Tag Info

New answers tagged

0

Thanks for the report. I hope that I got it fixed in r62901. Please try again to install the addon as before so that the latest version gets fetched from the Addons repository.


3

The r.li suite has been completely rewritten. While in the past it ran in parallel mode, the results were not reliable. The only way was to rewrite it from scratch at the expense of the multi-core approach. Please try a recent (i.e. less than 1 week) SVN snapshot of GRASS GIS 7 to use the now working version of r.li.


1

Nine points is a quite small number, so I would use some arbitrary boundary instead of trying to build a complex algorithm that might "go wild". I suggest that you use r.grow.distance in grass to create a distance layer around your points, and to set a threshold that would constraint the size of your study area (for instance, the largest distance value ...


0

Please consider to use v.net.path - finds shortest path on vector network or v.net.alloc - allocates subnets for nearest centers. See also the list of available vector network algorithms. The v.distance command will find the shortest direct distance but you likely want to follow the network in order to obtain more realistic distances.


1

There is something wrong with the Shell where it does not load the Grass /bin into $PATH My solution is to do it manually inside the Shell. $ echo $PATH /usr/bin:/bin:/usr/sbin:/sbin $ PATH="/Applications/QGIS.app/Contents/MacOS/grass/bin:$PATH" $ export PATH $ echo $PATH /Applications/QGIS.app/Contents/MacOS/grass/bin:/usr/bin:/bin:/usr/sbin:/sbin ...


1

1) Does r.neighbors walk through the raster collecting cell values? The neighborhood operators determine a new value for each cell as a function of the values in its neighboring cells. All cells in a raster map, except for the cells at the map boundaries, become the center cell of a neighborhood as the neighborhood window moves from cell to cell ...


1

in GRASS you can do that (extract rivers) from a DEM (which gives you informations only regarding "height" of the single pixel - there are not rivers "included" in this kind of information). You can use GRASS by Qgis too (there is a useful GRASS plugin) and the tool to extract rivers is called "r.watershed". As rightly @underdark said, you need to decide ...


1

If you want to create a map, forget GRASS and use QGIS instead. Load both the rivers and the elevation data. Double-click on the layer names and go to the Style section to change the colors and you are all set.


1

In Mac OS X, with the Kyng Chaos version, the directory where grass64 is located is the application itself. If you want to launch GRASS-6.4.app from the command line (Terminal), the path that the app uses is: /Applications/GRASS-6.4.app/Contents/MacOS/grass.sh If you want to add something to your .bash_profile, use an alias alias ...


1

In general, to create a map of sinkholes using a DEM, you would first fill the topographic depressions (sinkholes) then difference the original DEM from the filled DEM. This gives you 'depth in sink' but if you simply want a Boolean sink map, reclass the depth map such that 1 is assigned to all values greater than 0. The tool in GRASS GIS to fill depressions ...


1

You can certainly start GRASS without the gui: grass64 -text Furthermore, you can run GRASS in batch mode without actually "starting" the program at all. If you prepare a bash script which sets up the required environment, then you can have GRASS commands run without the GRASS interface at all. Full details in the grass wiki


0

Have you seen this command? g.mapset


4

GRASS GIS has: r.fuzzy: Cluster raster maps using fuzzy logic. In addition GRASS GIS 7.x has r.fuzzy.system Full fuzzy logic standalone classification system with few fuzzy logic families implication and defuzzification and methods Look at Application of GRASS fuzzy modeling system: estimation of prone risk in Arno River Area (pdf), for example. I ...


4

There is a difference in wording but I think the options from the Generalizer plugin exists in the v.generalizer interface. Using Google Translate (yes, not the best thing to use) for the Generalizer Homepage, we can find a description on each algorithms used and their corresponding parameters. In terms of Hermite Spline Interpolation, the homepage tells ...


0

Just for the record: we have collected a series of related questions and answers at http://grasswiki.osgeo.org/wiki/WinGRASS_errors Hope the page addresses 99% of the issues you may encounter :-)


4

It seems that you must use the Dissolve tool, based on a common attribute. http://resources.arcgis.com/en/help/main/10.1/index.html#//00170000005n000000


0

With GRASS, you can use a combination of r.mapcalc and r.out.xyz. First, you use r.mapcalc to select only those cells with the desired value: something like intermediate_map=if(source_map==value) should create a map that contains only the cells with the desired value. Second, you export this intermediate map using r.out.xyz input=intermediate_map to create ...


2

Okay, here's a way to do it using Numpy and Rasterio. I'll show you an excerpt from Rasterio's rio-insp prompt using a test raster (rio insp tests/data/RGB.byte.tif). >>> r, g, b = src.read() >>> rc = np.transpose(np.nonzero(r==42)) >>> xy = [src.ul(row, col) for row, col in rc] >>> print xy[0:5] [(308411.0935524652, ...


1

You can use args and kwargs technique as suggested by Nathan W but I would avoid that unless you need it also for something else. The preferred syntax is appending and underscore (class becomes class_): from grass.script import run_command ... run_command('i.maxlik', ..., class_='classification', ...) This applies to all functions form start_command ...


0

In case somebody would be interested I did the test in GRASS GIS NC sample location using the raster map elevation (DTM) and GRASS GIS 7. Look at elevation raster map using r.info elevation which gives ... | Rows: 1350 | | Columns: 1500 ...


2

Only a small modification is needed: You need to generate the group prior to exporting (i.e., use i.group), then export to a multilayer file by assigning the group name as input in the r.out.gdal call.


4

Given your error, my guess is that when you are importing the file to GRASS, it is expecting a GRASS ASCII raster format, which has a header that looks like this: north: ####.### south: ####.### east: ####.### west: ####.### rows: ####.### cols: ####.### Instead of an ArcGIS ASCII grid, which has a header that looks like ...


1

The columns parameter should have the resulting column names and types in the same order as they are on the input file. So for your file it should be something like: col='p varchar(8), x int, y int, band int' The single or double quotes should not be an issue Please note that you don't have to specify the cat parameter if the input file itself doesn't ...


4

First, you could try to find out whether the map was imported or not: use the g.list tool for that (GUI: File -> Manage maps and volumes -> List). Sometimes the GRASS modules add an imported map to the layer tree even though the import was unsuccesful and consequently the map is not there, resulting in the error message you refer to. Second, if the map was ...


1

r.in.gdal is a command to import rasters into GRASS GIS, not into QGIS There are two options to use GRASS GIS in QGIS: 1) with the grass plugin you are working in GRASS GIS and you can use r.in.gdal in the Python console of GRASS GIS to import a raster into a Location/Mapset. 2) from processing you are working in QGIS with a "virtual" ...



Top 50 recent answers are included