QGIS GRASS vector simplification creates duplicate data rows

When simplifying polygons in QGIS (2.2.0) with the GRASS v.generalize tool the resulting layer duplicates some data rows many times. A shapefile of 657 zones/data rows: .. is simplified to one ...
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57 views

Background (sky/terrain) of a viewshed

Is it possible to determine whether a point feature of a particular height would be backed by sky or by terrain? I've done the viewsheed analysis of a wind turbine. Now I would like to make a raster ...
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45 views

Error G_Calloc v.to.rast

Using the grass GUI I get this error message: ERROR: G_calloc: unable to allocate 2004389888 * 8 bytes of memory at raster.c:71 What can i do to remedy this?
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132 views

How to use python to set a variable to a value from a vector attribute table for GRASS

I'm adding to a python script for GRASS v.transects.py. I want to set a variable to equal a value from a field in the vector's attribute table using a for loop to cycle through each row. This is one ...
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44 views

GRASS raster map types: UInt16 and Float64

i am in the processing of using r.out.gdal to export DEMs from GRASS into QGIS this is the output of the first try: using UInt16 as the data type. r.out.gdal input=DEM0maslTopog@UTM_35S ...
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21 views

problem r.walk region GRASS

I'm getting troubles to run r.walk. If I run r.walk in this region: projection: 3 (Latitud - Longitud.) zone: 0 datum: wgs84 ellipsoid: wgs84 north: 33:39:03N south: 29:16:03N ...
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28 views

can grass modules work separately

Grass is very useful tool for pre processing of imagery.i want to use i.atcorr module separately.will it be possible. i have compiled using .cpp files(AerosolConcentration.cpp, ...
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40 views

Use python to execute GRASS module v.distance

I have successfully use python script to import a line shapefile and a point shapefile into GRASS, and the following are their attribute table in QGIS, line shapefile point shapefile Now I want ...
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155 views

libgdal1 and libgdal1h conflict

I am on Ubuntu 14.04. When I am installing PostGIS-2.1, it's asking for libgdal1 library. But when I am installing libgdal1, it's removing grass and gdal. Can someone please guide me how to install ...
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107 views

QGIS GRASS plugin missing!

I just installed QGIS version 2.2.0-Valmiera on my mac with OS X. First I installed all required frameworks. QGIS is running, but the Grass plugin is not existing. In the toolbox the grass tools are ...
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109 views

QGIS 2.2.0 GRASS not worked

I use QGIS 2.2.0 on Windows 8 64 bit. I try to install use Standalone installer and OSGeo4W and still get the error And then i start GRASS C:\Program Files (x86)\GRASS 6.4.2>grass64 ╬╪╚┴╩└: ...
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30 views

GRASS GIS 3D - Inconsistent number of attributes

I am trying to automate my 3D plotting of GRASS GIS 7 results, also to make them more consistent in size and view angles. So for m.nviz.image elevation_map=DEM -a mode=fine resolution_fine=1 ...
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22 views

QGIS GRASS plugin: r.composite quality loss

When using the r.composite tool within the GRASS plugin in QGIS, the result raster has a cell size of 150x150 while the input rasters have a cellsize of 30x30. Can this be overcome somehow or is this ...
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36 views

GRASS GIS v.in.ply

I'm trying to import a .ply file from MeshLab 1.33 into GRASS GIS 7.0 using v.in.ply addon, but I get the error message: ERROR: List index must be integer, is uchar This appears to be referring to ...
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23 views

Run this module in GRASS 6.4.3 command line in Windows 7 or QGIS Grass Module

I have GRASS 6.4.3 running and working in windows. I would like to use this script (http://grasswiki.osgeo.org/wiki/AVHRR) Scroll down to Import to see the code. I have the correct EPSG set but ...
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41 views

Problems running grass.mapcalc

I am using the GRASS Python Scripting Library on Ubuntu 14.04 with the packages available from the Universe repository. I have the following block of code: try: ...
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91 views

Convert a mask image to polygon shape file using GRASS

I used image classification technique in GRASS GIS v7 and generated the image mask below in which white area has NULL value and red area contains 1. I am going to clip those red color areas in a ...
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58 views

Running a batch script in GRASS command line - v.dissolve and v.db problems

I have been writing a number of scripts for automating isochrone production in GRASS just using the command line. I create files with isochrone lines in them and then a buffer around each of the ...
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20 views

r.series command in QGIS - timeseries

I am using r.series command in qgis. The command is performing correctly, but when I import input raster files, it creates a list in a random order. Sometimes the order of input rasters is essential ...
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57 views

QGIS r.cost / r.drain and errors

I'm trying to find the optimal route of several archaeological sites with Qgis 2.2. I've a DEM and r.walk or r.viewshed executed successfully, but r.cost always fails creating the output, however ...
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42 views

time processing

I am computing NDVI for Landsat TM in grass 6.4.3 in raster map calculator, and time processing is many hours and finally tke message is "failed". trying to find a solution I discovered that it ...
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83 views

r.viewshed - Can't find with Grass toolbox

I'm trying to use r.viewshed and have got Grass installed but can't find it anywhere! under toolbox, I click 'Grass commands (152 geoalgorithms) and have a choice of imagery, raster, vector, etc, ...
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20 views

Changing tracks to vectors in a grid

This is a version of a question that I posted on the GRASS list, but I didn't get any suggestions there. I would like to overlay a grid (cell size about 500 m x 500m) over an animal track created from ...
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31 views

R equivalent of GRASS r.grow?

What is a good R equivalent of the GRASS function r.grow? The closest I've been able to find is the script suggested by whuber in response to Creating randomly shaped clumps of cells in a raster from ...
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38 views

v.buffer angular buffer doesn't take all the polygons into account

I am trying to create an angular buffer around building footprints with the v.buffer command (QGIS 2.2). There is no error message, but the algorithm doesn't take into account all the buildings. This ...
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66 views

List the projection & datum of all the files in a folder

In QGIS/GRASS, is it possible to list the projection details of all the shp,tab,dxf files in a folder ? We are having 100 - 150 files in too many folders. We would like to create a table of Proj ...
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21 views

Is it possible to compile a grass addon into a commandline app?

As the title says, I'm wondering if it's possible to take the source of a grass add-on and compile it into a commandline app. Or, alternatively, use the add-on in a python program. Basically, I ...
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23 views

How to make DTM Qgis-grass

Good evening, I need help. Should I create a dtm of an area in the province of Vicenza. It 's the first time I try, I tried the tutorials on the Internet but I could not understand how to do it. Could ...
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151 views

GRASS “Argument list too long” with run_command

I have a python script that uses the grass.script.run_command function to read in, process, and export a bunch of raster files. On projects where I have a large number of rasters (>1,000), it fails ...
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84 views

how to mosaic rasters in grass gis?

I am new user of GRASS GIS. I need to know how can i mosaic different satellite imageries using GRASS GUI? I was trying to use i.image.mosaic, but could not succeed. I have been looking for online ...
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91 views

Is it possible to use polygons to create heatmaps?

I hope I can explain my question clearly, so here it goes: I've been fiddling around with heatmaps on QGIS for a few days, but came across a small obstacle on my way. I have a dataset comprised of ...
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93 views

import parameters for r.watershed - (watershed basin analysis program) tool from grass using Qgis 2.2

I want to run this tool from Qgis 2.2 but i don't know how to use the PARAMETERS to run this tool. The red frame are the PARAMETERS I don't know. Can someone to tell me what those PARAMETERS are ...
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1answer
123 views

georeference and orthorectification of aerial photos

I am trying to process photos taken with a tetracam ADC micro camera placed on a UAV. I have GPS coordinates and mavlink logs providing roll, pitch and yaw of the UAV. I am having a real hard time ...
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136 views

Matlab script - how to access from/run in GRASS GIS?

I am currently working on shell script in GRASS GIS and Ubuntu. At some point, I must run a calculation (based on an ascii grid) that I have available as Matlab script and .exe (created from Matlab I ...
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67 views

Error “Unable to open data source” - import .shp into GRASS

I'm new to GRASS and GIS in general, so please forgive my ignorance... I have problem with loading Vector Data (.shp) into GRASS I used the following steps 1.1. and 1.2: ...
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20 views

External scripting in GRASS libgrass_grass.6.43.dll not found

I need to run interpolation through GRASS through a script such that its requires no user interaction in the process and the interpolation raster output can be used for display in HTML Web Page. To ...
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26 views

nr of cells between cells

I want to do the following: I have a set of cells with the value 1, and a set of values with 2. I want to calculate for each cell [2] the distance - ideally number of cells - to the nearest cell 1. ...
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49 views

GRASS GIS using a loop with r.neighbors command

I'd like to do a trend analysis with ndvi data from 1982 til 2005. I am using the r.neighbors command to get first the spatial variance (then I would use r.series method=slope to get the actual trend) ...
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17 views

GRASS module r.fitpoly

I need to calculate the average daily temperature for each month. As an input I have 5 .asc grids for 6, 9, 12, 15, and 18 GMT for each month of the year. I was wondering if there is a predefined ...
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37 views

Extrude polygons with holes in GRASS using v.extrude

I have a shapefile with building footprint polygons. Many of the polygons have holes/inner rings within them (I'm not sure of the correct term in Grass). These import correctly into Grass GIS. I aim ...
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35 views

grass - add on problem

I can't install the addon in grass 6.4.3 to my linux mint. i've already installed the SVN and than it says: GRASS 6.4.3 (fabian_idrisi):~ > g.extension r.fuzzy Fetching from GRASS-Addons SVN (be ...