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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1answer
333 views

Compilation of GRASS 6.4.trunk on Win7

you may have seen my other posts, at the point now where I am trying to use the landsat plugins in a lower version of GRASS. Markus N noted that the 6.4.2 might be better, since that is not out yet I ...
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vote
1answer
542 views

Win7 GRASS 7 & i.landsat.toar

Hello has anyone got experience running i.landsat.toar ? The output files I get are empty, the command takes but a moment to complete. However when run in verbose mode all the calculations are done, ...
1
vote
2answers
413 views

GDAL-GRASS building fails

When I run ./configure --with-grass=/usr/local/grass-6.5.svn/ I get the following errors: .......... checking for gdal-config... /usr/bin/gdal-config using /usr/lib/gdalplugins as GDAL shared library ...
3
votes
1answer
203 views

SVN Version of GRASS and QGIS

I have GRASS6.5 SVN installed and wanted to go for SVN installation of Quantum GIS in Ubuntu 11.04. So as instructed in QGIS Wiki, I added the qgis repository to my sources.list file. Now I am able to ...
6
votes
3answers
417 views

Grass v.rast.stats returning null values

I have a vector layer (polygon) and a raster layer. The raster layer holds values for height above bald earth in a field called "value". I'd like the vector layer to inherit either the mean or the ...
3
votes
2answers
186 views

Is there a shortcut in GRASS for importing vector files?

Is there a keyboard or command shortcut in GRASS for importing vector files? If you know link where I can find maybe whole list of shortcuts for GRASS, that would be awesome. Thank you.
6
votes
2answers
704 views

What's a good toolchain to reproject some PNGs in plate carre to UTM?

I have some PNGs produced from Canadian DEM data. They're 1201px by 1201px heightmaps. Each one represents one quarter of a degree latitude and one quarter of a degree longitude. But I want to work ...
4
votes
4answers
1k views

Where can I find a tutorial for installing an addon to GRASS GIS that a six-year-old could understand?

I want to use the r.stream.distance addon in GRASS GIS 6.4 on ubuntu 10.04 (64 bit). I've installed grass from the repositories and that works fine but I can't seem to figure out how to install this ...
4
votes
1answer
809 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 ...
11
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5answers
1k views

Large shapefile to raster

I have a large shapefile (1 gb) and need to rasterise it. I have tried the following already. 1.) Import it into GRASS using v.in.ogr this failed with the error message: ERROR: G_realloc: unable to ...
8
votes
1answer
608 views

Kriging on GRASS+R

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). ...
3
votes
3answers
695 views

How do I draw on a vector map in GRASS?

I have a vector map that has two lines. I want to have the two connected. Is there a way for me to draw a line to connect the two? I am using GRASS gis by the way. The two lines that I want to connect ...
3
votes
3answers
422 views

Can a raster map in GRASS be saved in JPEG/BMP format?

I'm trying to save a raster map in GRASS in jpeg/bmp format without using the GUI for d.out.file/d.save. Is there a script to do it? I tried r.out.gdal but it produced a map that is black and white.
14
votes
2answers
2k views

Is there a way to automate the preprocessing of LANDSAT data?

I'm currently enrolled in a remotesensing course, using LANDSAT data. Part of my course is about standardizing the scenes based on radiance values. I assume that because this is such a tedious task, ...
5
votes
2answers
720 views

Raster to Vector: Displaying classes in Vector Layer - GRASS GIS

I use Maximum Likelihood classification to classify Landsat image into two landuse classes - one of my interest and rest including all others. Inorder to assess the accuracy I export it in vector ...
2
votes
1answer
188 views

Error in using/installing v.digit: GRASS GIS

When I wanted to edit a shapefile in GRASS I got this message: Unable to start wxGUI vector digitizer. Do you want to start TCL/TK digitizer (v.digit) instead? Details: No module named ...
1
vote
1answer
372 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 ...
0
votes
1answer
370 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?
4
votes
5answers
619 views

How to save a raster and vector into a single PNG file in GRASS?

I am trying to save a raster and vector into a PNG file. The vector is overlayed on top of the raster map. I was only able to save the raster file into a png using r.out.png but without the vector.
3
votes
1answer
500 views

spgrass6 and GIS_LOCK

I would like to thank's everyone first, i learn a lot here (gis.stackexchange) about GIS. I have one question about the use of GRASS within R session, i'm able to do some basic task, but i have one ...
5
votes
2answers
2k views

How to return raster values based on polygon (shapefile) boundaries in QGIS?

How to return raster values based on polygon (shapefile) boundaries in QGIS? Is this an elementary question, because I am finding it hard....... Ideally I would like a neat workflow as I am likely to ...
0
votes
1answer
119 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 ...
0
votes
1answer
399 views

How to transform a DEM to a cartesian coordinate system?

I am using the script r.inund.fluv. I run the script with all the required parameters and it produced a lot or errors. I emailed the author of the script and he said that "I think you are not ...
6
votes
1answer
643 views

How to modify the colors of a raster map to use only one color in varying shades?

I have a raster map in GRASS containing elevation values. I want to display the elevation values in only one color (specificaly blue) but in varying shades of blue. I tried the options in r.colors, ...
4
votes
1answer
668 views

How to extract features from a vector layer?

I have a vector file containing the river lines of an area. I want to extract a specific water line from the vector. I used: v.db.select but it only displayed: ...
4
votes
2answers
673 views

Altitude Above channel in GRASS 6.4

i'm fairly new to the GIS world and GRASS (come from econometric background), i would like to do some species distribution modeling using R and GRASS. So i started to read the book of Tomislav Hengl ...
7
votes
1answer
429 views

Saving Command History/Outputs to a file - GRASS

Is there any way to save the commands typed and the outputs obtained in terminal under GRASS GIS to a text file? I have read that GRASS saves history for each mapset but I have no much idea about how ...
3
votes
1answer
427 views

Slope, aspect and beam in R.Sun (GRASS)

I'm starting to mess about with the solar radiation packages of GRASS and ArcGIS and have become rather stuck on the GRASS side of matters. I have a DSM area, and that is feeding into GRASS well ...
4
votes
1answer
121 views

Export Region definitions - GRASS GIS

I use two different Landsat datasets in different computers. But the region settings I work is the same. Is it possible to export the region settings in the form of a file in GRASS?
3
votes
1answer
273 views

Problem in r.resample

When I run r.resample to crop a map by using a vector and a mask, the resulting map has the same shape as the vector that I used but does not replicate (exactly) the portion of the raster map that I ...
4
votes
2answers
265 views

How to select a subset of separate bands in GRASS GIS?

As you know landsat data has separate files for different bands. Creating a subset is a wise option to work on region of our interest. Therefore, I used this method to subset my image - d.zoom || ...
3
votes
2answers
888 views

How to delete a base map in GRASS?

I'm trying to delete a map that I used as a mask before, but I cannot delete it using g.remove. It displays this: g.remove rast=raster_Mnorzagaray@PERMANENT [raster_Mnorzagaray@PERMANENT@PERMANENT] ...
1
vote
1answer
603 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: ...
1
vote
2answers
378 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 ...
7
votes
1answer
999 views

GRASS - Will r.to.vect work on this scanned map?

Total GRASS noob here. I have several very large hand contoured maps to digitize, and this thread intrigues me. In the past I have spent hours upon hours digitizing these maps and revisions in ArcMap. ...
4
votes
2answers
3k views

How to install add-ons in GRASS?

How do I install the r.inund.fluv script in GRASS? https://svn.osgeo.org/grass/grass-addons/grass6/raster/r.inund.fluv/
2
votes
1answer
652 views

How to use GRASS with HEC-RAS?

I am trying to use HEC-RAS for the flood modelling of my flood simulation. How do I use the text file output of HEC-RAS with the GRASS script r.inund.fluv?
1
vote
1answer
230 views

The resulting maps from a r.mapcalc script is not computed properly

This post is a continuation of my other post Why is my controlling shell script not working?. I created another post because this contains a separate issue that I encountered with the same scripts of ...
1
vote
3answers
421 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 ...
0
votes
1answer
283 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 ...
3
votes
1answer
835 views

Is there a way of cutting a raster map that is displayed in the GRASS GIS Map Display?

I have a raster map that I generated from cropping/masking from a bigger raster map. It produced a map with only a portion of not null values. I only want to have a map that is zoomed in to the ...
8
votes
3answers
2k views

R: Download a large DEM, change projection, and adjust to smaller scale

This is a process that takes just a few seconds in GIS software. My attempt to do it in R uses a large amount of memory then fails. Is there something wrong in my code, or is this just something R ...
1
vote
1answer
405 views

Grass GUI integration

Is it possible to embed the GRASS map display to a C# application? I know that a PNG image can suffice but to make the application more interactive it could perhaps be integrated. In essence I would ...
1
vote
1answer
341 views

Shell script commands

I have this shell script: #!/bin/sh r.mapcalc water = 120 d.rast water i=1 while [ $i != 100 ] do n=1 while [ $n != 10 ] do r.mapcalc < water.mapcalc d.rast ...
1
vote
1answer
244 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 ...
1
vote
1answer
379 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 ...
12
votes
1answer
1k views

How do you use GRASS's v.kernel?

I am flummoxed on how to use GRASS's v.kernel. I have a vector layer of around 2.5 million points. I want to make a heat map using v.kernel to show concentrations, since I have variable instances ...
2
votes
2answers
150 views

Can the arrows produced by the d.rast.arrow GRASS script be queried or stored?

I have created a map with the flow directions using the d.rast.arrow. Can i query on the map to know where the direction of the arrows are? I am going to use the arrow directions in an algorithm. Or, ...
4
votes
2answers
1k views

How to delete a map from the GRASS interface?

I want to delete a map that I generated from GRASS. I tried removing a map from the "Map Layers for each display" tab in the GRASS GIS Layer Manager, but it only removed the map from the list and not ...
3
votes
2answers
192 views

How to make the arrows in d.rast.arrow GRASS script visible?

I'm trying to create a Flow or directional raster map (with arrows) from an SRTM elevation map that I downloaded from CGIAR. I already created an aspectMap to be used for the d.rast.arrow. I used ...