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Note that g.region does not change the resolution of your raster layer. What it does is setting the 'working resolution'. Functions will always use that resolution. You can check the current resolution by typing on the command line: g.region -p If raster layers are at a different resolution, they will be re-sampled on the fly. They use, I think, the ...


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You can use r.patch for that (see help file) You probably want to set the region first to encompass all raster layers, after which you can use r.patch to 'mosaic' the layers. The following example is from the helpfile: MAPS=`g.mlist type=rast sep=, pat="map_*"` g.region rast=$MAPS r.patch in=$MAPS out=mosaic


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-1.#IND returns when an incorrect mathematical operation is done, like dividing by zero or the square root of a negative number. Maybe GRASS tool used standard deviation of NoData set as -9999. I suggest two solutions: Check your source NoData value, if it is negative, change it to positive. If you cannot change it or if it's positive, you can convert ...


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As for the second part of your question, v.build.polylines will connect line "segments", removing nodes as long as exactly two line segments are connected. All intersections with 3 or more segments will be left as nodes. I Can't help with the list of nearest neighbors.


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i) seems like nearest point analysis; it is available in ArcGIS, and in GME (search Hawths Tools (Spatial Ecology)), ii) a line clean should sort this out


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Joseph, you're right. Here is the solution to MY problem. May be someone could add some more detail, but this is how I solved it: The region of my interest was about a quarter of the original image so, I clipped the Landsat image to a smaller size, leaving out a big region in which I'm not interested BEFORE start classifying (I was planning to do it at ...


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If you use GRASS GIS from QGIS, you need to understand the commands of GRASS v.surf.bspline uses a Bicubic or bilinear spline interpolation algorithm with Tykhonov regularization. As with all the GRASS GIS commands, It has many options that it is important to understand before applying the algorithm (GRASS GIS is not QGIS): and different results ...


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I faced a very similar problem a while ago: Unable to load 'nviz' through GRASS For me, downloading/installing WinGRASS-6.4.1 and running GRASS 6.4.1.exe seperately from QGIS worked. I was able to use nviz (after configuring the project location and mapsets etc). I still can't run it through QGIS for some reason but seems to work perfectly if I ...


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The Python processing module of QGIS uses the module subprocess to launch directly the GRASS commands with the script GrassUtils.py (in /.../plugins/processing/algs/grass/GrassUtils.py): 1) First it creates a temporary batch file (grass_batch_job.sh or grass_batch_job.bat) in /.../.qgis2/processing/ with the command (def ...


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First of all, you should note that the brovey algorithm implemented in GRASS only works with 3 bands, and you have 4 bands. So, if you want to have four bands you need to to run it twice (once with b1,B2, B3, then once with B2,B3,B4). You then combine the B1,B2,B3 of the first run with the B4 of the second run using r.composite. Concerning the order of the ...


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MSYS stumbles upon the non-ACII characters of your Windows user name. Maybe GRASS fails on that too. Try with a new user name without non-ASCII characters.


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If you look at the Processing Toolbox: There are algoritithms for GRASS GIS 6.x (GRASS commands) and GRASS GIS 7 (GRASS GIS 7 commands). Have you configured the path of GRASS 7 (Configuring external applications) ?


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1) First, you need to consult the r.topidx command of GRASS GIS: With GRASS GIS: The command is r.topidx input=avauffe@tests_divers output=test_topixd 2) same with QGIS The processing log ALGORITHM|Thu Jun 26 2014 ...


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That's a limitation of the shell that you are using (probably CMD on windows, but possibly sh/bash from Cygwin). The GRASS command line is just a normal shell session that has it's path (and other variables) setup properly so you can run the GRASS programs. When you press tab, the shell program tries to complete based on the file and folder names in the ...


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The "ERROR 6: SetColorTable() only supported for Byte or UInt16 bands in TIFF format." comes from GDAL, not from GRASS GIS. It is caused by the limitation of GeoTIFF to handle color tables only for integer but not for floating point data. So, the data are exported properly, just the color table could not be exported as well. Maybe try a different format if ...


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I made a test with OpenJUMP and it also creates more rows (55) with simplification and the reason seems to be that simplification explodes the multipolygons from the original data into simple polygons. Perhaps the same happens with QGIS. If QGIS is doing the D-P simplification with GEOS which is about the same as JTS then this comment from the source code ...


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I asked the original question but I lost my login credentials. Let me give an update. I worked out how to do these non-Euclidean interpolations in ArcGIS but they took a long time to process (many hours). I just recently came across an R package (ipdw) that seems to produce equivalent output 4x faster.


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You have two options, one in pure Python and the second, more classical, parsing the commands of GRASS GIS. 1) in pure Python If I look at GRASS Programmer's Manual: Python (with the version 6.4.3) I still haven't found a way to write data (attributes) to GRASS vectors from Python. But it's possible and easier with the version 7: GRASS 7 Programmer's ...


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As @whuber answered in a Comment, he: used Spatial Analyst's CostDistance to perform non-Euclidean interpolations (and non-Euclidean kernel density calculations). So you definitely can do the work in ArcGIS. Whether you get "equivalent" results in the sense of exactly the same values given the same inputs will depend on minor implementation ...



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