QGIS is a cross-platform GIS application licensed under the GNU General Public License.

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0
votes
1answer
745 views

Using Union on multiple shapefiles to output single result

Using QGIS 2.2 and Python, I would like to use the Union algorithm on multiple shapefiles (contained in a folder TEST) which would then produce single shapefile containing all the data. Currently ...
2
votes
2answers
467 views

How to switch to edit mode vector layers, in pyqt application based on qgis?

I do QGIS based application, I need to implement the ability to modify the geometry of vector layers in manual mode (editing nodes), how to do it?
0
votes
0answers
420 views

How to extend lines from “station line” plugin in QGIS

I'm trying to create cross sections using the station line plugin (and then import them to HEC RAS). But I can't seem to create lines longer than 99.99 meters from each side of my river line. Is this ...
2
votes
1answer
169 views

Low quality legend symbols in QGIS

The legend symbols in my QGIS map composition render very pixelated, like this: However, they render fine for actual point data. They appear this way within map composer, when printing, and when ...
0
votes
1answer
151 views

QGIS copy and paste error: “no features could be successfully pasted”

What does this error message mean, and how can you get more info on what might be the cause? "no features could be successfully pasted" (or more generally, not all of the selected items could be ...
1
vote
1answer
103 views

Why is interpolation adding too much heat

I am interpolating geo data using qgis. The data is in the form of lat,lon,count. The path of the collected data is shown as a mostly transparent line. The resulting heatmap it produces is shown. ...
0
votes
1answer
227 views

from Qgis 2.2 to Garmin Base Camp: how to get rid of the white frame?

I have geo-referenced a raster map in QGIS 2.2 (with the georeferencer plugin) and I can also create a kmz file for my garmin (Dakota20) with GarminustomMap. However the kmz file, as imported in Base ...
2
votes
1answer
254 views

How to exactly georeference in QGIS

When I georeference a raster image in QGIS, it's always a bit displaced as in the attached image (the cyan polygon is the template, the red border is the georeferenced image), although I try to set ...
3
votes
1answer
266 views

Maximize clusters of points from coordinate data

So I am definitely new to the GIS world, so bear with me if I don't know the best way to articulate my problem. That said, I am ready to learn, I would definitely welcome any direction that you all ...
1
vote
2answers
3k views

“Missing dependency.This algorithm cannot be run :-(” QGIS + GRASS Windows 7

Windows 7, OsGeo4W pack installed including QGis 2.4.0 and GRASS. I Qgis when i try to execute a GRASS geoprocessing algorithm i get this popup: "Missing dependency.This algorithm cannot be run :-( ...
3
votes
0answers
404 views

How can I label the pie charts in QGIS so the labels are written under the diagrams?

How can I label the pie charts in QGIS so the labels are written under the diagrams? My pie-charts are representing localities: such as villages, towns, cities. So, I want that their names appear ...
0
votes
0answers
457 views

Why can I not publish from -QGIS Geoserver plugin?

I am following the tutorial at http://qgis.boundlessgeo.com/static/docs/quickstart.html and I get to the step "To publish the project as it is, just select the QGIS project entry in the OpenGeo ...
1
vote
3answers
245 views

How to complete the roads output of PostGIS?

I converted the file I exported from OSM to PostGIS using osm2pgsql. I have opened the table's outputs to QGIS and I saw data are not complete compare to OSM editor view. Most of the roads are broken ...
10
votes
1answer
736 views

How to call the interpolation plugin from the python console?

I would like to call the QGIS interpolation plugin function (TIN method) (Raster->Interpolate) from python console. I can't find the corresponding function within QGIS API or within the ...
2
votes
1answer
240 views

QGIS contour plugin exception struck help

I am a fisheries biologist and I am just getting started with QGIS. I took a few GIS classes in college so my GIS knowledge is not extremely high. On to my question. I am trying to make a depth map ...
3
votes
1answer
549 views

How to open, modify and save a QGIS project with PYQGIS

I need to create a stand-alone script for opening a QGIS template project, modify a layer data source, export the Composition and finally save the modified .qgs project into a new file. So far I have ...
1
vote
0answers
78 views

PostGIS points to multipoint error

I have a table on PostgreSQL 9.2 ("POSTGIS="2.0.1 r9979" GEOS="3.3.3-CAPI-1.7.4" PROJ="Rel. 4.8.0, 6 March 2012" LIBXML="2.8.0""). This is it: CREATE TABLE nearest_point ( id_nearest_point serial ...
0
votes
0answers
1k views

PyQt resources file to display images on QGIS custom feature form

I am having issues creating a PyQt4 resources file to display images in my QGIS 2 custom feature form using Windows XP. EDIT This still gives me problems with windows 7 on 32 and 64 bit machines, so I'...
0
votes
1answer
258 views

PyQt QTableWidget for QGIS python plugin: infinite loop issue

I'm using PyQt4 and Python 2.7 to develop a plugin for QGIS 2. I have QTableWidgets used to display/compare existing information in the database with newly entered information pertaining to the same ...
2
votes
2answers
104 views

Cropping with GDALWarp in QGIS

I followed this post, the first answer, to clip a USGS Quad in order to remove the borders so that I can tile them. Basically it utilized the lat/long at the corners in a .txt file to import a ...
-1
votes
2answers
233 views

How can I project a power line net in QGIS?

I am working with power lines net using the software QGIS. I would like to know which plugins or tools do I need to be able drawing (projecting) them.
0
votes
3answers
107 views

How to set a coordinate transformation GRID

Does anyone know how to set a coordinate transformation in qgis so I can measure the distances in meters or kilometers? If anyone has a clue, would be just great. Thanks!
2
votes
1answer
968 views

Why do I get an error when I try and clip a shapefile to a shapefile using ogr2ogr?

I want to clip a shapefile to a shapefile. The input shapefile is a 1 m vector grid generated in QGIS. The tile I'm clipping to is just a simple polygon (the geometry is contained within the 1 m ...
0
votes
0answers
279 views

How to create .dem file in QGIS?

I have an elevation data in .asc file, but need to convert it to .dem file to later use in COMSOL. However, in Raster--> Analyzes-->DEM I got just error message: ERROR 1: DEM Default Setup: Importing ...
1
vote
1answer
290 views

Possible to run “Merge shapefiles to one” algorithm from Python script?

Developing a python script in QGIS 2.2, I can run algorithms from the Processing plugin fine such as those from QGIS geoalgorithms and SAGA. Can you do the same for the algorithm "Merge shapefiles to ...
1
vote
2answers
460 views

Qgis making a backgound map for topolines on Garmin

Hi I am a new user of QGIS, I would like to make a Background map with Topolines in gmap or img format. So I started off with Opendem shape files. I have sucessfully combined the tiles I want into one ...
1
vote
1answer
607 views

How to programmatically export a composition as image?

QGIS Print Composer has tool "Save As Image" and I found appropriate function in QGIS source code exportCompositionAsImage. Is it possible to get access to existing Print Composer from Python console ...
0
votes
2answers
5k views

how to generate a NDVI in QGIS [closed]

i have tried using raster calculator to generate NDVI and tried searching for but couldn't find it. is there any other way to extract NDVI and what are the procedures to generate NDVI in QGIS.
3
votes
5answers
801 views

How to place labels under a vector layer?

I want to place the labeling under a layer. In QGIS 2.2 apparently the label appears automatically at the top. Can someone help me. (see attachment) example:
3
votes
0answers
84 views

How to find the minimum number of inspection points?

I am working on a pipeline inspection project and there is a high liklihood that some inspection tool deployment/retrival station will need to be installed on the pipe network. the problem is ...
1
vote
2answers
453 views

Using the Rule-based style to calculate each grid cell from overlaps

I am using the Rule-based styling properties (QGIS 2.2) to determine the colour of grid cells for a merged shapefile. Each grid cell defined by its ID may be overlapped by several layers as defined by ...
1
vote
0answers
118 views

Command-line tool for writing a print-composer to file?

I'm looking for a command-line tool, to write a previously generated print-composer to an image-file. The following resources I already saw: Related questions (1, 2) A gist Nevertheless, all them ...
0
votes
2answers
903 views

Any clue how to read a .style (ArcGIS) file in Python, for converting into another platform-specific format? [duplicate]

The problem I am face with is that I have all my data as shapefiles but my organization works with only 1 ArcGIS license. Migrating to QGIS to prominent amount of work, I need to convert my ArcGIS ....
0
votes
0answers
75 views

Scale keeps changing in QGIS composer?

Every time I pan the map content in the QGIS composer window the scale changes. Is there a way to make it stick at specific scale?
2
votes
2answers
151 views

qgis raster style 'no data value' checkbox is ignored - what's a good workaround?

See bug report filed here: http://hub.qgis.org/issues/10236 Note the initial bug report got 'fixed' but that fix introduced this new error, so the issue was reopened a few days ago. Anyway, it ...
1
vote
1answer
64 views

How to remove ghost layer in Qgis?

I added a delimited text layer to a Qgis 2.0 project, working in Windows, but it got added wrong: It didn't appear in the list of layers on the left panel, nor did it show in the map canvas. However, ...
1
vote
0answers
177 views

How to keep all the unique columns of the shapefiles after merge?

Writing a script where the user is asked to select a directory which contains Folder_1 and Folder_2, both containing shapefiles and run various algorithms. The basic logical process of the script is: ...
1
vote
2answers
379 views

Retrieve Elevation from Color in Raster DEM

This might turn out to be a newbie question, and that would be because I'm fairly new to GIS work, but extensive online searching, asking associates with some basic GIS knowledge and hours in various ...
0
votes
1answer
711 views

Best Resampling Method for DEM reprojection in QGis

I need to reproject a DEM (aster file) in order to have the same CRS as all my other project data - I have different SHP for the same DEM's location but they have a different CRS. Which resampling ...
1
vote
2answers
95 views

Coordinate Reference System issues between SHP and Raster file

I am having an issue with the CRS of a given Aster DEM. I have downloaded a Aster DEM from www.oziexplorer3.com which comes with the EPSG:4326 - WGS 84 as the CRS. This is a DEM from Gabon, and all ...
3
votes
1answer
78 views

How do I select all outermost features

Is there anyway in QGIS that I can select all the outermost features on a map? On an island that would be all that have a coastline. edit: This is what I'm trying to select:
0
votes
0answers
24 views

How to build an optimization model? [duplicate]

I want to make a model using QGIS. Is it possible? Then how can I develop a model. can anyone help me?
0
votes
0answers
61 views

qgis: module crashed or killed

using Grass 6.4.3. via Qgis 2.2.0 Valmiera (standard installation package): Why would Grass modules suddenly produce a "module cashed or killed" error. specifically in relation to r.surf.idw2 and r....
2
votes
1answer
660 views

How to create atlas along line/route in QGIS

I'd like to create a mapbook along a given route that is designated by a single linear feature. Is it possible to have QGIS (2.2) automaptically compose a series of pdfs that over lap by a given ...
0
votes
0answers
49 views

QGIS - Obtain elevation profile [duplicate]

I wish to obtain a bathymetry profile along the selected path (Google Earth calls this feature "elevation profile". Can QGIS 2.2 provide this? I created a layer using the WMS service to load the ...
1
vote
1answer
114 views

QGIS - View bathymetry info in the status bar

PolyGo suggested that I split my earlier twofold question into separate questions. So: I am new to QGIS or any GIS software so please forgive me if the answer is obvious to you. I wish to view the ...
0
votes
1answer
136 views

Modifying Fields in QGIS

I'm pretty new to Quantum GIS, and I was looking to add zeros to a field I was having some trouble with. I learned through browsing a few posts here that existing fields can be modified by defining ...
0
votes
0answers
75 views

Enlarge region/features in shape file

I'm completely new to QGIS. I have a shape file over the counties in Denmark (see here for what the shape file looks like). The counties around Copenhagen are rather small and I'd like to add an ...
1
vote
1answer
109 views

Unable to install QGIS 2.2 successfully?

I'm having problem in installing QGIS 2.2. (64 Bit). After downloading & installing, when I click the OSGeo4WShell, I get a message: C:\***.exe not a valid win32 application and ends with: ...
0
votes
0answers
191 views

Save map canvas as image with drawings

Is there any way to save the map canvas as an image, with the drawings on map? I draw a line on map, and saved it as image, but only the map saved(without line). I used the following code.. iface....