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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Problems installing r.roughness

I am trying to install r.roughness in GRASS 6.4.3. It starts compiling but at the end I get this error: ERROR: Module did not install properly I cannot identify the problem. Can somebody that has ...
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11 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 ...
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34 views

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

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 ...
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31 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 ...
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27 views

Connecting Grass with R

I need help to connect R with Grass. In RStudio when I send the line: loc <- initGRASS("C:/Program Files/R/R-3.1.0/bin/i386", home=tempdir(), override=TRUE) It says: Error in ...
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52 views

Select polygons that do not intersect any other polygon using QGIS, GRASS, SAGA or R

I would like to select the polygons of the layer below that do not intersect with any other polygon (within the same layer). How can I do this using QGIS, GRASS, SAGA or R?
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16 views

Create a common scale for different raster layers in GRASS, SAGA or QGIS

I have a number of layers that represent the temperature variability of the water in a lake. They have been generated trough interpolation and have different values as they represent temperatures ...
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36 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 ...
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46 views

Can QGIS alone can be used without installing grass?

can QGIS alone can be used without installing grass? i want to use functions of grass and i am not interested to create mapset and all. just with raster and vector files, i want to study temporal ...
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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 ...
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12 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 ...
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1answer
34 views

How to mask the images in GRASS

I have MODIS NDVI images, which needs to be masked with VI_Quality. I am using GRASS software and executing GRASS commands using shell scripts. I need to perform raster calculation (multiplication) ...
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17 views

GRASS module g.mremove returns irrational outputs

I want to use g.mremove to remove multiple files in my mapset, import os import sys sys.path.append(os.path.join(os.environ['GISBASE'], 'etc', 'python')) import grass.script as g import ...
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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 ...
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28 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 ...
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16 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 ...
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2answers
60 views

How to create a time series with a NetCDF raster from Ensembles E-OBS using GDAL, R, GRASS GIS or SAGA GIS

I downloaded a NetCDF file that contains daily precipitation values from 1-1-1950 to 30-6-2013. The raster has 23191 bands. http://eca.knmi.nl/download/ensembles/download.php My goal is to analyze ...
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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 ...
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78 views

How to number points along a line consecutively

I have a line and along this line I have different points which are max. 20m away from that line. Now I would like to number the points along the line, like shown in the grafic. Any suggestions how to ...
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107 views

Why my python script of r.watershed has no output?

I type those code in pyscripter, import os import sys #set up GRASS environment variables sys.path.append(os.path.join(os.environ['GISBASE'], 'etc', 'python')) import grass.script as g import ...
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25 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: ...
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26 views

Better ways to check if GRASS r.water.outlet works out fine output

I use my python script to call GRASS module r.water.outlet from outside, and here's my script(I perform this script in pyscripter): import os import sys #set up GRASS environment variables ...
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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 ...
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153 views

Convert 800 .hdf4 files to Tiff using GRASS/QGIS/SAGA/GDAL/R

I've have MODIS ndvi data (MODIS_Grid_16 days NDVI) from the iberian peninsula, from February of 2000 to August of 2012 (really big data). How do I batch convert about 800 .hdf MODIS files to .tif ? ...
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32 views

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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172 views

How to process MODIS ndvi data using QGIS/GRASS/R?

I have MODIS ndvi data (MODIS_Grid_16 days NDVI) from the iberian peninsula (3 tiles), from February of 2000 to August of 2012 (really big data). I want to know how to deal with this kind of files. My ...
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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 ...
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33 views

Matching two point clouds without loss (nearest neighbor, but more complicated)

I have two point clouds, one with demographic and one with electoral data. Points in both clouds represent the same empirical entity (say, a village, or an urban neighbourhood), but are not in the ...
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113 views

How to increase resolution of 3D image in GRASS NVIZ

I am trying to make 3D visualization of terrain data and orthophoto using GRASS NVIZ via QGIS. I have been able to import both the DTM and the orthophoto in NVIZ window and successfully draped the ...
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134 views

Problem with python script to control GRASS GIS from outside - How to import grass.script under Win 8.1?

I am working with GRASS 6.4.3 and python 2.7.6 under WIN 8.1. I am a novice with computer science and coding, and I have seen many posts including those:Is it possible to use GRASS GIS in Python ...
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39 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 ...
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50 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.
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1answer
36 views

Can one batch-automate the creation of QGIS heatmaps?

I have 4k point shapefiles, from which I would like to generate heatmap TIFFs using the QGIS heatmap plugin (or a functional equivalent featuring triweigth, radius and cell size selection). Is there ...
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2answers
53 views

How to do the loop when using GRASS module r.water.outlet?

I have seen this post:Watershed Analysis with GRASS, and I have a .txt file which contains coordinates of many points, and I want to use r.water.outlet to get basin area of each point. I type the ...
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15 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 ...
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54 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: ...
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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 ?
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61 views

Snap points to line and calculate chainage using Open source GIS

I have a line layer (representing a pipeline) and a points layer (representing valves) and I would like to calculate the chainage of the valves along the pipeline. I assume that I would first need ...
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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 ...
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1answer
55 views

95 percent volume contour

I generated, from point data, a kernel density map using GRASS, and I would like to identify the 95% volume contour in it. Is it possible in GRASS? Thank you
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22 views

Is there any GRASS command to measure the distance between a point in rastermap and another in vector map?

I have a question about WinGRASS 6.4.3. Is there any GRASS script command to measure the distance between a point in rastermap and another in vector map? I have a raster map and a vector map. Raster ...
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121 views

Creating contours for specific elevations

Input data: 1. an SRTM raster. 2. Point file of peaks. -Attributes contain ID, x, y, z and the elevation at which the peak is completely isolated from a neighboring peak. The output I want is a ...
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2answers
60 views

How to handle multiple space separator in Grass?

I try to load a Lidar point cloud in .xyz format to Grass (in QGIS 2.0.1). I tried to input the following options to the 'separator' field: tab, 'tab', '\t'. Just for the unlikely case that it ...
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23 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 ...
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1answer
101 views

Combining Geological Grids

I have a situation where I have 3 Geological grids, each showing a different horizon + the Seabed Grid. I need to extrude between these grids in order to make the 3D polygon for the geological ...
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2answers
46 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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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 ...
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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 ...
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28 views

“System not initialized. Programmer forgot to call G_gisinit().” message when loading table into GRASS via QGis

I am trying to load a CSV table into Grass with v.in.asciifrom the interface of Qgis 2.0.1 on Windows XP. As the progress bar indicated 74% of the data already loaded, I got the message "System not ...
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2answers
56 views

GRASS v.generalize method=douglas not working as expected

I'm frustrated with v.generalize trying to simplify polygons. Those polygons stem from ArcGIS's raster to vector function (imported into GRASS from Shapefile), so they are pretty zigzag like this: ...