Questions tagged [qgis-grass-plugin]

QGIS pluging which provides to access GRASS GIS databases and functionalities

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QGIS Grass Raster import using r.in.gdal.qgis: 'Layer data source could not be found'

I'm a QGIS learner following the official QGIS Training Manual. I'm on Module 12.1. My problem is that when I try to add a raster layer to GRASS using r.in.gdal.qgis, the resulting layer shows a red ...
JnomiddlenameHoward's user avatar
1 vote
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GRASS paths in Python standalone from QGIS install

I am trying to access GRASS from Python (Spyder). I have: Installed via pip install grass-session Started GRASS from OSGEO4W, loaded the mapset and location Started Spyder from Anaconda Tried to ...
william3031's user avatar
1 vote
1 answer
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Add -c flag to v.surf.idw call from PyQGIS?

This code is part of a plugin I created. MY QGIS version is 3.28, my GRASS GIS version is 7. rasterized = processing.run("grass7:v.surf.idw", { 'input': points_vector_layer, 'npoints'...
Noxy's user avatar
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Install QGIS with the GRASS plugin enabled in a conda environment?

I am having issues using the GRASS plugin in QGIS in a PyQGIS script. I used miniconda on Ubuntu 20.04.6 LTS to create an env with QGIS using conda commands: conda create -n qgis_test conda activate ...
Cicatrixx's user avatar
  • 131
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1 answer
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QGIS Raster resampling without label changes

I am working on raster data that which is in a 5x5 meter resolution. I need to resample this to a 25x25 meter resolution. I have used resample.stats which works, but changes the label numbers into one ...
Hartje's user avatar
  • 133
1 vote
1 answer
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Missing tool `i.points.auto` in the QGIS GRASS provider

I have the latest version of QGIS 3.32.2-Lima installed. I have installed GRASS 7.8 and 8.3, which is confirmed in OSGeo4W. GRASS plug-in is enabled in QGIS. But I cannot find the i.points.auto tool ...
Comrade Che's user avatar
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2 votes
1 answer
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Extracting values from HTML file into the QGIS Graphic Modeler

I've built a little model which does a simple linear regression between values of a point layer and a raster. The model works fine, but I cannot find a way to extract the regression coefficients (a ...
farmgis's user avatar
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Issue with compilation of rdenoise for GRASS

I would like to use r.denoise an external tool of GRASS. So I tried to install it following instructions from this page r.denoise manual But the terminal returns me an error during compilation: ...
Tim's user avatar
  • 83
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Calculating r.li.shannon with vector grid on GRASS GIS

I looked up baker and cai (1992) and throughout the internet to find my answer, but my novice level makes it hard to find concrete solutions. I am trying to calculate the shannon diversity index (r.li....
erdbee's user avatar
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g.gui.rlisetup configuration file missing

I am trying to calculate the shannon diversity index (r.li.shannon) for a landscape using the r.li tool in GRASS GIS 7.8.7. My input file is a raster of my different land covers with an assigned ...
erdbee's user avatar
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R.regression.multi land-use data not enough valid cells

What I want: run r.regression.multi between land-use change and bumblebee occurrence. What I did: X coefficients: cov_all.0 of North, East, South and West SSP1 -4 layers in total. (I projected the ...
kar-g's user avatar
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How is the r.walk.points module supposed to work in QGIS?

So I have an elevation layer, a friction cost layer and a shapefile for the starting points. I have tried to run it with different parameters and it keeps giving me error messages like the ones that ...
Nickmofoe's user avatar
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1 answer
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Removing gaps between line features with v.clean in QGIS

I want to fill gaps between line features with v.clean. It works for the small gap (0,015m) but the 10-meter gap will not be closed. These are my parameters: Test available here: data shapefile
Barrylim_work's user avatar
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GRASS tools on QGIS unable to open data source from Onedrive

Every time I run GRASS tools on QGIS, where the data source is located on Onedrive folders, I always receive this error "ERROR: Unable to open data source <C:\Users....>". When I move ...
May0123's user avatar
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QGIS v.net.salesman generates error when restricted to selected features

I'm using the GRASS v.net.salesman in QGIS to find the shortest route between some American colleges on the road network. The network layer comes from Natural Earth Data, specifically ...
Lee Hachadoorian's user avatar
10 votes
1 answer
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GRASS and SAGA do not appear in QGIS processing toolbox?

I installed the latest version 3.24.1-Tisler and also installer GRASS 7.8.7, SAGA 7.8.2 and PCRaster using OSGeo4W (from 7.4.2022). All Plugins have been activated in QGIS as well as the settings in ...
WeRoIT's user avatar
  • 101
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0 answers
47 views

Which band of colour does r.reclass use?

I have been trying to use the r.reclass tool edit my raster layer. So far it works as I use command such as 0 thru 100 = 1 and it works. However, as my raster layer has multiple colour bands (RGB), I ...
Sherry Wu's user avatar
3 votes
0 answers
615 views

Installing a GRASS addon in QGIS

I am trying to use the GRASS addon r.vector.ruggedness in QGIS, but it is not available. Then, I downloaded GRASS directly and there it is possible to download the addon that I want. Nevertheless, I ...
Jose Diaz Ramos's user avatar
2 votes
1 answer
672 views

Selection of best site for factory in QGIS

I am stuck trying to determine, where it would be preferable to locate one or more factories according to the data shown below. The criterias for the selection of the site(s) are: There must be 15 ...
MadMagister's user avatar
1 vote
1 answer
848 views

Tools from grassplugin does not work in QGIS 3.22.2

I have a problem with the grassplugin in QGIS 3.22.2 Białowieża. When I try to use the v.net.alloc (and other grass-tools) from the Processing Toolbox in the standalone QGIS 3.22.2 I get this error: ...
MadMagister's user avatar
0 votes
1 answer
338 views

Cannot create new mapset in QGIS 3.4.6

I activated the grass 7 plug in, but get the following error: GRASS intit error: GRASS was not found in 'C:PROGRA~1/QGIS3.4/apps/grass76' (GISBASE), provider ans plugin will not work. I also cannot ...
Danni's user avatar
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3 votes
1 answer
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Field name for stats to be calculated not appearing using v.vect.stats

I'm trying to calculate the average value for an attribute of a set of points that fall within a set of polygons using v.vect.stats from GRASS. I've checked the attribute table of the point layer ...
pbreach's user avatar
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2 votes
0 answers
477 views

GRASS init error when adding GRASS as Plugin in QGIS 3.18.2

When I add GRASS from a list of Plugins, I receive an error: GRASS init error: GRASS was not found in 'C:/PROGRA~1/QGIS 3.18/apps/grass/grass78' (GISBASE), provider and plugin will not work. ...
Mat's user avatar
  • 21
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0 answers
993 views

QGIS issues on Mac OS Big Sur 11.2 GRASS and SCP issue

I have been having issues with QGIS on my Mac. The current operating system is Big Sur 11.2. The current workaround to the SCP plugin is to revert back to version 6 via these steps: https://...
Rachel's user avatar
  • 143
3 votes
2 answers
5k views

How to use v.clean in QGIS to fix polygon topology

I have QGIS 3.18 Zurich with GRASS 7.8.5 installed on my 64bit Windows machine. I have digitized 1600+ polygon boundaries that now have sliver polygons, gaps, and overlaps which I've confirmed via the ...
BenW's user avatar
  • 613
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2 answers
348 views

How to output 3d geometries via grass plugins v.drape, v.to.3d in qgis?

When I try to process either a 2d Linestring or a 3d MultilinestringZ vector through the v.drape or v.to.3d processing tools in qgis, I get an error stating that it is outputting a 2d geometry instead ...
jamierob's user avatar
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2 votes
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316 views

QGIS: GRASS GIS plugin not accepting UTM point coordinates

I am using QGIS 3.16 with the GRASS plugin. I imported a UTM point cloud (x,y,z) and successfully generated a TIN surface based on it (using QGIS own functionality). But when I want to use GRASS v....
matt77's user avatar
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-1 votes
1 answer
65 views

Create GRASS 7.6 environment in PyQGIS [closed]

I am working on PyQGIS in QGIS 3.10 (Windows). My goal is to create a GRASS environment to be able to run modules like r.in.gdal among others. but i can't find the way to execute the modules. I have ...
Manuel Guerra's user avatar
0 votes
1 answer
232 views

I am running a processing PyQGIS script with grass i.pca but I am not getting results in my output folder

It runs without problem but I don't get the expected pca bands, my output folder is empty, I don't know what to test. path ='C/Users/Manuel/Documents/INPUT' output='C/Users/Manuel/Documents/OUTPUT' ...
Manuel Guerra's user avatar
2 votes
0 answers
43 views

QGIS Grass-plugin output does not match the CRS of input files nor project CRS

My project CRS and raster layer are EPSG:31467. However, when I use for example r.to.vect to create a polygon from the raster, the created vector layer has an unknown CRS and is a little bit off (does ...
Konstantin_o's user avatar
4 votes
1 answer
317 views

Using GRASS and v.split with QGIS

I have been working with QGIS for a few years now and am just now having issues with the GRASS module. Ultimately, I am just trying to split a line (river) into 100m segments, and have found the ...
Joe Lemanski's user avatar
1 vote
2 answers
158 views

QGIS GUI showing nothing on loading a GRASS mapset

I have GRASS 7 plugin installed with QGIS 3.4.2. I downloaded the Alaska QGIS sample dataset and followed these steps to load the dataset into QGIS. When I expand the alaska location and load the ...
Nancy's user avatar
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1 vote
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207 views

How do I split polygon into line segments?

My question exactly matches with this one : How do I split polygons into line segments? but the solution is outdated, I am not able to find v.type.bl option under the grass dropdown in QGIS 3.8. ...
Sumit Singh's user avatar
2 votes
1 answer
282 views

QGIS GRASS using v.drape FileNotFoundError: No such file or directory: '/usr/local/Cellar/osgeo-grass/7.6.1_5/grass76/etc/lock':

I'm running QGIS 3.8.3 and am trying to use v.drape. When I run it from the processing toolbox, I get a FileNotFoundError that's pointing to a strange /usr/local/Cellar/osgeo-grass.... folder. I'm ...
hike734's user avatar
  • 69
0 votes
2 answers
500 views

GRASS: r.to.vect outputs empty layer when creating lines

I am trying to convert a binary raster to polyline using r.to.vect in QGIS 3.4. It keeps giving me an empty output, however. This is my input raster: And I am expecting an output (more or less) like ...
wfgeo's user avatar
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0 votes
0 answers
2k views

QGIS GRASS plugin not found?

I have seen this question come up before and have tried the related fixes as best as I could but nothing seems to work. I am running the most recent LTR of QGIS, 3.4.8 but my GRASS plugin cannot be ...
GM23's user avatar
  • 9
1 vote
0 answers
274 views

GRASS r.sun returns "ERROR: insol_time and incidout are incompatible options"

I'm trying to measure irradiance on a DEM using the r.sun tool in QGIS 3.6. I have grids for the elevation (EPSG:32735 - WGS 84 / UTM zone 35S), the slope and aspect (EPSG:4326 - WGS 84). I've tried ...
stephlynette612's user avatar
1 vote
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22 views

Inner workings of GRASS reclassification on QGIS. How does it work with multiband rasters?

I have a 33 band raster layer I need to reclassify. I tried using GRASS module inside QGIS and it worked out fine, except that it outputs a raster with a single band. Which band of the 33 did it ...
Eric Lino's user avatar
  • 394
3 votes
2 answers
698 views

Find radius of curve?

Using QGIS with GRASS I have found a route through r.drain but it has many sharp curve. the maximum radius of curve allowed to me is 176m. Is there any to reduce the curve sharpness to 176m or at ...
Bhupendra Singh's user avatar
4 votes
2 answers
1k views

GRASS not working in QGIS, standalone

*Running QGIS 3.6, GRASS 7.6; have both Python 2 and 3 I'm trying to run a GRASS algorithm in QGIS, and none of the GRASS tools are working. GRASS also isn't working in the standalone version. I have ...
jyingling's user avatar
  • 477
2 votes
0 answers
84 views

Do I need the standalone GRASS app if I have the GRASS Plugin and Processing toolbox enabled in QGIS?

What processing abilities does the standalone GRASS GIS application have that aren't available in the QGIS GRASS plugin/toolbox? I'm trying to understand whether you would need/want the standalone ...
ArchArchy's user avatar
  • 121
0 votes
0 answers
181 views

GRASS function "V.net.centrality" Error env: python3: No such file or directory

I am using QGIS 3.4 (just updated) on a Mac OSX Mojave 10.14. I am trying to use the grass function "v.net.centrality" but I keep getting an error. The error is ... env: python3: No such file or ...
ecology's user avatar
  • 143
0 votes
1 answer
5k views

r.series - no output 'ERROR 6: SetColorTable() only supported for Byte or UInt16 bands in TIFF format.!

Using grass tool 'r.series' (average of 2 raster files) with QGIS 2.18.28 works correctly. If I use this tool in QGIS 3.4.4 I get an error message: Processing algorithm… Algorithm 'r.series' ...
Pimpel's user avatar
  • 2,333
0 votes
0 answers
131 views

Slope rasters - different results from different tools

I'm calculating Least Cost Path (LCP) within QGIS 2.18. The first step is to produce the slope raster from the DEM. Using r.slope in GRASS produces excellent results where I can go on and finally ...
IanGS's user avatar
  • 316
0 votes
1 answer
343 views

r.mapcalculator

I am using QGIS 2.18.25. I'm struggling to use r.mapcalc to calculate the ndvi for a workbook project. R.mapcalculator is shown on the workbook I'm using and seems simpler to use. Is there a plug-in ...
Sean Jarrett's user avatar
0 votes
0 answers
720 views

Distance calculation with v.net.path in QGIS 3.2

I have 3 layers: origin and destination point shapefiles and network line shapefiles. I want to calculate the shortest path on the network between the origin (250 features) and destinations (20 ...
Curious Girl's user avatar
3 votes
1 answer
340 views

Deleting floating lines from network using GRASS 7 in QGIS

I'm trying to find a way to remove floating line segments from a road network shapefile. Is there a relatively fast way to identify and delete these features? I've been using GRASS 7 in QGIS to ...
William Olen's user avatar
1 vote
0 answers
40 views

Building graphs between two point layers

I am trying to run a script to find the shortest routes between two sets of point layers (Blue star and Green dots) in QGIS using road network. I am able to use GRASS gis "v.net.distance" ...
user130952's user avatar
0 votes
1 answer
117 views

Error - Grass 7 doesn´t run because isn´t not sucessfully installed

I am having problems to run GRASS7 from the processing tool. Always run the following error that is not corrected instaled. I ve reinstall QGIS several times, even tried different versions,as also ...
Vitor Pina Silva's user avatar
1 vote
0 answers
80 views

Working with GRASS gis in pyQGIS

I am looking for a way to loop through GRASS gis v.net.distance in QGIS. I want to iterate over all the 3 layers which has multiple features at the same time, and print the shortest distance for each ...
user130952's user avatar