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In spatial hydrology, DEM-based flow accumulation operations are typically static. That is, they represent a steady-state condition of the discharge of surface and near surface water passing through a point. Flow accumulation grids are actually accumulating contributing area downslope, i.e. areas not volumes. The accumulated cells that you described is ...


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You need to understand the principles of GRASS GIS: a LOCATION = one projection (an only one an no "reprojection on the fly" as QGIS, for example) Projections and spatial transformations in GRASS GIS GRASS GIS: Map Reprojection Reprojecting data in GRASS GIS 1) first create an location in the source projection/geodetic datum (using the GRASS ...


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I think that for the input file you don't use the number of band. Your input must be LC81700832014160LGN00_B and then the channel number automatically filled. You can try this.


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As the result is a raster, you need to fix the region before importing the points. Unfortunately, r.in.xyz does not allow you to do that directly (as other commands). Whith your 10 points in the GRASS shell (or in the Command console): r.in.xyz input=test.xyz output=testxyz x=1 y=2 z=3 fs=' ' Reading data ... 100% Writing to map ... 100% r.in.xyz ...


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It's no so elegant, but renaming LE70010752014040CUB00_B6_VCID_1 to LE70010752014040CUB00_B61 do the trick. If there's a way i can do this with patterns it'll be better.


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Like mentioned before, you might want to try OSSIM. It is a series of commandline programs and one or two GUI's. I am currently trying that out. There is no option to use a cutline as far as I know. Information about OSSIM: http://trac.osgeo.org/ossim Installers can be found at: http://download.osgeo.org/ossim/installers The current GUI is called ...


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I had a similar problem. PostGIS wanted libgdal1 and QGIS wanted libgdal1h. The problem was that I had my Repo for QGIS set to the main QGIS site, and Postgresql set to their main site. Postgresql kept wanting to upgrade past what QGIS wanted. Finally something gave and I ended up with circular conflicts between the two. I ended up backing up my ...


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Here is an approach in R. It is computationally expensive and very slow when applied to large rasters. Because of this, I added a point sub-sampling approach that seems tractable. I should note that, because the raster needs to be coerced into a vector, this function is not memory safe. This function returns the percent volume data and not a contour, but ...


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It is possible to iterate over points/vertices by directly accessing the vector geometry through pygrass. # Get and plot the coordinates of all of the points in a vector file. # Then generalize this to lines (this will probably work for boundaries # too). # I'm answering it for both here because (1) this is the way I worked # through the problem, and (2) ...


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You can try to set the language in both QGIS and GRASS. For QGIS: Settings > Options > Locale > place checkmark beside Override system local. For GRASS: Launch the GRASS GUI > Settings > Preferences > Appearance > Language Settings.


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A NaN is different than NA. The NaN often results from a divide by zero error whereas NA is the R value for no data. These values behave in specific ways and it would be good for you to read some R background material to understand the behavior. Two useful operators to be aware of are: is.na() and is.nan(). y=c(0,1,2,3,4,NA) x=c(0,1,2,3,4,NA) (d=x/y) ...


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I will provide here commands but you can just find the given options in the dialogs. According to your question I suppose you already have a GRASS imagery group. So, I will just focus on exporting the group into a multi-band image format. First see what are the output formats are supported: r.out.gdal -l This will give you long list which contains also ...


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QGIS can handle lyr files, see Does QGIS have the equivalent of ArcGIS's Layer (*.LYR) file? Note that lyr is not just geometry and attributes as a shapefile has, but also styling. You can not save that part in the shapefile format. The feature has found its way into QGIS stable by now. Since QGIS is a lot more user-friendly than GRASS, I suggest to ...


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The regionsize is about 5x5 km. Your Idea is also a verry good one but for my Bachelorthesis i have to do it as i told. Maybe my method is better understood when I point my entire Process here: I also tried v.segment and v.to.points. But i canĀ“t choose a equidistant Distance between Points with that. So is there no other way?


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There are two GRASS modules for creating a set of points from a line vector: v.to.points or v.segment. The first will extract all the existing nodes from the line, and will stick in extra points if two nodes are more distant than dmax parameter. The second allows more accurate control over the exact locations of the points. See the manual pages for better ...


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GRASS GIS is not QGIS and it has its own user interface. 1) unable to fetch interface description for command 'r.stream.order': if you want to use an add-on, you need to install GRASS GIS and not the version installed with QGIS which is designed to work with a QGIS interface (grass plugin and processing). The error means that the plugin cannot build his ...


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Looks to me like you have the x and y mixed up. Your region's north is 485999 but the maximum y in the input file is 6508999. Try setting the region as: g.region -p n=6509000 s=6508000 e=486000 w=485000 res=2 Then do your r.in.xyz command.



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