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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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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163 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
279 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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803 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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107 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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524 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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82 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 ...
4
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2answers
255 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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87 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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2answers
453 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
119 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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245 views

Combining Geological Grids and extruding between them?

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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192 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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53 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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3answers
480 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: ...
3
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2answers
2k views

QGIS GISBASE specify location

I am just a beginner at this QGIS and GRASS and I am using this QGIS 2.0.1 Dufour which throws a error at the startup that "QGIS couldn't find your GRASS installation. Would you like to ...
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150 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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458 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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1answer
132 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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200 views

libfreetype-6.dll lost when using GRASS command line

Update#1: Following the instruction of Sorin Călinică, I have installed libfreetype-6.dll using the OSGeo4W Network Installer, and the command d.rast can launch successfully. I am using GRASS ...
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0answers
31 views

Multiply vector categories

I have imported a Vector map into GRASS GIS. There are some problems with the topology and some polygon areas overlap. I used v.clean to break overlapping polygons and now I have multiple polygons ...
2
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1answer
239 views

How to iterate GRASS region definition?

I am using GRASS r.skyview command (v.7, Windows) to determine "urban canyon effect" on pollution due to the presence of buildings. The command nicely works, unfortunately I need to process a very ...
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2answers
644 views

How to import R-generated .gri/.grd raster files in GRASS?

I received data in .grd + .gri format, where the first one is a small text file and the second one (having the same name) is a binary file. I am unable to open them in GRASS/QGIS. Any hint ? Missing ...
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126 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 ...
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399 views

How to make GRASS and SAGA tools capable to use in QGIS?

As my title, I installed Qgis, GRASS and GDAL by osGeo4w package, and as I finish the installation, I want to use GRASS tool, I face this problem: But I already installed GRASS and SAGA, how to make ...
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1answer
511 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 ...
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1answer
113 views

display 3D raster/vector in GRASS 7.0 from command line

I am using GRASS 7.0 on ubuntu linux 12.04 x64. I am working through some GRASS tutorials and am able to get a 3d raster to show up when I use the GUI. However, I cannot get the command line interface ...
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1answer
609 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 ...
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2answers
627 views

Creating square buffer in qgis

How can I create a buffer with square ends along a line segment in qgis? I've buffered lines using v.buffer in the GRASS plugin, but the -c option for square ends is not exposed in that interface. ...
2
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1answer
2k views

How to identify line intersection in QGIS when I have more than 2 lines?

I am trying to identify where overlaps exist between multiple shapefiles. I would use the intersect tool, but it only allows me to intersect two layers. I have over one hundred individual line ...
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1answer
194 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 ...
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15 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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90 views

header information is missing from image, after writing using opencv

I am doing complement of an image using open-cv python, while writing the image, open-cv is not writing the header information in the complemented image. my image data are in TIFF format. i am doing ...
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1answer
121 views

Is it a good idea to use GRASS Algorithms for Geoprocessing in a Server Environment?

I´m designing a web-service to run in a server environment that will do some geoprocessing actions to datasets uploaded by users and send the results back. I´m programming in Python, and so far I´ve ...
4
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2answers
609 views

Merge two rasters with no data value

I have two rasters: Raster A and B. Raster A has has only values of 0. The white area in Raster B are No Data values. I want to merge them to one raster (Raster C). So basically I want all pixels in ...
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2answers
908 views

How to split lines into equal segments with QGIS?

I'm attempting to split a curved (wiggle) line into equal length segments. Have used Grass's v.split which works to a degree but does not provide the output I'm after. v.split will extract segmented ...
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2answers
1k views

How to interpolate a point vector layer inside a boundary (polygon layer) QGIS/GRASS/SAGA?

I have a to create a heatmap of water temperatures inside a lake for which I have sample points. The map should look much like the climate maps generated by climate change models. I have the ...
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3answers
622 views

splitting a lines layer using points

I'm looking to accomplish a similar task to this thread: How to split a line at point positions? Using QGIS and the Processing and GRASS toolboxes available, I'm looking to split a vector layer ...
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1answer
101 views

Is there a tool to buffer features with more than one distance value in GRASS GIS?

I´m looking for a tool like Multiple-Ring-Buffer in ArcGIS, but for GRASS GIS to be able to buffer with different distances but only having to start the process once.
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1answer
110 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
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1answer
44 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 ...
1
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1answer
285 views

Apply r.neighbours or Neighbourhood analysis (LecoS plugin for QGIS) to 3000 rasters

I need to apply r.neighbours or Neighbourhood analysis (QGIS plugin LecoS (or equivalent) to 3000 rasters and define a neighbourhood of 5 x 5 and calculate the mean. I suppose I need to create a ...
0
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1answer
240 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 ...
2
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0answers
86 views

QGIS V. parallel command using GRASS

I cannot offset a line to a specific decimal place, (ie only whole numbers can be inputted) Am I missing something here??
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1answer
60 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 ...
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1answer
2k 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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2answers
458 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 ...
0
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1answer
67 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 ...
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118 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 ...
2
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2answers
63 views

How to produce maps with copyright imagery on it in GRASS?

I'm having some trouble with a GIS that I've got to produce. I work for a contractor and we'll have to produce maps to do the work for our client. The client has specified that if we print maps out ...