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.

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4
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1answer
36 views

How do I count the number of vector lines that pass though a given raster cell?

I am working on a project (currently in GRASS7 though I'm not against exporting to Arc or R or other software if necessary) where I am generating thousands of shortest cost paths (using the r.walk and ...
0
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0answers
9 views

How to calculate the 3D length of line segment in QGIS?

I've been looking through all of the GRASS commands in the QGIS 2.10 processing toolbox and it seems like one of these must be able to do this but I haven't found one yet. There is 'v.sample' which ...
1
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3answers
51 views

Grass toolbar for QGIS 2.10

I don't see the GRASS toolbar in QGIS 2.10 (Pisa). There are still GRASS commands in the Processing toolbox. I know there was some upgrade of GRASS for 2.10. Is the toolbar not available anymore? If ...
3
votes
1answer
23 views

Simplify / generalization of flow lines

I'm trying to make a model of surface runoff of rain water. I'm using GRASS GIS function r.flow, which generates nice smooth lines of runoff. What I need is edit these flowlines someway to avoid ...
0
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1answer
11 views

GRASS r.inund.fluv example of input files

Does anyone have an example of input files for the GRASS r.inund.fluv add-on that can be shared. I am asking because I am getting some errors when I am trying to run an the files that I created and I ...
2
votes
1answer
354 views

How to begin with tool development for GRASS gis or QGIS GRASS

I wanted to begin with customized tool development in Grass GIS or QGIS grass. How should i begin in to develop the tool. I search a lot in google search engine for begin with tool development in ...
-1
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1answer
76 views

Is it possible to import/run AML script into GRASS?

I have an AML script that has instructions to import tmp files of (grid, network, basin...) is there any way to run the script in GRASS? I tried to converted to Python but I couldn't do it for the ...
0
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0answers
35 views

Raster Not Loading into Map Display - GRASS

I am very new to GRASS and I have been trying to load a raster using just the GUI. I have set my project to the projection of my .tiff file and extents. Using file > import raster I select the .tiff ...
1
vote
1answer
281 views

How to interact with GRASS GIS vector map topology “level/layers” from terminal/command line?

Is there anybody out there that can maybe assist in the most simplest form of code to call on command line to "export topology" (which is level 2 information in GRASS) as separate spatial data, as ...
4
votes
1answer
40 views

What is the “t” in i.landsat.toar

I'm using GrassGis 7.0.0 for Landsat imagery. In the description of i.Landsat.toar under dos3 and dos4 is: TAUz = exp[-t/sin(e)] What is "t"? I cannot find any description about what it is. Can ...
2
votes
2answers
294 views

How to keep (complex) color table when exporting from GRASS

I understand how to work with color tables within GRASS - but is there any way to preserve color tables when opening the raster in a different program? For example, I created a color table in GRASS ...
1
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0answers
19 views

Identify nodes in GRASS

Apologies if this is a really basic question but I have been unable to sort this out: How do I identify nodes in GRASS and/or QGIS? Specifically, I am running a Steiner analysis and get the following ...
2
votes
1answer
833 views

Create a 3D surface from xyz csv using GRASS

Apologies if this is a repeat question guys. I am trying to create a 3D bathymetry surface from xyz data. There is approximately 300,000 points with lat, long and z (depth data). The data is sonar ...
2
votes
0answers
30 views

Where is the “Add vector layer”-button in GRASS 6.4.4. plug-in QGIS 2.10.1?

I've just downloaded and installed the new version of QGIS 2.10.1 with GRASS 6.4.4. When opening a new GRASS mapset and importing layers, I missed the button "Add a new vector layer". I've updated ...
0
votes
1answer
34 views

Using GRASS7 algorithms via WPS - best practices

I need to set up Linux server (Debian or Ubuntu), which provide GRASS7 algorithms via WPS. I have some attempts with 52°North WPS, but without any success. Also there are many other ways how to do it, ...
2
votes
1answer
53 views

Processing algorithm fails from Python script

I'm trying to write a Python script performing a geoalgorithm. What is surprising me is the following: I first test the algorithm by QGIS (2.8) interface. In my case, the GRASS interpolator ...
4
votes
3answers
177 views

3d vector and geometry operations in open-source GIS

There is some really good open-source software available to work with 2D vectors. For example QGIS has operations like buffer / clip / dissolve / select by location / join attributes by location... ...
2
votes
2answers
236 views

Issue while running grass from subprocess

I have a map based web application using geodjango. I needed to display the crime hotspots within a selected polygon area. I found that v.kernel is very good for generating heatmaps/hotspots. So in my ...
3
votes
1answer
37 views

Is it possible to have v.in.lidar without compiling GRASS?

I already have installed libLAS like this: sudo apt-get install liblas-bin And Ì have installed GRASS GIS 7 from the ubuntugis-unstable repository. Is it possible v.in.lidar without compiling ...
1
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0answers
4 views

Error executing GRASS function i.topo.corr from R [closed]

I am attempting to topographically rectify Landsat data using the i.topo.corr GRASS function from within R using the rgrass7 package. My code is as follows: execGRASS("i.topo.corr", flags = "i", ...
4
votes
1answer
151 views

Grass NVIZ has no output in QGIS 2.8.1 ubuntu 14.04

I am trying to use the Grass7 NVIZ algorithm from the QGIS 2.8.1 toolbox, on ubuntu 14.04. I have enabled Grass7 in the QGIS processing preferences. I have compiled Grass7 from source, and Grass ...
1
vote
2answers
63 views

GDAL/QGIS broken Ubuntu 14.04

I think I've managed to bust GDAL after (I think) installing Grass7. I had previously built GDAL (1.10) from source with a bunch of additional drivers. When installing Grass7 GDAL 1.11 was installed. ...
0
votes
1answer
34 views

How can i import raster image to GRASS GIS without losing RGB Values?

I am using GrassGIS 6.4.2, How can I import raster data to GrassGIS without losing RGB Values? The raster image format is TIFF, the below commmand is using to import raster image: r.in.gdal ...
5
votes
1answer
185 views

Create raster with grid cells values based on area covered by polygons

I have a polygon data with area covered by the forests (data is here - https://www.dropbox.com/s/zgckliydalljw6a/sp_data.zip?dl=0). I want to convert polygons to raster. The value of each grid cell ...
-2
votes
0answers
10 views

Importing raster data in to grass gis [duplicate]

0 down vote favorite I am using GrassGIS 6.4.2, How can i import raster data to GrassGIS without loosing RGB Values? raster image format is tiff, the below commmand is using to import raster image ...
2
votes
0answers
36 views

how to orthogonalize building outlines

I'm looking for a way to orthogonalize building outlines which I've extracted from a high-res DEM. I'm using the FOSS GIS stack (QGIS, GRASS, SAGA, PostgrSQL, PostGIS) and can code in Python (or ...
1
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0answers
29 views

Elevation data from 3D shapefile of buildings to raster DEM

I have acquired LoD2 building models in the 3DShape format (Polygon ZM). This LoD2 data needs to be prepared for a R-script of solar irradiation calculations on roof surfaces, but which can only ...
2
votes
2answers
64 views

Suitable Raster processing methods to extract field boundaries from images

I'm trying to extract field boundaries and features from a lot of aerial images of agricultural land - and avoid digitizing these features manually. I've managed to get a crude raster file of the ...
1
vote
1answer
38 views

What's difference between Topology and Check Validity in QGIS?

I would like to know what the difference is between the Topology Checker and Check Validity tools? Is there anyone who knows of a good document or tutorial that explains functions of these tools? ...
1
vote
1answer
109 views

Unable to start modules in QGIS GRASS plugin (GNU/Linux Debian)

Recently, the Toolbox of QGIS GRASS plugin can't find modules in my GNU/Linux Debian. When I click on any module, the toolbox reports the message: Cannot find module x.xxx and, after, I have the ...
3
votes
1answer
26 views

QGIS Convert bathymetry shapefile from fillable to strokeable

In Java I would like to stroke the bathymetry depth lines instead of filling the area. I'm starting with the Natural Earth Bathymetric Data: ...
1
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0answers
67 views

Grass 7 no longer works via the Processing Toolbox in QGIS

When I try to execute a Grass 7 algorithm via the Processing Toolbox in QGIS 2.10, 2.8.2 or 2.8.1, I get the following error: Missing dependency. This algorithm cannot be run :-( QGIS ...
0
votes
0answers
13 views

QGIS Training Manual - Lesson 12.2.1 (GRASS GIS) - r.colors.table module does not color raster

I am going through the QGIS Training Manual, Lesson 12.2.1 ("Follow Along: Set Raster Colors) and noticed that the 'r.colors.table' GRASS module did not color my DEM raster layer which I imported via ...
1
vote
1answer
16 views

Creating input node file for V.net.salesman in GRASS?

I have imported line vector layer and point vector layer(12 points) to grass using v.in.ogr. Now i want to use v.in.salesman to find shortest path between these 12 points, but i couldnt input ...
2
votes
3answers
473 views

Raster map in different zone () than region ()

I am new to QGIS (just installed QGIS 2.0.1) and am having problems running any spatial analysis tools. I followed the instructions on how to call GRASS tools into QGIS, but when I try to run the ...
1
vote
0answers
40 views

Compile QGIS from source (with Grass)

I recently decided to reinstall QGIS and build against the latest version of GDAL - something I have been putting off for ages because I suspected it would be a nightmare. Lo and behold it has been, ...
0
votes
0answers
8 views

GRASS problem - r.viewshed.cva addon

I'm a very beginner at GRASS. I'm using GRASS 7.0 and I tried to install r.vieshed.cva extension. When installed, if I type it in the command line, it appears "r.viewshed.cva" is not recognized as ...
2
votes
1answer
234 views

How to iterate GRASS region definition?

I am using GRASS r.skyview command (v.7, Windows) to determine "urban canyon effect" on pollution due to the presence of buildings. The command nicely works, unfortunately I need to process a very ...
1
vote
0answers
51 views

Removing pseudo-nodes using QGIS Sextante plugin?

I have a road network (vector) that i'm interested in carrying out some space syntax analysis on. Predictably my GIS data is in a pretty terrible state. For example, there are a bunch of roads on the ...
0
votes
0answers
11 views

Grass 7 import shapefile problems

I'm just messing about with Grass 7 (installed fine on Ubuntu 14.04 - well no errors at least). I'm trying to import a shapefile using v.in.ogr and when presented with the dialog box, browse for my ...
0
votes
0answers
37 views

Converting a (WAsP) vector map to a raster map with GRASS GIS

i'm quite new to GIS and i need to convert roughness data which is available in a vector format to a raster format. The final data should be on a simple 2-dimensional uniform grid with a constant grid ...
0
votes
0answers
40 views

registering MODIS in GRASS as space-time dataset

I have a problem using the space time module in GRASS GIS (7.1 for Ubuntu). I have a MODIS time series with 8 day interval, so 46 images per year. So I created a file (filelist_grass.txt) containing ...
2
votes
0answers
50 views

Drawing “proportional” buffer using QGIS or GRASS?

I'm working on aquatic vegetation and have a shapefile representing floating vegetation in a lake. By some studies, we know that submerged vegetation extends for a certain extension based on floating ...
1
vote
1answer
206 views

Running GRASS functions in QGIS 2.4 from python console

I am using qgis 2.4 and i am looking for the "easiest" way to execute e.g. the r.in.gdal function from the python console in qgis. Specifically for r.in.gdal, I could not found this function in ...
0
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0answers
48 views

Why is r.sim.water out of memory (ERROR: G_calloc) in GRASS GIS?

I'm having trouble with GRASS GIS. I'm new to GRASS GIS, I have played around and also searched the internet and the Wiki, but found nothing really helpful, so this is my last chance :) I wanted to ...
0
votes
1answer
24 views

Error when installing a GRASS addon!

I am trying to install r.inund.fluv on Linux to produce inundation maps but I am getting the below error. Note that I have a Fortran compiler. Any help with this matter would be highly appreciated. ...
1
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0answers
57 views

Error: GRASS 7.0 and QGIS 2.8.1 in Linux Mint from the ubuntugis-unstable

I have installed GRASS 7 and QGIS 2.8.1 from the https://launchpad.net/~ubuntugis/+archive/ubuntu/ubuntugis-unstable (Trusty 14.04) in Linux Mint 17.1 64bit(sudo apt-get install postgis libgdal1h ...
1
vote
1answer
36 views

How can I create polygons for a 3D map from a DEM in grass/qgis

I have a SRTM 30m DEM of my area. I want to create a physical 3D terrain map from it (from felt, 3D printer, you name it). I have two questions about this process: With grass r.contour I created ...
0
votes
0answers
31 views

GRASS 7 (python:14221): Gtk-CRITICA Linux Mint

I installed GRASS 7 and QGis from the https://launchpad.net/~ubuntugis/+archive/ubuntu/ubuntugis-unstable (Trusty 14.04) in Linux Mint 17.1 two weeks ago (sudo apt-get install postgis libgdal1h ...
3
votes
1answer
548 views

Solar irradiation calculation using r.sun

I am trying to compute the global solar irradiation for a region and the run times seem to be a bit too high. I have as inputs a Digital Surface Model with the buildings and a Digital Terrain Model ...