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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Error using Grass v.clean

I am trying to clean topology of a TAB file in QGIS 2.14.4 and it returns an error message as below The weird thing is, I am able to execute this okay on my machine but not my colleague's. The other ...
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8 views

calculate watershed area for many points

Is there an efficient way to calculate the watershed area for many points using GRASS without looping through all points? My points lie anywhere on the stream segments not just at the junctions. This ...
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18 views

2D raster to 3D raster conversion problem “r.to.rast3” at GRASS GIS

Although I give the r.to.rast3 command and the program gives a success report, the output 3D raster is not seen at the map display window when I select 3D view. Why does it happen?
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37 views

Resolving geometry errors in QGIS

I have a shapefile where the geometry is a mess, lots of gaps, slivers, and holes. I need to correct these geometry errors, but I am having trouble with the process. I have read the pages here, here ...
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14 views

GRASS dependecies issues in Windows QGIS (i.vi for instance)

I have QGIS (2.14.3) and GRASS (7.0.4) desktop installed on windows 7 and have successfully installed the "GRASS" plugin in QGIS (using plugin manager). However, some of the GRASS dependencies, such ...
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12 views

Advice on which open-source GIS program to choose for object oriented feature extraction [on hold]

I need to extract polygon features from a series of raster images I have. I think that object oriented feature extraction might be the way to go, i.e. segmenting the image, and then doing an ...
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19 views

GRASS 7.3 r.fill.dir Does Not Create Output Raster

I am running GRASS 7.3 on Mac OS X El Capitan (2.9GHz, 8GB RAM). I have had to disable SIP in order to run it, but it works. I am hoping to perform some hydrological analyses on a few DEMs. My DEMs ...
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1answer
30 views

How do I connect my Python script external to the Grass GIS 7 program in Windows 10?

I've tried to find resources online to link and run my Python script externally from Grass GIS 7, however, I have not been successful. I found resources here that provide instructions (e.g., https://...
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37 views

QGIS GRASS: Error when converting vector to raster

I am trying to convert a vectorial layer (a grid of regular points with values, representing probabilities, associated to each point). I tried to use QGIS, but I got this error: ERROR 1: Attempt to ...
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16 views

AniMove error “Wrong value for parameter GRASS7 folder”

I installed animove in QGIS 2.14, then I go to Processing -> Options, Under the Providers section find Animove, Under Animove check Activate. I do this and then press OK. Error message "Wrong ...
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18 views

Add r.null functionality to GRASS toolbox algorithms in QGIS

I'd like to be able to use GRASS's r.null operation in the QGIS processing toolbox (not via the GRASS plugin). However, it doesn't seem to be available. How would I go about adding code to allow for ...
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1answer
32 views

Grass GIS messed up projection

I needed to load a shape in GRASS GIS to use the v.clean.snap function. The .shp was first viewed in QGIS, projected in 3857 or 4326, I don't remeber. After the adjustments in GRASS GIS I exported to ...
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16 views

Does the random number generator used by v.random return duplicates?

Using v.random, r.random, etc., can the same sight/location be selected? Meaning, can a location show up more than once?
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1answer
93 views

QGIS 2.16 GRASS geoalgorithms don't work?

I have problem again almost like version QGIS 2.14. I did not solve the problem. QGIS 2.14 GRASS geoalgorithms don't work? I install C:\MinGW and now QGIS grass geoalgorithms don't work? There is ...
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21 views

SPOT 1 HRV Atmospheric correction in GRASS GIS 7 returns NULL values

I'm having trouble using i.atcorr in GRASS 7. I am using 3-band SPOT 1 HRV image (Green, Red, NIR bands). Performed the i.atcorr for each band using the 6S parameters below (last parameter changed ...
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1answer
24 views

importing files from grass mapset to QGIS Layer Panel

I am performing an NDVI calculation against 2 sets of rasters. One produced by LANDSAT5 the other by LANDSAT8. r.mapcalc "L8_NDVI = float(L8Band5 - L8Band4) / (L8Band5 + L8Band4)" The L8_NDVI file ...
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2answers
21 views

Problem with r.grow.distance on GRASS

I would like to use r.grow.distance on a raster map. I rasterised a shapefile (about 50 cities in a region) and we can see them on the raster map. Yet, when I launch r.grow.distance, I have a ...
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1answer
11 views

r.statistics throws invalid reclass rule error despite assigning null to unique value

Trying to run r.statistics on two raster layers, one a layer of distinct zones produced via r.clump (stands) and one a layer of all ones (ones). The areas outside of the immediate region of interest ...
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1answer
20 views

r.fill.dir blocked

I am trying to fille a DEM downloaded by Geobolivia http://geo.gob.bo/. The r.fill.dir module in QGIS/GRASS toolbox blocked few minutes after I launched it for the DEM. It is very strange as, for ...
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1answer
17 views

geology problems: three-dimensional fault line - r.plane (GRASS) from polyline

I should use the r.plane script (GRASS) but imputing a polyline (trace of my fault line) and not a point; is this possible? I could use batch process, but I should be charged a lot of points and then ...
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15 views

Resolution changes when exporting raster from GRASS to Arcmap

I have a raster file of rainfall (floating) in GRASS that I want to export and open in arcmap. If I look for the raster file in GRASS, it has Rows: 140 ...
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40 views

GRASS on QGIS is generating new CRS

I am experiencing a strange problem by using the GRASS toolbox on QGIS 2.14.3 Essen. Even if in settings>options>CRS I select to use the project CRS when creating new layers, the results of GRASS ...
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1answer
9 views

How to change / switch mapsets in GRASS using cmd

I am using GRASS 7.0.4 I have created a new mapset to the LOCATION using cmd in it. But unable to switch back to old mapset. can anyone guide me??
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GRASS v.net.iso does not include all lines

I want to define catchment area for bus stops in small city. As a result of v.net.iso in QGIS with GRASS I don't get all highways in that city. Here are my steps: importing above layers into GRASS ...
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17 views

How to obtain accumulation map from r.stream.extract

I would like to obtain the accumulation map that is produced within r.stream.extract when extracting streams and then use it as input for r.stream.order (as described at the man page of r.stream.order:...
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113 views

How do I Spatially Partition a whole lot of points?

I have location data of customers, with over 130 million records, spread all across the country. This is a Spatial Table in PostGIS I want to now partition the entire country into 'service areas', ...
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1answer
28 views

Run processing (GRASS) algorithm as administrator

I am trying to use GRASS algorithms in a plugin of mine, in order to improve the quality of a shapefile containing lines that will be used as a graph later. The first algorithm I want to use is the ...
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23 views

grass algorithm changes integer to fixed length

using grass v.clean in the graphical modeller it changes all integer values from the original file to int with length 9 Is this a standard behaviour? Can this be avoided? The details of the grass ...
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1answer
33 views

GRASS Toolbar for QGIS missing the tools I expect to see

I am trying to learn GRASS and QGIS using the instructions here: https://docs.qgis.org/2.6/en/docs/user_manual/grass_integration/grass_integration.html. I am running on Windows and open the version of ...
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2answers
27 views

GRASS iterate over multiple shape files using g.region

I have a shapefile called Ahmednagar. I have daily rainfall data from 1997 till 2008. I want to sum total rainfall from 152 till 273 day for each year for 1997 till 2008. This is how I do it. g....
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138 views

Grass tools not working in QGIS 2.14.3-ESSEN, OSGEO4W

Windows 10 QGIS 2.14.3-ESSEN OSGEO4W install (current) 64-bit Processing toolbox. Grass tools do not work Neither 6 nor 7. 6 makes sense as I do not see OSGEO4W installing it but 7 tools are ...
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26 views

Comparison of % change in two photos with GRASS

I have two aerial photos of the same location taken at two different dates. Is there a way to compare the % difference between those two images using GRASS or is there a better tool? Sorry, also if ...
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1answer
33 views

Fast, simple assignment of flow directions to flats in GRASS

I have some enormously huge DEMs which I'd like to assign flow directions to. These DEMs are guaranteed to have no sinks, just flat areas. It seems as though the only ways of assign flow directions ...
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1answer
74 views

Stratified Random Sampling Tool

Is there a way to produce a certain amount of random points over different classes in a raster in QGIS? I have extensions such as GRASS or GDAL, ...
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1answer
38 views

GRASS/QGIS- “buffer” created with DEM analysis- how to avoid it?

I have, to start, a DEM raster and a shapefile, with random created points, within a given polygon. The DEM raster was clipped with that same polygon. With the DEM raster, I used GRASS to perform ...
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1answer
46 views

Exception using PyGRASS: “No module named 'core'”

I am trying PyGRASS on Ubuntu 14.04. I have GRASS 7 installed from the UbuntuGIS PPA: $ dpkg -l | grep grass ii grass 7.0.4-1~trusty1 ...
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2answers
61 views

GRASS 7 environment setup for Python

I would like to use some GRASS functionality from a Python programme. With GRASS 6 this required the set up of various environment variables, as detailed in the GRASS Wiki. I am trying a similar ...
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1answer
21 views

CRS different after r.reclass through QGIS different than source raster

According to the properties, my output raster is in a different projection than the input after running GRASS r.reclass through QGIS. Does anyone know if this is just a fluke and I can simply select a ...
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1answer
21 views

System locale settings error creating GRASS location from Python

I am trying to use GRASS 7 from Python without explicitly creating a location. I am starting with the script provided at the GRASS-Wiki. This script tries to create a new location in the /tmp/ folder ...
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35 views

Setting up a simple catchment area for shops using QGIS?

I would love to set up a catchment area around simple dots on a network map. The catchment should be separated by different range-areas (50, 100, 200m), just like isochrones. I tried the GRASS plugin ...
4
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1answer
132 views

v.kernel is missing under Processing Toolbox GRASS GIS 7 commands

I installed the QGIS Standalone Installer Version 2.14 (64bit), that automatically contains GRASS 7.0.4. I created a map with several layers and rasters in the program called QGIS Desktop 2.14.3 with ...
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11 views

Importing TRMM bin data in GRASS

I am trying to download daily data from TRMM from this website ftp://disc2.nascom.nasa.gov/data/TRMM/Gridded/Derived_Products/3B42_V7/Daily/1998/ For example, If I download any .bin file from the ...
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1answer
22 views

What causes the comand 'd.vect map' to fail in GRASS-GIS?

I have been having problems with visualizing my data in GRASS-GIS. I imported my .shp file into the software following all instructions and, after that, I selected the layer I wanted to visualize. ...
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54 views

Multiple watershed delination with QGIS

I am trying to divide a DTM model in subbasins but I have set specific outlet points for the subbasins, and not to use a thershold. Is there a tool similar to r.water.outlet but with multiple outlet ...
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2answers
90 views

QGIS Can't run any GRASS tools from processing toolbox

MAC OSX 10.11.13 New machine clean install of QGIS from Kyngchaos Installed Current version 2.14.2-Essen When I try to run a GRASS command e.g. v.clean I get the following error: This algorithm ...
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41 views

cellinp and cellout in v.vol.rst

I am trying to use v.vol.rst in Grass 7.0.4 to interpolate temperature values considering elevation. The answer of Grass to my attempts is: WARNING: Unable to create cellout raster map without cellinp ...
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1answer
51 views

Error in r.thin Qgis GRASS : Input raster must be of type CELL

I am getting the following error from QGIS GRASS GIS r.thin module ERROR: Input raster must be of type CELL. The input file is a simple file of 0 and 1 that represent a drainge network. I obtained ...
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25 views

How to install r.mcda.electre on GRASS

I have downloaded r.mcda.electre addon from the following link: https://wingrass.fsv.cvut.cz/grass71/x86_64/addons/grass-7.1.svn/r.mcda.electre.zip But I can not install it with the latest version ...
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36 views

Negative values in r.watershed flow accumulation

I am trying to process a DTM by using r.watershed in QGIS 2.14.3, with the GRASS GIS toolbox. It should be the file named: "Number of cells that drain through each cell". I get some negative values, ...
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26 views

Downloadable pdf format of GRASSGIS 7.0 manual [closed]

Can anyone help with a link or something that could enable the download of a pdf version of the grassgis manual? I am having a hard time trying to convert the html version into printable pdf. Nkeze