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I solved the problem in this way .... First, I removed all QGIS packages and its dependencies, but not Grass 6.4.3. !! I also changed debian repository (in /etc/apt/sources.list) from 'deb http://qgis.org/debian trusty main' to 'deb http://qgis.org/debian-ltr trusty main' (so I can install QGIS 2.8 LTR). Then I followed these steps : sudo rm -rf ...


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There seems to be some trouble with GRASS 6/7 support as a plugin and in processing: http://lists.osgeo.org/pipermail/qgis-developer/2015-July/038601.html http://lists.osgeo.org/pipermail/qgis-user/2015-August/033174.html I guess you have to downgrade and follow the mailing lists for any progress.


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There seems to be some trouble with GRASS 6/7 support as a plugin and in processing: http://lists.osgeo.org/pipermail/qgis-developer/2015-July/038601.html http://lists.osgeo.org/pipermail/qgis-user/2015-August/033174.html I guess you have to downgrade and follow the mailing lists for any progress.


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Try r.out.gdal. First, at the layer properties, you can see the raster data type of the original raster. Afterward, at the Modules List of next image, you have the parameters used by me for exporting the raster as *.tif. At the next image you can see that the process was successfully finished. The resulting raster (it was as I expected; without the ...


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The problem has a few days ago been solved in QGIS master. I have prepared a patch for QGIS 2.10 but I hope that the QGIS developers will backport it. Since only Python changes are involved, an existing installation can now be easily fixed without having to reinstall everything.


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The question is essentially a dupe of http://gis.stackexchange.com/a/150497/687 In short: the upgrade development to GRASS GIS 7 is work in progress and will be shipped (to my knowledge) with QGIS 2.12.


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I imported my raster file to PostGIS and I used this function to make vectorization of my raster. I used this query SELECT (ST_DumpAsPolygons(rast)).geom,(ST_DumpAsPolygons(rast)).val from my_raster


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In case anyone else is looking for a resolution for this problem, gdalwarp fixed it for me. I used the following command in QGIS and then I was able to import the image into GRASS. gdalwarp -t_srs epsg:<epsg-number-of-your-southern-utm-zone> <input-band> <output-file>


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To install the lastest stable QGIS and GRASS 6 I use: sudo apt-get install python-software-properties sudo add-apt-repository 'deb http://qgis.org/debian trusty main' gpg --keyserver keyserver.ubuntu.com --recv DD45F6C3 gpg --export --armor DD45F6C3 | sudo apt-key add - sudo apt-get update sudo apt-get install qgis python-qgis qgis-plugin-grass grass-gui ...


1

According to the docs thinning is for line features. Remember to select "area" as the feature type in r.to.vect.


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After some more Googling, I came across a solution to a different problem that has also solved this problem. The simple fix was to locate the GRASS database and mapset in a different folder which did not contain any spaces in the name. Hope this helps anyone else facing the same issue.


1

I don't know any way of doing this without writing custom code.. this is a use case I've come across in the past, but there doesn't seem to be an easy way to do it. I'd be delighted if someone points out an easier/quicker solution! There are several good stats based plugins, but they're for vector layers. Zonal Statistics is good for finding summary stats ...


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It seems that you final goal is to total raster values for each vector polygon. It's worth pointing out that the GRASS module v.rast.stats does just that.


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I think gdal_polygonize might help you. It will convert a raster to vector format (GML, shapefile, etc). By default it connects the cell that have same values, but from your description, it should not be a problem. This text comes from the official site: This utility creates vector polygons for all connected regions of pixels in the raster sharing a ...


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They're a common alternative to hdf files in remote sensing and climate research because they're good for storing multidimensional data and time series information. You have to be careful about what version of NetCDF you're working with though. Newer NetCDF formats can be based off of hdf5 and these need to be opened using the Rhdf5 package in R and should ...


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GRASS GIS provides the v.net.iso module which is equivalent to the trade area in ArcGIS. See the documentation and examples based on distance and travel time: http://grass.osgeo.org/grass70/manuals/v.net.iso.html


1

I faced the same problem just recently. And I've found a way of getting a better path. In my case, I was trying to visualise the effect of having the Panama and Suez canals. My suggestion isn't going to help you find the exact distance, however - but it will trace a more realistic minimum cost path which should be closer in length to the real optimum. ...


0

How I solved my little problem: 1. Firstly, vectors of required 'cost areas' were created (was trying to do it in GRASS but it's too painful - ended up in QGIS). 2. Then I set appropriate cost values for each of such 'cost area' vectors (by this point I was already working in GRASS; we set cost values by adding new column in the attribute table of each ...


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Open "QGIS Browser 2.10.1 with GRASS 6.4.4". Find the vector or raster layer in the "header window". Click on the layer and drag it over to your QGIS "Layers Box".


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Check this page for the development progress: http://www.gissula.eu/qgis-grass-plugin-crowdfunding/progress.html I assume you use QGIS 2.10 with GRASS 7. The site above states that mapset management will be implemented for QGIS 2.12, whereas in QGIS 2.10 GRASS plugin browser and add layer tools removed, substituted by standard QGIS browser. I.e. at ...


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I had the same issue. It was related to the flags in cmake. My purpose was not related to GRASS 7 so I just had to desactivate it. My line for compiling is similar to below (I didn't provide all the options just the ones related to GRASS) cmake -DWITH_GRASS=OFF -DWITH_GRASS7=OFF .. You need to do before a make clean You can also check if your ...


2

As stated in your comment, the upgrade to GRASS GIS 7 helped - a lot has been invested to simplify the usage (more to come!). Be sure to consider for raster data the computational region, however, this is easily done via right mouse button in the map layer manager. Note that you can create a GRASS GIS location directly from the data set: ...


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You will need to compile the source code since this part is written in C programming language. I would be willing to backport the improvements from GRASS GIS 7 to 6 if you open an enhancement ticket at http://trac.osgeo.org/grass/ requesting this backport.


0

You can identify the number of the catchment you want to work on with the query tool in the graphical user interface or r.what and then use r.mask to restrict the computation to only this catchment. Subsequent computations with then only consider this part of the data. With r.mask -r you can eventually remove the MASK later.


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Let me suggest to use the nice vector network analysis tool which you can find in the menu (manual page). It allows you to snap the points to the network (second icon under "Points for analysis") automatically and is really easy to use. Two screenshots generated based on your data (I created a LatLong location, epsg:4326 for it). Travelling salesman in ...


0

I know this is an old question, but here's a crack at the answer. My approach seems a little convoluted to me, but it's the best I could think of. I used GRASS 6.4. g.region s=0 w=0 e=100 n=100 res=1 # set up some polygons echo "B 4 10 10 10 20 20 10 10 10" | v.in.ascii -n input=- output=polygonA format=standard echo "B 4 90 90 90 80 80 90 90 90" | ...


0

Found a solution using ArcGIS: I use the tool 3D Analyst >> Data Management >> TIN >> 'create TIN' to create a TIN file with the setting 'SF Type: hardclip'. Then I use the tool 3D Analyst >> Conversion >> From TIN >> 'TIN to Raster' to create the raster DEM. Because of the size of the buildings that I want to identify (singe residential ...


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I may have found a solution to my own question, but I am not sure: v.kernel -v input=MY_LOCATIONS net=MY_NETWORK output=MY_OUTPUT stddeviation=57.735 distmax=1 mult=200 kernel=uniform The parameters and values in bold are important. Where do they come from? The kernel surrounding each dot has the uniform distribution with a range of 100 m at both sides of ...


1

Yes and you can automate this process with python grass.script or bash script (bat script in Windows). I test it in my system and the individual commands are (for my line vector named route and raster dem named utah_demUTM2): v.to.rast input=route value=1 output=route_raster r.thin input=route_raster output=route_raster_thin r.mapcalc ...


0

If the least cost paths were extracted from a raster map, then I assume they would have line vertexes that fall on the raster cells (unless you used the knight's step but it may still work well enough). You could then: run v.patch on all your vector LCPs (I think this would be pretty fast even on a large number of vector maps) run v.to.points, which will ...


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Not a real solution ... but you may use r.carve first to burn the main flowline into the DEM. Then re-run r.flow on that. In order to find the main flowline, some v.net.* modules may help (shortest path perhaps). In essence, using a dual-step approach.


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Please consider to ask the authors and invite them to enhance the manual page. They will know best how to deal with the preparation of the input data.


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Have you enabled the advance interface :


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Under Windows you have a "special version" of QGIS with GRASS available: Start this special version and enable the now available grass-plugin: Go to Menu Bar / View / Panels and check, that its enabled (should be already by default) Go to Menu Bar / View / Toolbars and check, that its enabled (should be already by default)


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In 2.10.1 I'm able to access GRASS Tools panel, and GRASS toolbar by: Enabling GRASS plugin Go to Menu Bar / View / Panels and confirm GRASS Tools is checked Go to Menu Bar / View / Toolbars and confirm GRASS is checked Then, I'm able to click the 'New Mapset' button in the GRASS Toolbar.



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