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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Difference between python IDLE and eclipse on accessing GRASS

I have seen these posts:GRASS and Python, Using Eclipse to develop GRASS Python programs. I used to use python IDLE to control GRASS, but I can't make python and GRASS connected, as I described in ...
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70 views

Interpolation using GRASS plugin in QGIS

I have been using the IDW interpolation tool through GRASS plugin in QGIS and the interpolation output I am getting is for the entire mapset region. My question is: Is there a possibiltity that we ...
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88 views

v.edit break: how to loop through XY coordinates on using GRASS on Windows 7

Trying to follow the suggestions on this thread: splitting a lines layer using points However, how to do so in a windows environment using the GRASS command console is beyond me, so I'm attempting ...
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102 views

d.rast problem in GRASS command line

Update#1: @gene, thank you for your reply and I type d.mon in command line, getting a popout GUI look like this: I choose the top three flags(-l, -L, -p), and I got this: And I don't know what to ...
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68 views

g.list problem in GRASS command line

I am using GRASS 6.4.3 (installed with osGeo4w), and I have this question: As I type g.list, a function window will pop out, and all functions and results are fine. But when I type g.list rast, I got ...
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10 views

GRASS Add Vector Point

I need to do a viewshed analysis using GRASS. I've got the DEMs loaded; and I simply want to input several (2-4) points (like 41.12345N, 122.34567W from GPS). What is the simplest, most ...
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37 views

Debug/Improve Performance of GRASS v.in.ogr

I'm trying to import shapefiles (in this case, OpenStreetMap data) into GRASS (grass70-svn) using v.in.ogr; and it is painfully, brutally slow. At first I thought this was because I was using the ...
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136 views

The same error message shows up while running GRASS command

I'm using GRASS 6.4.3(installed with OSGeo4W) under Windows 8.1 x64. When I type commands in the command console below, I often face these problems: type command which has "space", like:g.list ...
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700 views

How to use GRASS module to delineate watershed area?

Update#1:I changed to work under qgis 1.8, I only input the DEM file and run the r.watershed module, and I got this: I have a DEM file of one specified region, and I take the following steps to ...
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158 views

GRASS algorithm r.los does not produce raster

After running the r.los algorithm through QGIS 2.0, I'm getting a 'Problem loading output layers' box which gives the following message: Oooops! The following output layers could not be open Output ...
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77 views

Which Landsat version is appropriate to imply a supervised classification with GRASS GIS?

I need to imply a supervised classification with GRASS GIS to find build-up areas. I want to avoid Landsat 7 images due to SLC problem. Can I use images of Landsat 8 or it's better to use images ...
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140 views

How to define correctly the Grass region in Qgis

I know that my question could be pretty basic for some of you. I am trying to learn GRASS. I have some raster layers and a vector file in EPSG 32614. Using the grass plugin I defined a new map set, ...
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106 views

Grass GIS 6.4.3, How to create a .PTS file

I'm trying to export a raster map in order to use it in the Flo-2d program. This program needs a .pts DTM file, do you know how I can create it? Alternatively, I can use a XYZ file looking like this ...
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141 views

How to perform GRASS v.rast.stats via QGIS

I have been using qgis for the last few months. I got interested in using GRASS tools through QGIS. I wanted to compute zonal statistics for a raster surface for a given polygon layer. I loaded the ...
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109 views

Removing Image Stripes / Scan Line errors

I have some seabed bathymetry data derived from seismic reflection profiles in a 2.5D dataset (closely spaced lines). The data was gridded by another worker in SMT Kingdom suite; I'm not familiar ...
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73 views

How do I install mdenoise?

How do I install mdenoise in GRASS 6.4.3? I've already successfully installed r.denoise, and have downloaded mdenoise from wget http://www.cs.cf.ac.uk/meshfiltering/index_files/Doc/mdsource.zip. How ...
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61 views

v.what.rast trouble in GRASS GIS 6.4.2

I'm facing a problem using the v.what.rast comand. I'm trying to update the vector "canali" which represents some streams, with the slope value for every single point of the lines. The slope values ...
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99 views

create POV-Ray image from DEM-file in grass

I am working on r.out.pov Tool of grass 6.4 creating a POV-ray(beautiful 3D) image from an elevation raster. You can see this link for more information about 3D analysis of GRASS. r.out.pov manual ...
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255 views

Basic raster map questions

My bigger problem is to convert a raster map to polygons. I've found some questions that give info and I'm trying to use GRASS GIS as part of that. However, I'm having some basic problems and I can't ...
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95 views

Does r.in.gdal -o reproject the imported raster data to the location projection?

Does r.in.gdal -o actually reproject the imported raster data to the location projection, or do I need to call gdalwarp to reproject prior to importing?
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83 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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44 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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414 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 ...
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65 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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75 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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92 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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98 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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71 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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223 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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128 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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170 views

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

anyone, 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 ...
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143 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 ...
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33 views

GRASS GIS: red square around node topology information?

I've been using GRASS since 2005, but I cannot find an explanation to the square boxes that appear around the nodes of a lines layers, when I display topological informations on the map. I thought ...
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171 views

Sextante grass folder incorrect?

What is the correct grass folder in Sextante? I alway get this message: The specified GRASS folder does not contain a valid set of GRASS modules. Please, go to the SEXTANTE settings dialog, and ...
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498 views

Grass 7 / ArcGIS 9.3 - tiff to raster

Again a Grass 7 question. I have the output of a modelling run as matlab file, which I can export as tiff and load as geotiff. OK - now can I extract the data/convert this tiff into a raster proper? ...
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265 views

qgis plugin: “WindowsError: [Error 6] The handle is invalid”

OS: Windows 7 64bit GIS: QGIS 1.8 (qgis.org/downloads/QGIS-OSGeo4W-1.8.0-2-Setup.exe) path variable: GISBASE=C:\Program Files (x86)\Quantum GIS Lisboa\apps\grass\grass-6.4.3RC2 ...
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35 views

Why is this GRASS script (from GRASS WiKi) causing an error?

I'm trying to run a script from the GRASS WiKi to create a simple map using ps.map. I'm confused because it's generating an error that the output was not set, when it appears to me that it is set at ...
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220 views

Error from ps.map in GRASS. How to fix?

I'm trying to learn how to use ps.map in GRASS. I thought that running it in interactive mode from the command line would be a good place to start, but I'm getting the following error: > ps.map ...
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76 views

How to align directions of connected lines?

I have a vector line made of different pieces of lines with different directions. I merged the lines to one. But this merged line still have different direction in its "invisible" parts. I want to ...
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374 views

How do you use 'reclass' in GRASS?

It could be user error, but for some reason, the reclass tool is just hanging and hanging... QGIS 1.8 Compiled against GDAL/OGR 1.9.2 Ubuntu 12.04.1 Running the tool from the Sextante toolbox Input ...
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61 views

GRASS: Loss of data using v.net

I'm trying to build a network in GRASS in order to find the shortest path from any settlement out of 1120 (points), to one waste treatment facility out of 27 (points). I plan to use v.net.distance ...
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258 views

How do I repair NVIZ error: 'Can't find a usable init.tcl'?

How do I repair the following problem: The error occurred while I was trying to run NVIZ in the GRASS environment in QGIS. NVIZ however runs perfectly in GRASS. On checking the directories ...
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157 views

How to apply v.transform on a set of vector layers (GRASS 6.4)?

I have 64 vector layers, all of them must be warped using the v.transform module; the pointsfile is the same for all vectors. How can I apply the transformation recursively to all layers? I'm not ...
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350 views

GRASS and QGIS- “ not recognized…format” but it worked before

Prologue: I used my Ubuntu file viewing GUI to move data files around and "clean house" a bit. I started a new GRASS session and tried to add NED elevation rasters which I have successfully added ...
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46 views

Does 'r.patch' act only on “loaded” rasters?

Can I run the GRASS command 'r.patch' on raster files which are not "loaded" into the current GRASS session? That is, rasters which are simply in my folder but not in a GRASS location & mapset? ...
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131 views

GRASS importing same-name rasters fails

I have NED elevation data in 3 rasters. (That's how it downloaded from USGS NED page.) The files are named "61471006", "61471006_2", and "61471006_3". I succeeded in using the GRASS GUI and menu ...
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352 views

How to convert .ps to .png in a ps.map script?

I already managed to create a .ps file. How do I convert it to .png using a GRASS script?
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113 views

d.legend script is not working

I'm using the d.legend script in grass but it is not working. I can only show/hide the legend using the 'add legend' option in the Map Display window in GRASS. I need to make d.legend script to work ...
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252 views

How to export a png file from a raster file? r.out.png has an error

I used r.out.png to export a png file, but it produced this error: (Sun Feb 27 00:26:32 2011) r.out.png input=raster_bulacanElevation ...
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120 views

How to create a new table for a vector file?

I will use v.db.connect but i want to use a new table, and not an existing table to connect it to. What is the GRASS script for it? Thanks!