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

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0
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7 views

How to extract polygons from a road network?

I need to extract faces (or polygons) from my road network and calculate their areas. I mainly use Arcpy packages but even if you know it in QGIS APIs, I'd appreciate if you'd share it with me. If it ...
0
votes
0answers
88 views

How to show world map with Lizmap

I would like to show world map with Lizmap web client but I don't know how to do. Could you show me how? I follow this tutorial: http://hub.qgis.org/wiki/lizmapwebclient/Installation_en for install ...
1
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0answers
12 views

qgis-web-client stuck on “Loading map” on some maps

Some maps work for me to load, while some of them never do. They do load the layer names, but nothing more. The javascript console in Chrome returns this: Uncaught TypeError: Cannot read property ...
2
votes
1answer
33 views

Trouble calculating areas in QGIS using field calculator

I am testing various projections to calculate areas using ICES statistical shapefiles and the QGIS field calculator. I am using ICES areas downloadable from the following link: ...
3
votes
2answers
847 views

Simple automated way to split all lines in layer at vertices using QGIS?

I want to automatically split all lines in a QGIS layer at their vertices (like this). I've done a google search and found this article, which is quite close but the workflow is complicated. Because ...
2
votes
2answers
42 views

How to open the “File Browse” dialog in Windows from a PyQGIS plugin code?

I am in the process of developing a plugin for QGIS using Python. Note that this is my first plugin, so the query could be quite basic... I have used this Digital Geography link to create the basic ...
0
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0answers
9 views

QGIS WMS Server Search List of Results

In the "Add WMS" dialog on tab "Search for Server" you can put in some keywords and get a list of WMS matching this topic. My Question is: How could a WMS becomes a member of this resultlist?
2
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0answers
30 views

How to make serial maps from template?

I have developed a stand-alone python script for making serial maps using PyQGIS library. The maps should follow a specific format that is indicated by a template .qpt file. This template file is ...
1
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0answers
12 views

Positons from GPS lanes inside a polygon

i have a lot of lanes like the orange lanes at the below picture (latitude and longitude values). Now i need all values from each lane inside the red polygon. What is the easiest way to realize ...
8
votes
5answers
212 views

GIS analysis to find duplicate geometries

I have a big shapefile that contains all the buildings and houses of the town that I work in (approx. 90,000 features). The data of the buildings/houses are saved by the town's surveying engineers and ...
1
vote
0answers
33 views

Making air pollution model in QGIS [on hold]

Im writting bachelor thesis about air pollution from point source and i want, to put it to GIS. But i dont know really how ... Im working with Gaussian plume model, so I have pollution concetration ...
3
votes
2answers
272 views

Load and display a layer using PYQGIS

I'm having a go at using pyqgis from within the QGIS python console to load a layer from SQL Server and display it. I feel like I'm part way there but I'm having a real issue getting the layer to ...
4
votes
2answers
37 views

How to achieve “Flat-End” line buffers in QGIS?

I need to buffer a series of lines by 40m, however I only want the buffer to come off the sides and not off either end of the line. I know in ArcGIS there is a "flat-ends" tickbox that achieves ...
3
votes
1answer
53 views

QGIS 2.4 access .mdb add error

So I followed the instruction here: Can QGIS read an ODBC connection? for adding a .mdb into QGIS. There are great instructions about 1/3 of the way down. But I still can't get it to open. I on ...
1
vote
2answers
149 views

Using Qt Designer to Create a Form in QGIS that can search for a specific point in a layer

Good Day! I would like to ask if you can create a form in Qt Designer to create a form that can search for a point on the map using data that the user will provide such as the Name. I am currently ...
0
votes
1answer
119 views

Import DEM into PostGIS for QGIS

I'm a complete GIS newbie so sorry if I'm using the wrong terminology in searching for a solution to this... I'm trying to import a DEM into PostGIS and display it in QGIS. The data is from the EU-DEM ...
1
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0answers
15 views

How to merge elevation from a raster image onto a shape road network with QGIS? [duplicate]

I have a shape file with Stockholms road network and a raster image with elevation data from the same area. Is there any way to merge the two somehow, either by adding the slope direction as ...
6
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3answers
123 views
+50

Cutting out depth information in raster. Calculating volume in Qgis

I am trying to calculate habitat volume for around 30 fish stocks in Qgis. I have habitat areas (shape files) and Bathymetric information (.tif file). I believe I can calculate the entire volume of ...
3
votes
1answer
175 views

Continuous color band for a raster legend in QGIS composer legend

I'm looking for a way to insert continuous colour legend for a raster layer. I managed to create discrete symbols with values along the bar, but I would like to have a continuous bar with some values ...
2
votes
1answer
33 views

How to merge shapefiles of two countries with QGIS [duplicate]

I want to merge the shapefile of Nigeria and Cameroon admin level 1. I downloaded the files from gadm but I cannot merge the files with QGIS or find a shapefile of Africa having countries at states ...
1
vote
5answers
825 views

Unable to install ECW support on lubuntu 14.04

I try unsuccessfully to install the ECW support (mainly to use ECW file in QGIS 2.2). We attempt to follow and adapt the howto provided by makina-corpus. My first supprise was the repository ...
1
vote
1answer
21 views

Difference between ETRS89 / ETRS-TM32 and ETRS89 / UTM zone 32N

In QGIS I can choose among other things between "ETRS89 / ETRS-TM32" and "ETRS89 / UTM zone 32N". In my test project both projections displayed the layers at the very same place. So, where is the ...
0
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0answers
10 views

export qgis point symbols per feature

I am currently trying to export the drawn symbol in a QGIS map for a webmap. The current approach is to extract the properties: if i.rendererV2().dump()[0:6] == 'SINGLE' and i.geometryType() == 0: ...
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0answers
15 views

How to calculate fastest bicycle routes in Stockholm with QGIS?

Hello StackExchangers, I would really appreciate if expert users could point out a few directions for me, this is what I wanna do: Access an online map from my iPhone that gives me the possibility ...
3
votes
1answer
86 views

Shortest distance from polygon centroids to a line in QGIS

To get the distance of each polygon centroid from a line, I have tried the Distance to nearest hub algorithm from the Processing Toolbox. The distances I got from the algorithm did not seem correct, ...
2
votes
2answers
320 views

How to find the nearest single point?

I have two shapefiles containing each one set of points, set A and set B. One set is my random selection (set A), the other is a list of communities (set B). For each point of the random selection ...
2
votes
1answer
40 views

QGIS crashing when using 'save as' to save a new projection

Every time I try to save a layer with a new projection using 'save as' my QGIS crashes. The new files are there but they seem false. Please see two screenshots attached, one before and one after I ...
2
votes
0answers
34 views

Google Earth / QGIS projection (great circle line)

Here is my question: 1- Based on a long distance segment ( approx 2000 km) drawn on Google Earth and imported as shapefile in QGIS I want to obtain a terrain profile based on "Terrain Profile" ...
0
votes
1answer
31 views

Qgis - How to connect to an Oracle DB (SDE)

I want to access an Oracle Database (with SDE) from Qgis 2.4. I have tried many different options from within the window Create a new Oracle Connection but I always get an error message (ORA-12514: ...
3
votes
1answer
43 views

Ripley's K function in QGIS Chugiak 2.4

I'm a noob user and I need to apply the Ripley's K-function on a point pattern in QGIS 2.4 Chugiak, but I don't know how to do. I think I need to use some plugin or extension (maybe GRASS, R or ...
1
vote
0answers
33 views

using r.volume model GRASS plugin in QGIS

I am calculating volume of bathymetric data in the form of a clipped raster in GRASS with a Custom Lambert projection centered around 70degrees North, using the module r.volume in GRASS. Side note: ...
0
votes
2answers
305 views

How do I successfully install the LecoS plug-in for QGIS 1.8

I have been trying to follow the instructions given here, but repeatedly get an error message pop-up titled "Mount" stating Access is Denied. Does anyone have a solution please?
1
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0answers
12 views

Does qgis support postgresql range types?

I added a postgis layer with date range column in Qgis but that field is not listed in Qgis.
3
votes
1answer
28 views

How to perform raster Overlay Analysis using QGIS?

I tried to do a raster Weighted Overlay Suitability Analysis to find the best location for home lands using QGIS. Used layers are: School location (point) Crime locations (point) Road (line) Water ...
2
votes
1answer
21 views

How to make my PostGIS vector layer in QGIS visible?

I have loaded a shp file (simple polygon with one entry) into PostgreSQL 9.3 (with extention PostGIS v2.1.3). I now want to load this layer into QGIS (v2.2.0 Valmeira) via the "load Postgis layer) ...
2
votes
0answers
30 views

Chinese characters appear in attribute table

I am running QGIS 2.4 on a mac, and all of the text in my attribute tables appears in Chinese. I've tried uninstalling and re-installing, changing the locale to U.S. English, and nothing helps. I've ...
3
votes
1answer
57 views

Are there any geology symbol libraries for QGIS?

are there any structural-geology symbols libraries (and geology in general) for QGIS? Many thanks
2
votes
1answer
27 views

How to Raster Layer checked status change?

I make plugin with use QListWidget. Items of QListWidget is Raster Layer name. When selected items, same name layer checked status changing. current my code is items = ...
2
votes
1answer
29 views

How to open a compressed GDB in QGIS?

Looking for help with a problem in QGIS. I'm using QGIS 2.2 and 2.4 for potential analysis of surfaces. Data are based in gdb datasets that were created in ArcGIS and made ​​available to me. Some gdb ...
6
votes
4answers
2k views

Is it possible to create 3D dxf with OGR?

Does anyone know if it's possible to create a 3D dxf with OGR. I would like to assign our contour lines a z value and export them to dxf for some cad work. PS I know FME can do this, however I would ...
4
votes
1answer
1k views

Union, Dissolve, Buffer — multiple layers, all in one step?

I'm a new user of Quantum GIS (1.7.3) and I need to repeat a task multiple times, so I'm wondering if there is a quicker way to do the following (with three or more polygon layers - each layer has a ...
0
votes
0answers
32 views

QGIS WFS Error - Could not commit changes to layer

I have a PostGIS database being served by Geoserver. I can load the layers I want into QGIS no worries; however whenever I try to edit the layer I get this error message: Could not commit changes to ...
2
votes
1answer
238 views

Creating buffers that will not overlap in QGIS

I am dealing with a .shp with a number of points in it. The distances between points range from ~300m to 5km. I wish to create a 1 km buffer around each point with as little overlap as possible. Each ...
1
vote
2answers
196 views

Add custom CRS - 2.2.0 Valmiera

i've builded a custom proj.4 library, tested it by command line (proj and cs2cs) and with postgres/postgis. All works fine. Now i'm trying to make the same with Qgis 2.2.0. I've replaced the original ...
2
votes
0answers
22 views

Merge vector layers to fill gaps in QGIS

I have a zip code map which I added per zip code data too (a regional director for each zipcode), and then dissolved the map based on the director attribute. As you may or may not know, zip codes are ...
1
vote
0answers
17 views

Correct folders and conf settings for qgis-web-client with qgis-server?

I have setup QGIS server using this guide sucessfully and would now like to setup qgis-web-client alongside it. My QGIS server folder is: /usr/lib/cgi-bin For qgis-web-client I have followed the ...
2
votes
1answer
18 views

How to style a Vector layer in QGIS using a numeral of an attribute

I have a simple vector layer in QGIS that I would like to style with numerals based on the ID attribute. For instance, point with ID 1 will show up as the numeral 1. Is this possible with default ...
1
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0answers
26 views

QGIS 2.4 match borders of two shapefiles

I have two shapefiles of the same place, but one of them is wrong and I need to match the borders with the other shapefile. I´m using QGIS 2.4 and couldn´t do it so far. Thanks.-
1
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0answers
22 views

QGIS 2.2.0-Valmiera 64bit on windows 8.1 displays error while creating ROI in SAC plugin

I don't know what happened while creating ROI during Classification using Semi automatic Classification Plugin 3.1.0 "Rome" installed on hp Pavillion i7 with windows 8.1 When i started to generate ROI ...
2
votes
1answer
18 views

Importing a temperature raster layer to QGIS project

I am trying to add raster layers to depict minimum monthly winter temperatures for two counties in Ireland. I tried importing as tiff., ADF., HDR., and bil. files. I managed to add them in any of ...