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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100 views

How to build a GRASS network with node IDs from the line dataset?

I have a dataset of street network links (line geometries). Each network link has a link id, start node id, and end node id attribute. I want to use this network in GRASS, so after importing the ...
2
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1answer
42 views

Looping for importing and interpolating a lot of LIDAR files?

I'm quite new to Grass Gis and I'm trying to make DEM (digital elevation model) for modelling flooding. I have 170 *.xyz files, which need to be scanned for extents (r.in.xyz -s input=...\filename.xyz ...
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0answers
325 views

QGIS 2.8 problem accessing GRASS commands

QGIS 2.8.1 Win7 64 bit installed with osgeo4w-setup. I’m trying to run GRASS commands on a LIDAR raster layer but I get the following message: Missing dependency.... GRASS not installed in your ...
4
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2answers
933 views

How can I calculate the vertical distance to the nearest water?

Summary: I would like to create a raster where each cell contains the vertical distance to the nearest water (a decent approximation would be acceptable). The problem is that I'm not sure how to go ...
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0answers
30 views

Command Grass in QGIS not work

When I use r.contour or other Grass commands in QGis, I have this error message. Why?
1
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1answer
21 views

hdf-eos5 file format import in grass

I want to import AURA-OMI ozone level3 data which is available from http://giovanni.gsfc.nasa.gov/giovanni/ .The data is in hdf5 format. The extension is .he5. Do anyone know how to import in grass. ...
1
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1answer
257 views

No such file or directory PERMANENT\\MYNAME from Python+Grass?

I have an existing Python script that processes raster images with Gdal / Numpy. Now I want to extend the script with Grass. The python script is developed on Windows 7 with Eclipse/Pydev. The script ...
0
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0answers
35 views

What's the best neighborhood size to smooth the ASTER GDEM v2, resampled at 1m res, in GRASS with r.neighbors?

Basing on your experience, what neighborhood size could be a good compromise to smooth the ASTER GDEM v2, resampled at 1m res, without affecting too much the edges and the valleys? I have to realize ...
1
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1answer
62 views

What's the right way to calculate the scale parameter value for r.relief in GRASS?

I have a little doubt about the way I should calculate the value of the "scale" parameter in the r.relief command in GRASS. In the description section of the r.relief page of the GRASS manual I read: ...
0
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3answers
31 views

Unexpected result converting a vector to a raster in GRASS 7.0.0

My purpose is to create a DEM raster in GRASS 7.0.0 starting from a shapefile containing contour lines. The attributes table has a field named QUOTE_INT containing the elevation as integer. I ...
0
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1answer
88 views

Running Grass7 in conda environment?

I have Anaconda Python Distribution (Python 3.4.3 :: Anaconda 2.1.0 (64-bit)) installed on Ubuntu 14.04. I would like to create a conda environment for running Grass 7. To do that I used: conda ...
2
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0answers
86 views

Performance difference between focal statistics (ArcGIS) and neighbor (GRAS or QGIS)

I tested minimum, maximum, and average neighbor (circle radius = 161 pixel) using ArcGIS, GRASS and QGIS: ArcGIS (10.1): it takes only one minute GRASS (6.4.3): it takes 123 minutes for every output ...
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0answers
61 views

GRASS GIS r.walk issue

I have been playing around with GRASS GIS to do a simple cost analysis of getting from point A to point B. I have a DEM clipped to the study area, a raster containing the friction costs, as well as ...
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0answers
28 views

How to smooth a shaded relief map created with the command r.relief in GRASS 7?

How can I smooth a shaded relief map created with the command r.relief in GRASS 7? I read about the plugin r.denoise but I can only find it for GRASS 6... Thanks in advance. Bryan
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18 views

Is there a max number of cells which r.surf.contour can interpolate in GRASS?

Nothing less, nothing more... I'm wondering if there's a max number of cells which r.surf.contour can interpolate in GRASS, because I have to interpolate a region of 24000 rows x 23000 columns but I ...
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0answers
17 views

Reading L1B ASTER in GRASS using r.in.aster

I'm having a problem getting an ASTER L1B to be read in GRASS using r.in.aster. The output the command shows this: (Wed Apr 8 17:49:03 2015) Command finished (1 sec) (Wed Apr 8 17:49:37 2015) ...
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0answers
91 views

Grass Processing tools via QGIS : v.clean snap, chdangle, and rmdangle

Using QGIS 2.6 Grass Processing tools, I'm trying to clean up topology on a water network layer. I noticed topological errors when first trying to break all lines on intersections using v.clean break. ...
2
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2answers
126 views

Is d.mon xN deprecated in GRASS in favor of something in the wxGUI?

I'm trying to learn command-line GRASS (6.4.3) using the KyngChaos binaries on a Mac (10.8.4) from Neteler and Mitasova's book, Open Source GIS: A GRASS GIS Approach (3rd ed.). I've learned from this ...
2
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1answer
37 views

Generate a raster with a uniform value using QGis

I'm working on a project using the qgis-modeler and i want generate a raster with a uniform value. i'm using r.surf.random function of GRASS which need min and max value but i want have only one ...
9
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1answer
661 views

Kriging on GRASS+R - cannot allocate vector of size 146.5 Mb

I'm trying to do a groundwater elevation map with an Ordinary Kriging on R, but always resulting on the lack of memory cannot allocate vector of size 146.5 Mb allocation (windows xp 32bit). ...
5
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3answers
1k views

Error when creating a new mapset with GRASS in QGIS

When I try to create a New Mapset with the GRASS plugin in QGIS I get an error or the program crashes. QGIS 2.6.1 (32-bit install, Win7). QGIS crashes completely when clicking "Finish" in the New ...
0
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2answers
84 views

Ls factor, flow accumulation, watershade, relief in Quantum GIS 2.2

I'm a beginner quantum gis. I want to make the LS factor of 30m DEM that I have merge and set the projection in wgs 84/UTM zone 49S (EPSG ; 37249). I'm having a problem when trying to create relief ...
1
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1answer
57 views

Old question without answer: R.Neighbors with large neighborhoods?

I'm working on the same theme as User 32882, and I'm new here. I have the same problem, and update his question with more details. Old question: "I'm running into problems running the r.neighbors ...
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0answers
89 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 ...
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2answers
109 views

Extract Elevation of Points from DEM using Python QGIS or GRASS

I am utterly new to GIS, so please bear with me if I am providing incomplete information here. I have a DEM file (.dt2). What I am looking to do is as follows: take a series of points specified as ...
2
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3answers
107 views

Find coordinates of given raster value

I would like to get the coordinates of a raster cell with a given value. I suppose many cells can take the same value, in which case several coordinates should be returned. In my first problem I'm ...
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0answers
105 views

Pansharpening Landsat 8 tiles in Grass 7

I am trying to get some nice looking RGB images for visualization purposes, mainly using as background maps, from the Landsat 8 archive. I was following the tutorial provided by Markus Neteler at ...
0
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1answer
75 views

Conditional calculation - QGIS Raster Calculator or GRASS r.mapcalculator

Is it possible in QGIS either directly or via plugins to do a raster calculation including an if statement? e.g., if raster1 > 0.3, then raster 1 * raster 2, else raster1 x raster3...something like ...
1
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0answers
24 views

wps-grass-bridge misses essential GRASS tool

I set up a Web Processing Service with 52°North and GRASS (using the wps-grass-bridge). I get a similar result like in the online example here: 52°North WPS Demo I assume it would be similar with ...
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0answers
17 views

QGIS WPS plugin misses one parameter

I set up a Web Processing Service with 52°North and GRASS (using the wps-grass-bridge). All went smooth and I get a proper DescribeProcess for i.cluster. As you can see, I need to give the parameter ...
1
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1answer
16 views

Where to get GRASS module r3.out.vtk?

I'm looking for the GRASS module r3.out.vtk. It's featured on the GRASS GIS manual : http://grass.osgeo.org/grass64/manuals/r3.out.vtk.html But it's nowhere to be found, and neither are r.out.vtk and ...
2
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3answers
1k views

How to delete rings automatically using QGIS/Grass

I'm cleaning up a (very) messy shapefile in QGIS/Grass. I now have several large polygons with numerous (100s) of small rings. Is there a quick and easy way to remove/ fill all these small rings. ...
3
votes
1answer
404 views

GRASS GIS 7 in QGIS 2.6.1, Windows 7 64bit - Missing dependency

I am using QGIS Brighton 2.6.1. Today I have installed Grass GIS 7.0.0 RC2 to try its topology functions in QGIS. I have activated the provider, set the paths, but everytime I try to use any Grass ...
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0answers
48 views

3d model to point cloud

Excepting FME, is there a way to convert 3d model to point cloud?
0
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0answers
62 views

develop rooftop solar radiation potential from 3d buildings model (3dm)

Need to create solar cadastre without having LIDAR data. Have 3d buildings model in .3dm (150 000+ roof surfaces, 500 000+ facade surfaces unmapped, dtm 15x15m) with a lot of multipatch geometry ...
2
votes
1answer
52 views

View feature space for multi-band files

I am trying to plot a feature space (scatter plot) for some SPOT images in QGIS 2.8.1. I know a histogram is available in the file properties, but I want to plot eg. Band 1 vs Band 2 to see the ...
3
votes
2answers
81 views

Loading Grass 7.0 vectors in QGIS broken?

Running QGis 2.8.1 in Win7 (64bits), installed through OSGEO4W. When trying to load a Grass 7.0 vector file in QGis, the program will simply crash without any notice. I can load old Grass vectors ...
9
votes
4answers
1k views

Are there any open source tools to detect and fill sinks on a DEM?

Are there any open source or inexpensive tools to detect and fill sinks on a DEM? ArcGIS Spatial Analyst is just out of my price range.
2
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2answers
83 views

Difference between FCELL, DCELL and CELL in GRASS GIS?

Can anyone clarify for me please the options in the "precision" parameter when calculating slope, aspect and curvature in GRASS GIS. What is the difference between FCELL, DCELL and CELL?
1
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1answer
166 views

How to fix the grass7 package available from the ubuntugis-unstable PPA?

Out of the blue, grass stopped functioning this morning on one of the Ubuntu 14.04 systems I use: $ grass Starting GRASS GIS... python: can't open file '/usr/lib/grass70/gui/wxpython/gis_set.py': ...
2
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0answers
77 views

QGIS-GRASS firespread simulation module [closed]

I'm trying to do some fire spread simulations in QGIS with GRASS fire spreading simulation module. QGIS ('Processing Toolbox' > 'Geoalgorithms' > 'Misc' > 'Fire spreading simulation') GUI. Already ...
0
votes
1answer
89 views

Removing salt and pepper effect

In a land cover raster (categorical map) that is a product of classified satellite image, what is the best way to remove "salt and pepper" effect from the image after classification. I am not ...
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0answers
55 views

QGIS, GRASS and WINDOWS 8

Good morning, I'm using QGIS 2.8.1 (Wien) on Windows 8 x64 bit. When I'm trying to lunch the GRASS plugin (6.4.3), Windows shows me the error g.mapset.exe has stop working, then after some times, ...
0
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1answer
171 views

Empty raster returned after GRASS i.atcorr with Landsat8 data

I've searched at length on previous forums but no solution seems to work for me. I'm trying to run the i.atcorr module on GRASS (version 6.4.3 on a Macbook Pro, Mavericks OSX) with Landsat8 imagery. ...
0
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0answers
20 views

Using r.neighbors on borders

I have a raster file with pixel size 30 x 30. At the upper border there is half row with "no data" pixels. I want to use the mode function to replace them. I have only thought r.neighbors (from grass) ...
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0answers
50 views

Pansharping Problems with Landsat8

I downloaded Landsat 8 Data from Earthexplorer and used that Workflow: http://courses.neteler.org/processing-landsat8-data-in-grass-gis-7/ Now I want to pansharp the Landsat 8 Datas. For that I used ...
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0answers
31 views

Is it right to remove salt & pepper effect from a product produced by clean images?

I have two images from classification (different years) and I want to find the changes of land cover . I have cleaned the two images (salt and pepper). When I create a cross product of the category ...
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0answers
25 views

GRASS_INFO_ERROR(16605,1) while running a GRASS tool

I have a fresh install of QGIS 2.8.1 with the GRASS plugin on Ubuntu 14.04. I opened the mapset I've created in QGIS 2.6.1 on Windows 7. Then I tried to run v.in.ascii Grass tool and I got following ...
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1answer
133 views

How to visualize a point cloud in 3D with GRASS?

I'm new with qgis and grass so I'm sorry if there is a straightforward answer for this question but I can't seem to get it done. I've imported a pointcloud into qgis from a datafile. Now i'd like to ...
1
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1answer
63 views

G_realloc: unable to allocate 46320000 bytes of memory while managing large .xyz through v.in.ascii

I tried to convert large (~180MB) .xyz file into vector through v.in.ascii in QGIS Brighton (2.6.0) Grass plugin (it should be Grass version 6.4.3). The "primitive registration" stage lasted very long ...