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

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1answer
28 views

Speeding up length calculation in QGIS 2.0 Python plugin

In a qgis 2.0 plugin for windows, I calculate length and update a field with the values. It works, but takes a lot of time. Execution for this part only takes about ten minutes. Can anyone suggest ...
2
votes
1answer
33 views

Why is too long connecting to Oracle Spatial database from QGIS client?

I am having trouble connecting to an Oracle Spatial data with QGIS client. I use QGIS Version 2.2 (Valmiera) to connect to a database schema in Oracle Spatial. I asked our DBA access to our database ...
2
votes
2answers
69 views

How to fix unreachable nodes in QGIS GRASS network?

I have created a network with the GRASS module v.net. But when I try to create the travelling salesman path with v.net.salesman, I get: Destination node 9383 is unreachable from node 9398 If I ...
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0answers
15 views

Print Custom Feature Form using PyQGIS

I recently asked a question and accepted the answer, as it was a good guide on accessing the print composer using python. However, I am still looking for a way to print the custom feature form. Does ...
3
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1answer
32 views

Superimpose OTB application via Sextante cannot load parameter

I am trying to perform a pansharpening using OTB via sextante. According to the cookbook I first need to superimpose the Pan and XPS images: http://www.orfeo-toolbox.org/CookBook/CookBooksu36.html ...
4
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1answer
58 views

Question about ArcGIS vs. QGIS for kernel density estimations

It appears from the QGIS documentation that the Heatmap Plugin can generate a kernel density surface from a point map and make use of the attributes of the original points to influence this surface ...
2
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0answers
50 views

Why do comparisons in QGIS 2.4.0 Raster Calculator return -3.40282e+38 aka no_data?

I tried to use comparisons as conditional statements in QGIS 2.4.0 raster calculator. My statement is: (a < 230) * 230 + (a >= 230) * a The expected result is raster a with all values lower ...
3
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1answer
125 views

QGIS 2.4.0 Chugiak How to remove topographic effects like shadows from landsat image

I am using QGIS 2.4.0 Chugiak on my windows 8.1, for classification of landsat 5-7 image that contains hilly mountains with dense forest and 60% area are plains. I am classifying through ...
2
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0answers
66 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 ...
1
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1answer
43 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 ...
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0answers
16 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?
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1answer
50 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 ...
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0answers
56 views

Making air pollution model in QGIS [closed]

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 ...
1
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0answers
18 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 ...
2
votes
1answer
46 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 ...
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0answers
22 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
27 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 ...
1
vote
1answer
37 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 ...
4
votes
2answers
53 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
64 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: ...
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0answers
36 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
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1answer
66 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
73 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 ...
2
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0answers
44 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" ...
2
votes
1answer
31 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 = ...
4
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1answer
87 views

Are there any geology symbol libraries for QGIS?

are there any structural-geology symbols libraries (and geology in general) for QGIS? Many thanks
3
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1answer
157 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 ...
2
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0answers
34 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
1answer
76 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
0answers
46 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 ...
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0answers
35 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.-
2
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0answers
36 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

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 ...
2
votes
2answers
169 views

How to connect QGIS 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: ...
2
votes
1answer
44 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 ...
9
votes
5answers
281 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 ...
3
votes
0answers
42 views

How to snap and move circles by the center?

I have a point layer, and a polygon layer with buffers of a given radius around each point. I need to move points, and check that each buffer is not above forbidden land/plots. In autocad, you can ...
2
votes
1answer
22 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 ...
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0answers
23 views

GPS with QGIS--what happened to the capture point?

I have been using QGIS for years but when v. 2 came out and important functionality seems to no longer work. In 1.8 the "capture point" or "capture line" buttons on the GPS panel would work. Ever ...
2
votes
1answer
26 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) ...
0
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0answers
70 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
2answers
58 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 ...
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0answers
27 views

Identify features button disabled

I am new to QGIS. I have installed 2.4.0 and opened up a .qgs file without problems. But the "identify features" icon is disabled/blacked out and not functioning. Please find screenshot below. Why do ...
2
votes
1answer
64 views

How to cut and paste polygons in QGIS so they don't overlap?

I use QGIS, and I need to cut and paste polygons so they don't overlap. Here's what I mean: I have shapefiles for cities that I'm pasting into a new polygon shapefile. I also have shapefiles for ...
1
vote
1answer
57 views

Update QGIS on Mac OS X

I would like to update QGIS from 2.2 to 2.4 on Mac OS X (10.8) but I cannot find how to do so. Do I have to uninstall and re-install all from KyngChaos? If so, I would therefore lose the extensions ...
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0answers
37 views

midpoint of segments in QGIS determination

Gene thanks for your note on the problem yesterday ... This is a follow up to a question I posed before (How to find the middle point of a line in QGIS - Where to place input file name). Errors coming ...
2
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0answers
33 views

Correct syntax for retrieving features from GML format in OpenLayers

Yesterday I made with qgis the shapefiles of my town and now I wanted to add them in a web application I'm making with OpenLayers. The problem is that, while it loads them perfectly with the wms ...
3
votes
2answers
120 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 ...
9
votes
1answer
204 views

Can PostGIS and QGIS provide dependable multi-user editing?

After considering a few options, I'm trying to give my 15-20 QGIS 2.2 users the ability to concurrently view/edit one or two basic point PostGIS layers, largest one has just 16,000 records. I've ...
2
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0answers
37 views

QGIS There isn't entry in geometry_columns!

In PostgreSQL v9.3 with PostGIS v2.1 extensions I created a view from two tables (sites & visits). The site table contained a point geometry column (the_geom), which was included in the created ...