Questions tagged [qgis-grass-plugin]
QGIS pluging which provides to access GRASS GIS databases and functionalities
91
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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 ...
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1
answer
79
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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
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38
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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 ...
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1
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0
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134
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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 ...
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193
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Strahler stream order is not generated in any of the algorithm SAGA, PCRaster or GRASS in QGIS
When generating strahler order by SAGA in QGIS it indicate that
QGIS version: 3.22.6-Białowieża
QGIS code revision: b6f33b1a
Qt version: 5.15.2
Python version: 3.9.5
GDAL version: 3.4.2
GEOS version: ...
8
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1
answer
1k
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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 ...
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35
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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 ...
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2
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0
answers
263
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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 ...
0
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1
answer
309
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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 ...
- 11
1
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1
answer
653
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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:
...
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1
answer
182
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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 ...
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3
votes
1
answer
56
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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 ...
- 133
2
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0
answers
346
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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.
...
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0
answers
937
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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://...
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3
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2
answers
3k
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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 ...
- 613
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2
answers
242
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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 ...
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2
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1
answer
205
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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....
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-1
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1
answer
62
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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 ...
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1
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217
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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'
...
2
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0
answers
40
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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 ...
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4
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1
answer
284
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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 ...
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1
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2
answers
94
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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 ...
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1
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0
answers
158
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. ...
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1
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1
answer
263
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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 ...
- 59
0
votes
2
answers
400
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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 ...
- 3,460
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1k
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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 ...
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1
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0
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219
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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 ...
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0
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20
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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 ...
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3
votes
2
answers
541
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 ...
4
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2
answers
1k
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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 ...
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0
answers
80
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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 ...
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162
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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 ...
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1
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1
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4k
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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' ...
- 2,315
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0
answers
112
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 ...
- 164
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1
answer
294
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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 ...
- 361
0
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0
answers
654
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 ...
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3
votes
1
answer
298
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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 ...
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1
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0
answers
36
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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" ...
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1
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105
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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 ...
- 207
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0
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75
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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 ...
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5
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2
answers
8k
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GRASS GIS Plugin not loading in QGIS 3
When starting up QGIS 3.2.2 (also tested with 3.2.3), I get the following message in the "Plugins" Log Message Window:
2018-10-18T08:03:48 WARNING Failed to load C:/OSGEO4~1/apps/qgis/plugins/...
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0
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325
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r.series GRASS algorithm in QGIS 3.2 output no-data image
I'm trying without success to calculate a standard deviation image from 4 input images. I already used the r.serie algorithm in 2.18 to calculate an averaged image. Know after upgrading to 3.2.2 on ...
- 181
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1
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160
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Adding GRASS module to QGIS 2.18.21
I did a module in grass wich I called r.out.haralickFeatures.py. I did a .qgm. I can't get the parameters rigth.
#!/usr/bin/env python
#%module
#% description: Compute asm, contrast, var, idm and ...
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1
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1
answer
241
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Grass averaging raster not working with: Could not read georeferenced file error
I am trying to average geotiff using grass files using r.external and r.series. The geotiffs are georeferenced with wgs84. The command is below.
grass74 g.proj -c proj4="+proj=longlat +datum=WGS84 +...
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2
votes
1
answer
506
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Find distance between point layer and lines layer in QGIS?
All the answers were for one point and one line, But I'm talking about one point and multiple lines, and for older versions of QGIS.
I have two shapefiles including one point layer and multiple lines ...
2
votes
0
answers
95
views
No attribute table or values in QGIS 3.2 Grass toolbox plugin output files
Using the Grass toolbox within QGIS 3.2 (and previously 3.0) when I import any files and overlay them, then use the "View Output" option (button), the resulting file has the correct polygon areas ...
- 907
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vote
1
answer
784
views
GRASS 7.4.1 in QGIS 2.18
I am a new user to QGIS and GRASS.
I want to use v.centerline so I opened GRASS as administrator on Windows 10 and I went to the gui of g.extension and successfully installed v.centerline.
I opened ...
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2
votes
0
answers
108
views
Can't get GRASS 7 V.kernel.vector to work on QGIS 2.18.14
I have reinstalled GRASS multiple times, with all of the necessary listed programmes to install beforehand (e.g. GDAL), and it won't work.
The error comes up - GRASS was not found in '/Users/Shared/...
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6
votes
1
answer
2k
views
Getting log error about default locale settings when using GRASS with QGIS?
I downloaded python 3.6, installed it, dowloaded QGIS 3.0.2, installed GDAL, then QGIS, then opened QGIS and tried to use GRASS processing tools. Initially I got the following error:
env: python3: No ...
10
votes
2
answers
2k
views
QGIS GRASS Processing Not Working on MacOS?
Recently upgraded to QGIS3 (3.0.2) for MacOS (High Sierra) and encountered GRASS (7.2.2) issues. Tried adding a custom variable and now when running GRASS algorithms (e.g. r.reclass) I get the ...
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