GRASS GIS (Geographic Resources Analysis Support System) is a free, open source geographical information system (GIS) capable of handling raster, topological vector, image processing, and graphic data.

learn more… | top users | synonyms

0
votes
1answer
65 views

Problem installing r.hydrodem with g.extension in GRASS 7.0.0svn (r61585M) on mac OSX 10.10.1

I'm very interested in using the function r.hydrodem in GRASS, unfortunately, I'm running into some problems when trying to install this add-on in GRASS 7. I've tried installing some other add-ons ...
0
votes
0answers
37 views

6s parameters used in grass gis

I am working on grass gis 6.4.4 , i.atcorr module. There is no clear document for the parameters used for the calculation of 6s output parameters. I want to know about the parameters such as ti.sast, ...
0
votes
0answers
37 views

computing the volume of a cave

I did a cave survey and now I have a dxf file 3d. It's composed by 8 layers: polygonal points width contour width height contour height stations depth I would like to make a volume and change its ...
0
votes
0answers
19 views

bug in i.rgb.his

I found that the implementation of i.rgb.ihs in porcessing toolbox needs to be corrected. It is necessary to have admin permissions to correct the file i.rgb.his.txt locate in ...
0
votes
0answers
27 views

how to compile i.atcorr separately without compiling whole grass

i am working on grass. i need only i.atcorr module. should i compile whole grass 6.4.3 or any option is there for separate module compilation. I tried to compile entire gras6.4.3 on windows system but ...
0
votes
0answers
77 views

Importing raster and vector: GRASS GIS 6.4.4

Almost giving up on this task, and need some support. I´ve been studying GRASS GIS and training with some tutorials with The NC-dataset. What I want is doing the same task as the one called "Surface ...
0
votes
0answers
24 views

GRASS GIS 6.5SVN : r.watershed failed to display basin and accumulation maps

I am passing DEM and threshold values as inputs.I want to get basin and accumulation as outputs.I tried it in Grass,process was completed.while dispalying result it is showing white screen (both ...
0
votes
0answers
37 views

How can I implement GRASS GIS flow direction process from DOS scripting

When I try to implement its showing it work completely in its command prompt(grass) and creating output files also but when I try to view the result its not showing anything in Map Display I ...
0
votes
1answer
91 views

trying to calculate volume using r.volume GRASS - error message

I am trying to calculate volume using GRASS plugin in Qgis using module r.volume however the attached error message keeps appearing. Any ideas?
0
votes
0answers
25 views

PostGIS commands in GRASS

How does the geometry get referenced in GRASS when using a PostGIS command like st_within? e.g: echo "UPDATE file SET within=(select file2.name from file, file2 where st_within(file.geom,file2.geom) ...
0
votes
0answers
68 views

How to reference a number variable in r.mapcalc within QGIS graphical modeler

I need to run the following formula in r.mapcalc: (xor(abs(A-B),abs(A-C))>120)*A I would like to however use a user defined number input variable instead of the 120. I already have this variable ...
0
votes
0answers
59 views

r.walk: Incorrect cost parameter values on GRASS GIS Windows version 6.4.3

GRASS GIS 6.4.3 (MS Windows OS): When I run r.walk (from command line), the cost parameters (a,b,c,d) come back like this: Walking costs are a=0.000000 b=-0.000000 ...
0
votes
0answers
59 views

QGIS DEM Output cell size does not match DEM input cell size

As my first post I offer a humble apology if this is such a basic question as to make any of you cringe. I feel like I have exhausted my search skills and read through the QGIS documentation ...
0
votes
2answers
180 views

QGIS – Raster Calculator: Using flat (no data) areas of an aspect-raster in the raster calculator

I´m playing around with the Raster tools, following more or less the qgis-tutorial but using my own data. When I calculate the aspect of a DEM, flat areas are (logically) left without data. However, ...
0
votes
1answer
192 views

What is the typical v.surf.xxx exicution time?

What is the typical v.surf.xxx exicution time? I am trying to run v.surf.bspline on a set of ~1600 points. It has bee running for about an hour now and is stuck at spot indicated in the image. I ...
0
votes
1answer
87 views

r.composite gives blank image output in GRASS GIS

While running r.composite in GRASSGIS GUI command the image formed looks absolutely blank. The data I used is listed here below. IRS-LISS III Multispectral coverages. (i.e. band 2, 3 and 4 for Blue, ...
0
votes
1answer
114 views

Help me to understand how i.fusion.brovey works in Grass 6.4.3

I'm using Grass 6.4.3 in Linuxmint 16. I don't have a very big problem but I'm trying to understand what is Grass doing, if I'm applying the process correctly and if there is something wrong with my ...
0
votes
0answers
37 views

qgis: module crashed or killed

using Grass 6.4.3. via Qgis 2.2.0 Valmiera (standard installation package): Why would Grass modules suddenly produce a "module cashed or killed" error. specifically in relation to r.surf.idw2 and ...
0
votes
1answer
85 views

GRASS GIS v.in.ply

I'm trying to import a .ply file from MeshLab 1.33 into GRASS GIS 7.0 using v.in.ply addon, but I get the error message: ERROR: List index must be integer, is uchar This appears to be referring to ...
0
votes
0answers
123 views

Running a batch script in GRASS command line - v.dissolve and v.db problems

I have been writing a number of scripts for automating isochrone production in GRASS just using the command line. I create files with isochrone lines in them and then a buffer around each of the ...
0
votes
1answer
38 views

r.series command in QGIS - timeseries

I am using r.series command in qgis. The command is performing correctly, but when I import input raster files, it creates a list in a random order. Sometimes the order of input rasters is essential ...
0
votes
0answers
50 views

Time processing in GRASS?

I am computing NDVI for Landsat TM in grass 6.4.3 in raster map calculator, and time processing is many hours and finally tke message is "failed". trying to find a solution I discovered that it ...
0
votes
0answers
32 views

Changing tracks to vectors in a grid

This is a version of a question that I posted on the GRASS list, but I didn't get any suggestions there. I would like to overlay a grid (cell size about 500 m x 500m) over an animal track created from ...
0
votes
0answers
36 views

R equivalent of GRASS r.grow?

What is a good R equivalent of the GRASS function r.grow? The closest I've been able to find is the script suggested by whuber in response to Creating randomly shaped clumps of cells in a raster from ...
0
votes
0answers
75 views

v.buffer angular buffer doesn't take all the polygons into account

I am trying to create an angular buffer around building footprints with the v.buffer command (QGIS 2.2). There is no error message, but the algorithm doesn't take into account all the buildings. This ...
0
votes
0answers
25 views

Is it possible to compile a grass addon into a commandline app?

As the title says, I'm wondering if it's possible to take the source of a grass add-on and compile it into a commandline app. Or, alternatively, use the add-on in a python program. Basically, I ...
0
votes
0answers
88 views

How to make DTM Qgis-grass

Good evening, I need help. Should I create a dtm of an area in the province of Vicenza. It 's the first time I try, I tried the tutorials on the Internet but I could not understand how to do it. Could ...
0
votes
2answers
75 views

GRASS GIS using a loop with r.neighbors command

I'd like to do a trend analysis with ndvi data from 1982 til 2005. I am using the r.neighbors command to get first the spatial variance (then I would use r.series method=slope to get the actual trend) ...
0
votes
1answer
119 views

grass - add on problem

I can't install the addon in grass 6.4.3 to my linux mint. i've already installed the SVN and than it says: GRASS 6.4.3 (fabian_idrisi):~ > g.extension r.fuzzy Fetching from GRASS-Addons SVN (be ...
0
votes
1answer
23 views

Problems installing r.roughness

I am trying to install r.roughness in GRASS 6.4.3. It starts compiling but at the end I get this error: ERROR: Module did not install properly I cannot identify the problem. Can somebody that has ...
0
votes
2answers
66 views

How to remove small areas without reducing borders

I'm having a problem where I am overlaying two maps to create a new kind of map with the data conjoined. In general this is good, but I need to remove the smaller areas from it. For the interior ...
0
votes
1answer
66 views

Producing gradients between shapefiles and using original boundarys as isoclines (lines)

to produce a bathmertical map of a river bed I draw shapefiles showing the different depths based on satellite images taken during different tidal levels (deepest, 2nd deepest, 3rd deepest, shore ...
0
votes
1answer
25 views

vector file is used by two mapsets at a time in grass gis

i want to study about vector processing.if a vector file is used by two mapsets at a time, which one will be saved first and why.if a team want to work on the same set of shape files, what is the ...
0
votes
0answers
168 views

No data appears when using gdal_calc.py but source had data values

I'm in the process of calculating topographic exposure using a mix of GDAL, grass, R and python in Windows. I need to process a very large tiff file using the following calculation: ...
0
votes
1answer
70 views

RuntimeError from r.viewshed in graphic modeler

after using r.los in QGIS want to switch to r.viewshed in GRASS GIS 7. i need to do a lot of viewshed analysis form given points of a vectorlayer. if i try to add r.viewshed to the graphic modeler i ...
0
votes
1answer
81 views

QGIS-Processing GRASS-tools don't work

When I try to use the processing grass tools like r.series I always get the following messege. I deinstalled QGis and reinstalled the program totally fresh without success.
0
votes
0answers
106 views

Grass 7 voronoi vertices error

I tried the voronoi diagram for area function and got the message "ERROR: Found 0 vertices" - any suggestion ?
0
votes
0answers
81 views

r.shaded.relief plugin on a DEM layer

I loaded a raster digital elevation map from the DEM explorer website. I defined the projection and created a mapset. I then loaded the raster file into GRASS with the r.in.gdal plugin to create a DEM ...
0
votes
1answer
589 views

Cleaning shapefiles with islands in GRASS GIS

This may be very simple, but I'm new to GRASS GIS. I have a large shapefile containing global species ranges, which needs topological cleaning. I imported this into GRASS GIS 6.4.3 using v.in.ogr (a ...
0
votes
1answer
108 views

Analysing a network distance to two or more points using GRASS or QGIS

I am doing a piece of analysis work looking at distances along a network in GRASS. Most of the analysis involves finding which parts of the network are within 600m of a series of points. GRASS does ...
0
votes
1answer
58 views

grass on ubuntu cannot import globalvar

I installed GRASS GIS 6.4.3 on Ubuntu Precise 12.04 by sudo apt-get install grass grass-doc, as recommended by the Wiki. It runs with the wxpython GUI, but when I use any command (like r.in.gdal or ...
0
votes
1answer
67 views

How to use the Cartographic Composer of GRASS 6.4.3?

Following on from my previous question (which was, again, how to use the Cartographic Composer)... I've got a GIS in GRASS. I need to print various bits of it. Problem is, it needs images on it ...
0
votes
0answers
118 views

gdalbuildvrt ------— Problems with binary rasters used by grass

r.in.gdal is used for importing tif images in grass environment and they were changed to binary by default. I am trying to make a stack from them but unfortunately grass does not see my rasters ...
0
votes
1answer
227 views

Importing SRTM Data into Grass

I am having issues importing an SRTM HGT file into Grass. I first made a new location as the instructions from this Grass Newsletter Tutorial states. I then went to the download site and downloaded ...
0
votes
1answer
92 views

How to import r.in.gdal from WCS (only region extent)

Can I import WCS-Data only for the current region by r.in.gdal? I tried to import raster data from my WCS into GRASS GIS, using r.in.gdal as proposed in ...
0
votes
0answers
38 views

TIF file creation from shapefile in GRASS?

Does anyone have any idea how to get around this problem? I've been looking for a solution to no avail. I'm trying to convert a shp file to a grid, and the tif is hanging up. Output raster layer: ...
0
votes
0answers
46 views

Unable to set pg as default backend with osgeo4w GRASS

I am trying to set PostgreSQL as default backend for GRASS, but cannot manage to get it right. Working with GRASS 6.4.3 print g.run_command('db.connect', driver='pg', flags = 'c', ...
0
votes
0answers
80 views

Calculating vector statistics in GRASS

I have a points layer, each of points have an year attribute and I want to count how many points in each year. I use GRASS-GIS and its v.univar function: v.univar -e map=mod14_hmao column=year ...
0
votes
0answers
102 views

How to simplify osm2po's routable graph?

I'm building a pgrouting routable network thanks to osm2po, the problem is that my network is too big. Indeed I want to create isochron and 1 node = 1 canvas circle, so I don't want too many nodes. I ...
0
votes
0answers
56 views

Problem with GRASS in QGIS

I am trying to import a vectorlayer to GRASS from QGIS. I get an error and hope someone here can help. Been trying to fix it for hours, but come no closer to a solution..... This is the error I get: ...