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1

The raster= parameter of g.region needs to be a GRASS raster, not a tif file. You need to first import the tif into GRASS with r.in.gdal. You can import the tif, and set the region to match the new raster in one go with the -e option to r.in.gdal like: r.in.gdal -e ...


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Figured it out - the problem was that my original geotiff was not properly projected. I fixed the projection and the raster calculation works.


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The main reason for the halt of the processing of big polygons is the big number of vertexes. It is better to smooth big number of small totpolygical correct features then just one big. Try to split your polygons in a few smaller ones and then use v.generalize. This preserves the topology and you can merge the polygons after that in one big polygon using ...


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One suggestion would be to ensure that the computational region is correctly set, i.e.: g.region rast=tile1,tile2,tile3,...,tilen -p Then you should run the r.patch command: r.patch input=tile1,tile2,tile3,...,tilen output=merged_raster You should be able to display the merged raster in your GRASS monitor. If it is still blank, try passing -z to ...


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What you need to do is add a single category value to all polygons in a second layer, then run v.dissolve using that layer 2. This will remove all common boundaries. Here are the steps (say your original is named "polys"): v.category polys opt=add layer=2 out=polys2 cat=1 step=0 v.dissolve input=polys2 layer=2 out=polys3 v.db.addtable polys3 ...


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There is a workflow to fill in NA values by the nearest non-NA value in R here. You can easily set a maximum distance (in map units/meters).


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Here are some ideas that should get you closer to a solution. First, given a reference point with location (x,y), then the points on the circle of radius 1000 m, at angles theta1 and theta2 will have coordinates: x1 = x + 1000*sin(theta1) y1 = y + 1000*cos(theta1) x2 = x + 1000*sin(theta2) y2 = y + 1000*cos(theta2) With the three points (x,y) (x1,y1) and ...


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You probably need to add something like raster = processing.getObject(RASTERLAYER_BAND) and remove nodatabackground=processing.runalg(...) The following works for me: ##NoData Background=name ##RASTERLAYER_BAND=raster ##nodatabackground=output raster import processing raster = processing.getObject(RASTERLAYER_BAND) ext = raster.extent() a = ...


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The error report tell you that that you have entered illegal parameters. The values cant be over +/-180 for X and +/-90 for Y In the tool box, try setting the xmin and ymax to -180 and 90 respectively. Since the GRASS tool takes these attributes from the layers, it might hint that there might be an underlying error with the source layer's CRS or ...


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GRASS GIS is using GDAL as backend for reading and writing raster and vector data. If your GDAL installation supports JP2 then also GRASS GIS will import these data. Please post more information about the GRASS GIS and GDAL version you use.


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Just to add to @ShahzadBacha's great answer, you can also use: SimpliPy (Plugins > Manage and Install Plugins...) PolygonSimplifier (Plugins > Manage and Install Plugins...) v.generalize (Processing Toolbox > GRASS Commands > Vector (v.*) > v.generalize) And if you're feeling brave, you can: Convert your polygons to lines (Vector > ...


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You can use simplify geometries in QGIS vector > Geometry Tools > Simplify Geometries the higher the tolerance value the greater the simplification


2

Version 7.0.2 is an older one. The current release is 7.0.4: https://grass.osgeo.org/news/56/15/GRASS-GIS-7-0-4-released/ If you are speaking about MS Windows, the older addons are still online but you would need to copy the files manually: https://wingrass.fsv.cvut.cz/grass70/x86/addons/ Installation trough g.extension is no longer supported for ...


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What is your OS, Windows, Linux, Mac OS X ? It is important because the addon needs to be compiled From g.extension On MS Windows systems, where compilation tools not readily available, g.extension downloads a compiled executable from the GRASS GIS project server. On all other operating systems where it is not difficult to install compilation tools, ...


2

Not sure how you are accessing GRASS, but the documentation reads to me like this is an Addon. I just went to the command line typed "g.extension" and a window popped up that I linked to the source page (https://svn.osgeo.org/grass/grass-addons/grass7/raster/) and put in the addon name (r.stream.order)... and it did its thing... hopefully that does it for ...


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Another way to work with the images using the GUI is: First in a new project add the .hdf as a raster and select which band do you want to work with. QGIS will set a new user defined CRS with a number, for example in my case USER:100008. Go to Raster>Projections>Warp(Reproject). You will reproject each one of the bands given an different output name for ...


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In GRASS GIS 7, there is r.skyview addon for sky-view factor, which is very similar to openness. You can check the implementation details here. Download the addon with g.extension r.skyview.


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You might look at two things: First check your region settings before running r.patch. You need to make sure that the computational regions covers all the original rasters, and it at the same resolution as the originals. The typical ways to do this is: g.region -p rast="<list of all your two original maps, separated by comma>" Next, after doing the ...


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QGIS has ability to connect to GRASS.Follow the below links to integrate GRASS plugin with QGIS.Add GRASS vector data to QGIS and export into shapefile or any other format. https://docs.qgis.org/2.6/en/docs/user_manual/grass_integration/grass_integration.html http://qgis.spatialthoughts.com/2012/01/setting-up-working-grass-environment-in.html


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You may export to Shapefile with v.out.ogr Example from the doc: v.out.ogr input=lines type=line output=lines.shp



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