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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153 views

v.surf.idw on grass return : no data points found

I'm a newbie with grass and I'm using grass (6.4.3) with the GUI... running Ubuntu 13.04 for what it's worth. Here is my region : projection: 99 (Lambert Conformal Conic) zone: 0 datum: ...
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2answers
133 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 ...
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72 views

Error message starting gis.m in GRASS

I finally broke down and bought Neteler and Mitasova's book, Open Source GIS: A GRASS GIS Approach, because I need to learn command-line GRASS. On trying to work through the book's examples, I'm ...
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1answer
404 views

How to script map production in GRASS?

I'm trying to automate my production of maps with GRASS. What I want to do can be described in fairly generic terms: I have two layers (one vector, one raster), which will be identical in every map. I ...
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96 views

How to Configure sextante in Qgis 1.9 ubuntu

I am using Ubuntu 13.04 and the most up to date version of Qgis 2.1.0-Master. I am trying to get sextante to work correctly and have a hard time. Specifically SAGA 2.1.0 and GRASS 6.4.2 will not ...
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183 views

GRASS GIS related issues! [closed]

(1) How to create a multiband raster from a set of single band rasters (except when somebody talks about doing a r.composite). I attempted creating a raster3D and it turned out that it is not ...
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1k views

How do I change from lat/long to a metric coordinate system in GRASS?

Yes, it's yet another transformation question. I am working with ASTER DEM data, which is LatLong WGS84. I want to process the DEM map into an STL file for use in a CFD simulation. The script I am ...
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2answers
842 views

Why is this SRTM TIFF not visible in GRASS GIS 6.4.3?

I want to use interpolated SRTM data for Germany to generate an STL terrain map for use in a CFD application. My SRTM data comes from the OpenDEM project. SRTM data normally has voids, but this data ...
2
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1answer
61 views

Trying to extract arc information from a Suburb shapefile

I downloaded some shapefiles from the Australian Bureau of Statistics (ABS). It's basically showing a bunch of suburbs when I view the shapefile through a GIS tool. The GIS tool that I am using at ...
2
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1answer
70 views

Profile plot trouble in Grass GIS

I'm new to Grass and GIS environments in general, and I recently faced a problem when trying to get the profile plot from a DTM. When I draw the transect, instead of the plot, I get the following ...
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2answers
460 views

Is there an open source alternative to ArcGIS for Desktop's Integrate tool?

I need to snap about 1000 lines in one layer to the lines in another layer (there are about 5000 lines in the second layer). The lines to be snapped are about 15 map units away from the base layer ...
2
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1answer
867 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 ...
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4answers
906 views

Unable to load GRASS plugin

I upgraded from QGIS 1.7.0 to 1.8.0, including updating GRASS to version 6.4.3. Since then, GRASS isn't any longer listed in the Fetch Python plugins. I uninstalled and re-installed the whole package ...
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1answer
825 views

Using Landsat 8 for quantitative analysis - what DNs does GRASS require?

Hoping someone can short circuit a lot of exploration Landsat 8 values are stored as unint16 since the sensors work on a range 0 to 4096 whereas the L7+TM was 8 bit and had a digital number range 0 ...
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1answer
113 views

GRASS 6.4.3 Landsat processing

what are the pre-processing steps required for landsat etm+ with GRASS 6.4.3 prior to land cover change detection? The product used is L1T.
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74 views

Error Opening QGIS Lisboa Quantum Msys

I am deploying QGIS in our environment. I found the silent switch (/S) to be working, it installs the 4 default components, Grass, MSys, GIS Desktop & GIS browser. The trouble begins when a user ...
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1answer
249 views

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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103 views

How to edit a table in GRASS?

How do I edit a table in GRASS? When importing a vector into GRASS from QGIS, all the attributes are lost and I need these to continue with my analysis.
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100 views

GRASS has broken my terminal

I'm using GRASS on OS X. After installing GRASS I can no longer open my terminal to a prompt. On opening the terminal, the following line runs by itselt ...
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0answers
220 views

Covisibility with QGIS/GRASS : r.los issue

I try to use r.los for a viewshed calculation. I specify the dem (Aster DEM clipped on a 2km*2km region). I specify x and y coordinates and run the command. Nothing append. I waited for 20 minutes ...
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2answers
597 views

minimum distance from the shore (how to retrieve the “shore vertices”)

I am student of Statistics, this is my first time using GIS., I am sorry for the stupidity of the question but I browsed online and could not find a satisfactory answer. I have some spatial data in ...
2
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1answer
245 views

GRASS - v.clean Conflation - How to snap a layer to a base layer

Someone told me in this post that GRASS GIS can handle multilayer topology, what I have not found any information about. I am not a specialist of GRASS GIS so I would need help with that if its really ...
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1answer
450 views

How to batch merge rasters using FOSSGIS tools?

I'm working with QGIS 1.8 (gdal 1.9.2) and GRASS 6.4.3...but on Windows 7. I "just" want to merge my raster. I've got a folder with 50 GTiff raster from Lidar data. The aim is to merge raster ...
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2answers
190 views

GRASS v.rast.stats missing in sextante toolbox

I am new in the QGIS world and also with GRASS. I am really interested in using v.rast.stats as is doing exactly what I need. My problem is that I am not able to find it inside sextante in QGIS and I ...
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1answer
113 views

Problem with interpolation of 3D points in GRASS

I have a sample of 3D points (x,y,z) with tepmerature attribute. I can import my data as a 3D vector map. I want to create a volume of voxels by using v.vol.rst. When I use this module, this error ...
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145 views

Cannot import Grass in Console of Qgis (1.9.0 Master)

I can't import Grass in Console of Qgis (1.9.0 Master). I am guessing it is because of some Grass environment variables which are not set up correctly. However I don't understand why it is working ...
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2answers
258 views

Resolution difficulties in Grass

I have gone through similar questions to mine here, but I didn't find a solution. Please help! When cropping a raster image by using g.region & r.mapcalc, I get a new image but the resulting ...
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43 views

Why does install of add-on r.clump2 for GRASS 7 give error?

I am trying to install the add-on r.clump2 for grass7. What is wrong and how do I fix it?. Thanks The error code im receiving is the following: > (Fri Jul 5 15:13:42 2013) ...
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80 views

GRASS GIS SDTS Manipulation

Preface: I'm a total GIS noob. Flame away. I'm learning GIS in my free-time and with free resources. I realize that is likely going to force me on the learn-fast-or-giveup track, but here it goes... ...
4
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1answer
89 views

How to choose a GRASS kernel density function?

I'm starting to use the Grass module on QGIS, and I want to do a heatmap, so, I'm creating a new surface using the kernel function. But, GRASS come with 7 types of kernel functions, how do I know ...
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6answers
764 views

Tool/Algorithm for generalizing OSM-Files for printing maps

Is there a tool or algorithm to (topological) generalizes OSM-shapes? I would like to build a printable map in different scales. In the image below you can see the same divided road (yellow) at ...
2
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1answer
148 views

How to change the raster color range in GRASS NVIZ?

I'm trying to create a 3d map in GRASS NVIZ from a GDEM (raster) and the range of colors that show the height of the terrain are very ugly, how I can change them? For example, I would like the low ...
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1answer
87 views

Adding additional nodes to network in Grass GIS

I have created a network in Grass GIS (using v.net, nodes option). I then want to "disrupt" the network (i.e., create some road blockages) and add in nodes to the new line ends where road blockages ...
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228 views

problems with r.sun from GRASS

I´ve problems with r.sun from GRASS. I need to calculate beam radiation, reflect radiation and diffuse radiation wwith this tool. my problem is I do not understand that you have to put mandatory files ...
0
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74 views

Raster image outside Grass screen, How to get it inside from start?

HI ALL: I'm new in Grass and need some help! I have created a LOCATION based on the coordinate system in which I want my data to be projected. So far I'm being able to Import & display the raster ...
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5answers
2k views

How to pansharpen LANDSAT 8 in GRASS?

Having used QGIS for quite some time for mapping, I was 'forced' to dig into GRASS as pansharpening is not directly executable in QGIS. After understanding more or less the structure, I did some ...
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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 ...
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1answer
138 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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1answer
364 views

r.basin.py GRASS addon

I have added this add on with g.extension on my grass 6.4.3RC3. But it doesnt work... this is the error I can see: Traceback (most recent call last): File "C:\Program Files (x86)\GRASS GIS ...
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2answers
218 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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1answer
222 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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0answers
340 views

How can I calculate raster cell area for upslope contributing area

I am new to spatial analysis, and urgently trying to follow this tutorial to generate a topographic wetness index for my area of interest: ...
4
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1answer
485 views

R gridding and contouring options

I want to make an interactive web mapping application, which will grid and contour user data. My plan is to implement R scripts with Shiny, but the only R package I can find to do this is gstat. And ...
0
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1answer
152 views

How to setup and use GRASS?

Previously I've asked an question and Micha gave me a helpful advice:How to find the watershed area for each point in the river network using DEM? After getting the useful DEM file, I began to setup ...
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2answers
713 views

3D Interpolation using point cloud in GRASS GIS

I've imported a set of 3D points (z,y,z) into GRASS GIS. I'm having trouble: a) visualising my dataset in 3D using nviz or the standard data viewer (I can only get a 2D plan view of my data) and, b) ...
2
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1answer
364 views

how to loop grass command in python and put variable in output file

first day Grass programming with python scripting; first prob; simple I want to reclass the same raster several times; and save the file with the value loop variable at the end ... can not get it ...
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1answer
371 views

How to estimate distance from points to line feature with v.distance?

I'm trying to use the v.distance module in GRASS 6.4.3 to estimate the distance from a series of point features (animal tracking locations) to the nearest point along a line feature (a coastline). I ...
6
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324 views

How to create a topologically correct dataset in PostGIS (with GRASS)?

I have shapefiles which I have loaded in postgis and now i am trying to use geometric function in postgis like ST_intersect and they fail because the data is not topological correct. I have tried to ...
3
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1answer
3k views

How to find the watershed area for each point in the river network using DEM?

Update#1: Thanks, Micha, I have followed your instruction and successfully use the modules in GRASS. I use r.watershed to get the basin raster and the drainage line: and I use r.water.outlet to get ...
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162 views

Grass won't import shapefiles

I have a problem involving the import vector data command, specifically importing shape files. I installed QGIS on a pc at work and there I could import shape files into GRASS GIS 6.4.3RC2 (which is ...