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.

learn more… | top users | synonyms

0
votes
1answer
121 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 ...
0
votes
1answer
337 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?
0
votes
1answer
108 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
230 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 ...
0
votes
1answer
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!
0
votes
0answers
8 views

QGIS 2.2 freezes when I select a Grass command via Processing toolbox

I'm on Ubuntu 13.10, and I have never been able to get the Grass plugin to work in QGIS 2.2 via the Processing toolbox. As soon as I select any Grass command, QGIS locks up, no menu appears. I then ...
0
votes
0answers
31 views

Writing a script for accessing QGIS tools for use in HTML WebPage [on hold]

My objective is to write a script which uses QGIS GRASS Plugin tools and generates an IDW Interpolation Output and passes the file path as a parameter, which can be used in an OpenLayers API ...
0
votes
1answer
23 views

GRASS 6.4.3 installed with QGIS not working

I'm new to QGIS and GRASS. I'm trying to do an image classification and it seems that the method I need is not within the GRASS toolbox in the QGIS . So I decided to use the standalone GRASS version ...
0
votes
2answers
32 views

How to remove small areas without reducing borders

I'm having a problem where I am overlaying two maps to create a new kind of map with the data conjoined. In general this is good, but I need to remove the smaller areas from it. For the interior ...
0
votes
1answer
31 views

Producing gradients between shapefiles and using original boundarys as isoclines (lines)

to produce a bathmertical map of a river bed I draw shapefiles showing the different depths based on satellite images taken during different tidal levels (deepest, 2nd deepest, 3rd deepest, shore ...
0
votes
2answers
10 views

Adding time stamps to animation slides with OSS tools

I would like to create an animation with time lapse values printed on the PNG file. For this purpose I have created in QGIS a vector layer that stores timestamp and temperature value pairs for various ...
0
votes
1answer
46 views

GRASS module g.copy returns irrational outputs

I took this as reference, Moving raster to different mapset GRASS GIS, and I use pyscripter to use GRASS module g.copy from outside, import os import sys #set up GRASS environment variables ...
0
votes
0answers
27 views

GRASS module g.mapset can't create new mapsets from outside

I use pyscripter to control GRASS from outside. I want to create a new mapset named water. Here's my script to generate new mapset, import os import sys #set up GRASS environment variables ...
0
votes
1answer
15 views

vector file is used by two mapsets at a time in grass gis

i want to study about vector processing.if a vector file is used by two mapsets at a time, which one will be saved first and why.if a team want to work on the same set of shape files, what is the ...
0
votes
0answers
7 views

Printing a label from a point layer attribute on a raster layer (GRASS)

I am interpolating with boundaries using v.surf.idc in GRASS. It works wonderfully and I fully recommend it. I am creating an animation and I use v.surf.idc to generate sequential interpolated raster ...
0
votes
0answers
23 views

No data appears when using gdal_calc.py but source had data values

I'm in the process of calculating topographic exposure using a mix of GDAL, grass, R and python in Windows. I need to process a very large tiff file using the following calculation: ...
0
votes
0answers
8 views

Grass - How to add average elevation of line features to a new colum

I have a shape file with 3-D (contour) lines. The vertices of any single line may have tiny differences in the z-value (elevation). Ho can I create a new column "ele" and fill it with the average ...
0
votes
0answers
68 views

Defining the boundary of a catchment area

I digitized contour lines from topographic maps and created a DEM. With the DEM, I estimated the boundary of a catchment area. Estimated positional accuracy of topographic maps is RMSE = 65 m, with a ...
0
votes
1answer
37 views

RuntimeError from r.viewshed in graphic modeler

after using r.los in QGIS want to switch to r.viewshed in GRASS GIS 7. i need to do a lot of viewshed analysis form given points of a vectorlayer. if i try to add r.viewshed to the graphic modeler i ...
0
votes
1answer
47 views

QGIS-Processing GRASS-tools don't work

When I try to use the processing grass tools like r.series I always get the following messege. I deinstalled QGis and reinstalled the program totally fresh without success.
0
votes
0answers
14 views

GRASS GIS - v.select- ERROR: bad allocation -

I'm quite new to Grass GIS. I have two vector maps, one of a grid (each grid cell is a polygon) and one of a much larger polygon. I've been trying to select the grid cells that lie completely within ...
0
votes
0answers
52 views

QGIS cannot open output layers

I have problem with QGIS 2.0.1. Everytime I run tool from SAGA or GRASS, I get exactly the same error, for example: Oooops! The following output layers could not be open Channel Network: ...
0
votes
0answers
83 views

Grass 7 voronoi vertices error

I tried the voronoi diagram for area function and got the message "ERROR: Found 0 vertices" - any suggestion ?
0
votes
0answers
27 views

r.shaded.relief plugin on a DEM layer

I loaded a raster digital elevation map from the DEM explorer website. I defined the projection and created a mapset. I then loaded the raster file into GRASS with the r.in.gdal plugin to create a DEM ...
0
votes
0answers
22 views

How to access nodes of a line network by using programming?

I have been given a manually digitized drainage (stream) network that needs ordering based on some rules (purely based on that single vector layer). I have built and cleaned the topology (removed ...
0
votes
0answers
18 views

problems using GRASS v.net and v.net.allpairs

I am using GRASS 6.4.3, and I am trying to use it to do network analysis. I have a line shapefile and a point shapefile, and here is my code(I take v.net.allpairs as my reference): v.net tc_bf25 ...
0
votes
0answers
9 views

problems using v.net.allpairs

I am using GRASS 6.4.3, and I am trying v.net.allpairs to do network analysis. I have a line shapefile and a point shapefile, and after I use v.net.allpairs, I type the command d.vect network, and I ...
0
votes
0answers
35 views

Adding a GRASS module manually in QGIS (Mac OS X)?

I am trying to add a precompiled non-standard GRASS module to QGIS 2.0.1 (MAC OS 10.9.1, using the binaries by Kyngchaos). Adapting the instructions here ...
0
votes
0answers
20 views

How to install grass addons when offline?

Can anyone tell me how can I install GRASS (v.7) addons on a windows PC when offline? I manually downloaded the files from http://svn.osgeo.org/grass/grass-addons/grass7/ and copied: - the .py file ...
0
votes
0answers
65 views

Can't launch GRASS GIS 6.4.3 GUI on windows 8.1

As title, I downloaded GRASS GIS from this website: GRASS GIS - Home, and I choose winGRASS 6.4.3 standalone installer to download. After I installed, I click on its icon: I can't launch it even ...
0
votes
0answers
93 views

In GRASS in QGIS, what do I do if “NVIZ module not found”?

I was a on a Windows system using GRASS in QGIS when the error below occurred. NVIZ module not found I wonder how I can solve this problem?
0
votes
1answer
73 views

Cleaning shapefiles with islands in GRASS GIS

This may be very simple, but I'm new to GRASS GIS. I have a large shapefile containing global species ranges, which needs topological cleaning. I imported this into GRASS GIS 6.4.3 using v.in.ogr (a ...
0
votes
0answers
37 views

Removing multiple categories from GRASS vector feature

Pardon my lingo if this is not entirely correct - I am a software developer, not a GIS person. We're working a project that uses v.overlay to merge a map of slopes with a map of soil tests to produce ...
0
votes
0answers
15 views

How to obtain stream segments from complemented image(raster data)?

I have raster data in tiff format, i want to extract stream segments from the complement of original raster data. I am able to extract stream segments from original raster data, but not able to ...
0
votes
1answer
53 views

Error using “r.los” in QGIS

I am not a "computer person". So -- I don't know what this error message means. I found this question and answer for this same problem, but the solution did not work for me, dammit. GRASS algorithm ...
0
votes
1answer
44 views

Analysing a network distance to two or more points using GRASS or QGIS

I am doing a piece of analysis work looking at distances along a network in GRASS. Most of the analysis involves finding which parts of the network are within 600m of a series of points. GRASS does ...
0
votes
0answers
25 views

OSX: Installing GRASS addons in qGIS?

I would like to install r.stream.basins in GRASS through qGIS (2.0.1-Dufour). I tried using g.extension ext=r.stream.basins and got the error "the 'make' program is required. Please install first". ...
0
votes
0answers
16 views

grass: walking along vector line

I have a line vector which I converted into points with v.to.points. I need to get the coordinates of each point AS I WOULD WALK ON THE LINE. v.to.ascii appears to just use some other order, but I ...
0
votes
0answers
22 views

alignment of shapefiles in GRASS

I have two shapefiles below. One is in the state plane projection, and the other is not projected. In ArcMap the shapefiles line up perfectly. When I import them to my mapset (using the override ...
0
votes
0answers
74 views

Problems using GRASS GUI (d.rast and r.watershed)

Update#2: I tried the command in the function list above instead in command console, and I got this in command output: and it displayed nothing, showing the same error message in the command ...
0
votes
1answer
21 views

grass on ubuntu cannot import globalvar

I installed GRASS GIS 6.4.3 on Ubuntu Precise 12.04 by sudo apt-get install grass grass-doc, as recommended by the Wiki. It runs with the wxpython GUI, but when I use any command (like r.in.gdal or ...
0
votes
1answer
28 views

How to use the Cartographic Composer of GRASS 6.4.3?

Following on from my previous question (which was, again, how to use the Cartographic Composer)... I've got a GIS in GRASS. I need to print various bits of it. Problem is, it needs images on it ...
0
votes
0answers
22 views

gdalbuildvrt ------— Problems with binary rasters used by grass

r.in.gdal is used for importing tif images in grass environment and they were changed to binary by default. I am trying to make a stack from them but unfortunately grass does not see my rasters ...
0
votes
1answer
63 views

Importing SRTM Data into Grass

I am having issues importing an SRTM HGT file into Grass. I first made a new location as the instructions from this Grass Newsletter Tutorial states. I then went to the download site and downloaded ...
0
votes
1answer
27 views

How to import r.in.gdal from WCS (only region extent)

Can I import WCS-Data only for the current region by r.in.gdal? I tried to import raster data from my WCS into GRASS GIS, using r.in.gdal as proposed in ...
0
votes
0answers
16 views

i.atcorr empty raster

I am recent GRASS GIS user who is trying to run the i.atcorr module to atmospherically correct a Landsat ETM+ image in GRASS 7 (on MacBook Pro, Mavericks OSX). This image has been already converted to ...
0
votes
0answers
33 views

tif file creation

Does anyone have any idea how to get around this problem? I've been looking for a solution to no avail. I'm trying to convert a shp file to a grid, and the tif is hanging up. Output raster layer: ...
0
votes
0answers
29 views

Unable to set pg as default backend with osgeo4w GRASS

I am trying to set PostgreSQL as default backend for GRASS, but cannot manage to get it right. Working with GRASS 6.4.3 print g.run_command('db.connect', driver='pg', flags = 'c', ...
0
votes
0answers
73 views

Calculating vector statistics in GRASS

I have a points layer, each of points have an year attribute and I want to count how many points in each year. I use GRASS-GIS and its v.univar function: v.univar -e map=mod14_hmao column=year ...
0
votes
0answers
61 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. ...