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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Importation of .csv on grass gis converts numeric data to string data

When importing a csv file on grass7, the numeric data is converted into a data of type string. My csv looks like this : id_core value 1 F1 83.0611472396 2 F2 98.8584345936 3 F3 ...
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112 views

Use of Grass and R w.r.t. Land Use Prediction

In my data mining term project I need to conduct a work on geospatial data related to a big city to show possible urbanization fields in next years. I've used GRASS lately on other projects so I'm a ...
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195 views

Grass 6 extension installation in Grass 7 error

I am trying to install the extension r.roughness from the Grass 6 repository, but in Grass 7. When trying g.extensions, the error "make: * No rule to make target ...
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180 views

Add-ons on GRASS (win7)

Can someone help me to install an add-on for GRASS 6.4.3RC3, on Windows 7? I tried several approaches, but wasn't able to install the add-on. I found several topics here and on the web but the ...
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2answers
175 views

contour lines from point shape attribute

I have a point shape file and one of the attribute refers to the altitude. Is is possible to obtain a contour lines shape file in GRASS?
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56 views

GRASS: shift point locations in a random direction

I have a vector map that contains 100 points. For each point, I would like to shift it 250 units in a random location. It's easy enough to shift all points in a specified direction using v.edit ...
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517 views

import grass.script as grass under windows 7

OS: Windows 7 64bit GIS: QGIS 1.8 (qgis.org/downloads/QGIS-OSGeo4W-1.8.0-2-Setup.exe) I have created a plugin for QGIS, with the QGIS plugin builder. Now i would like to import grass.script into ...
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604 views

How to invert polygons (or other options for exterior styling)?

I have a shapefile containing many polygons that I want to use to mask a raster. I have tried gdalwarp -cutline <shapefile> -crop_to_cutline -srcnodata -9999 -dstnodata -9999 ...
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726 views

QGIS, Euclidean distance analysis [duplicate]

i wanna generate euclodian distance map for my road data. I 'll use it for multi criteria analysis. I can get it by using Arcgis Euclodian Distance tool but i wanna generate it in QGIS environment. I ...
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157 views

How to remove terracing from Civil3D GeoTIFF export?

I've received a GeoTIFF DEM that was exported from Civil3D and at every contour there is a distinct terrace created when I process an aspect or slope in QGIS with the GRASS plugins. I've looked ...
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125 views

Error using Grass v.net

I'm trying to connect my network to a points layer with a threshold of 4500 meters. I have about 11000 or so entries in my polyline and about 24 in my points layer. I have alreday used v.distance, ...
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318 views

Installing GRASS on MINT 14?

I'm very new to mint/linux/GRASS and have no clue how to deal with these errors. Can I just change the URL somewhere? Here is the simplest reproducible command to produce a failure: sudo apt-get ...
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121 views

Set certain amount of pixels to 1 inside of a polygon (GRASS)

I have a rather coarse vector map with polygons and want to calculate a (sufficiently) finer raster map defined by spatial extension and resolution. Every polygon of the vector map has a value ...
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204 views

Why is transparancy of GRASS rasters missing when imported into QGIS?

I have a raster map in QGIS imported from a GRASS mapset with the QGIS GRASS plugin. The problem is that I have null() cells in the GRASS map that appear "colored" in QGIS. How can I set the ...
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79 views

Hydrograph in GRASS

How to make hydrograph for a basin in GRASS? While surfing the GRASS home page, I came to know that some time back in GRASS 4.x a command r.water.fee exist. I understand, it is missing in GRASS 6.4. ...
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107 views

How to extend lines in Grass

I have a set of vector lines in grass which I need to convert into polygons. However, because of bad base data, the polygons don't always close. To fix this, I need to extend each disjointed line by ...
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621 views

Python script for GRASS - executing from PHP

I wrote the following python script: #!/usr/bin/env python import os import sys gisbase = os.environ['GISBASE'] = "/usr/lib/grass64" gisdbase=os.path.join("PATH") location=LOCATION NAME ...
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4answers
463 views

Determining gradient of road segment

I've a shapefile of roads data. It contains information about terrain of road segments, i.e., hilly, flat, undulating, etc. I want to determine gradient of every road segment. I know this might ...
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77 views

Is there a way to access ps.map in python?

i am wondering whether its possible using python interface to load layers and edit them in Print/Cartographic Composer without displaying, and finally export to PDF? something that can be done via ...
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226 views

v.dissolve renames the attribute table column and does not produce a dbf

When I run v.dissolve on my vector... v.dissolve --o input=pass2@mapset1 layer=1 column=fttcp output=pass3 The dissolving appears to work but the column name in the attribute table has changed from ...
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464 views

r.sim.water G_malloc error

I've been trying to run r.sim.water on a 3 meter LiDAR-generated DEM I have, but keep getting G_malloc errors: r.sim.water --verbose elevin=meterDEM.final@Sediment_Simulation ...
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289 views

Automatically apply topology rule to only selected portions of a .shp file?

I am looking for some examples/tutorials on how to apply a topology rule to only a selected portion of a shp file using a script in ArcGIS/GRASS. Using ArcGIS seems to always require an interactive ...
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134 views

Blank Vector Selection Dropdown in QGIS GRASS Plugin

I realise there are some issues which getting vectors into the GRASS module in QGIS, but is the behaviour i am getting expected? I have loaded the vector shapefile via GRASS, closed G and reopened ...
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259 views

How can GRASS export an .flt file?

I am using GRASS and connecting it to another application. The other application needs an FLT file of the raster map which I should export from GRASS. The other application only reads FLT files. Can ...
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222 views

Can r.mask be called from a batch file?

I am using a shell script that is called by a batch file. The shell script contains the GRASS scripts that I am using for my program. Every time I use the r.mask script, it displays the error r.mask: ...
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396 views

How to use r.patch with two maps having different colortables?

I am using r.patch to combine two raster maps in order to fill in the null values of the other. Is there a way to use r.patch but still maintaining the colortables of the separate raster maps? I do ...
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634 views

Is there any pseudocode for MFD (multiple flow direction) algorithm available?

Still stuck with the simulation system, is there any good pseudocode for the multiple flow direction (MFD) algorithm? I read a pseudocode example and implemented it, however the simulation was linear: ...
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391 views

How to compile in Fortran in order to use an add-on in GRASS?

I need to use the r.inund.fluv add-on in GRASS. I installed the gfortran compiler in order to use the script. The problem is, I do not know how to compile the files in gfortran. Im using windows Here ...
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3answers
440 views

d.out.file is not working

I'm trying to use 'd.out.file' to save the displayed map to a PNG file. It failed and produced this message: "Command 'd.out.file' not yet implemented in the GUI. Try adding it as a command layer ...
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248 views

Why is my controlling shell script not working?

I updated my post after I resolved the previous errors, but additional errors were produced. I want to create a controlling shell script that contains water.mapcalc within it. The problem is, I do ...
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396 views

How to link an application to grass?

I am creating an application (C#) and I want to connect it to GRASS, mainly run grass scripts from my application. This might seem to be a repeated question however I am thinking of the possibility ...
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684 views

GRASS v.out.dxf 3D into AutoCAD

So continuing with my last question (Create 3D dxf with OGR) I have decided to give the GRASS option a go. I have imported my polylines into GRASS using v.in.ogr and converted them to 3D using ...
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302 views

Error in r.terraflow

I used r.terraflow.short in GRASS, but it displayed this error: r.terraflow.short elevation=raster_bulacanElevation \ filled=raster_bulacanElevationFlooded1 \ ...
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158 views

How to resolve GRASS error “Execution failed: 'gproj -p' ”?

I installed the WinGRASS-6.4.0-1-Setup.exe 55M from http://grass.osgeo.org/grass64/binary/mswindows/native/. I'm using a x64. After installation, I tried opening the demoLocation but it failed and ...
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15 views

How to load “soil types” in QGis?

I want to show soil transmissivity per pixel. Thus, I determine water holding capacity of each pixel (ignored other effective parameters). Respectively, I wonder, What is the soil data format and How ...
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33 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 ...
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42 views

Hydropower Calculation

I have assigned the elevation and the volume flow to each point at a river (with v.to.db and v.what.rast). Now I want to calculate the Elevation difference between each pair of points and then ...
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26 views

Calculate River Runoff Volume (Q) with GRASS

I want to calculate Hydropower between points at a River. I already created a Rivernetwork and the Accumulationmap (without weighting) with r.watershed. My next Step was to set equivalent points along ...
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18 views

What is the background processing of rainfall thresholding?

I want to create a flood map using Quantum GIS. First of all I create catchment area (flow accumulation). Then, I delineate a Channel Network by applying a threshold to flow accumulation. So I want to ...
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25 views

How to do a 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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22 views

problem with running raster calculator in grassgis

When I was trying to do NDVI with grassGIS I faced a problem. I cannot run the raster calculation. When I looked to the command console I see that (Sat Feb 21 12:41:58 2015) r.mapcalc ddes = ( ...
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6 views

GRASS GIS: Network analysis doesn't work correctly

I got a problem with the Network Analysis function v.net.iso in GRASS. I tried it so many times but the function doesn't work correctly. I tried to calculate isolines via the function v.net.iso, based ...
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17 views

Raster Mosaicking GRASS Issue

I have a project where I have to download DEMs from USGS and mosaic them. So I downloaded them from EarthExplorer and imported them into GRASS. When I start the GUI version of r.patch using the ...
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10 views

r.water.outlet returning blank raster

I am trying to delineate a watershed using r.water.outlet. I have created a flow direction raster using r.watershed (threshold = 50) (cell size is 300m). I use this flow direction raster in ...
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22 views

Displaying a Digitial Elevation Model using GRASS GIS draped by an RGB Raster

I have the following: Digital Elevation Model from SRTM LANDSAT Imagery from the same area I wish to display the DEM draped with the raster band combination (3,2,1) using GRASS GIS. My ...
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28 views

Unable to find a specific GRASS add-on in QGIS

I would like to use the r.xtent add-on made for GRASS GIS (http://svn.osgeo.org/grass/grass-addons/grass6/raster/r.xtent/description.html) in QGIS using the GRASS plugin, but I can't seem to find it. ...
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43 views

Error when using r.watershed

When i am calculating LS Factor using Grass r.watershed the error "Raster map or group not found" (image below) keeps turning on. I don´t understand why this error happens if i am using a elevation ...
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46 views

QGIS and GRASS r.fill.dir processing times

I am new to the open source software and have performed analysis in ArcGIS in the past. I am learning as I go on this processes for OS. I am trying to calculate stream order (strahler) on a 1 gig ...
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22 views

Calculate raster mode with r.mode - problem with decimals

I am working with a raster file that represents the percentage of vinyards by commune (e.g., municipality) in a region in France. The statistics were calculated for each commune based on surveys from ...
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59 views

How to extract percentage of land cover from a raster according to multiple shapefiles?

I have a raster map that represents land cover of a region, and different shapefiles (total 120) in the same region. I want to know the percentage of every land cover for each shapefile. For example, ...