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

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How to develop QGIS Plugin to fully run Spatial Queries With PostGIS?

I'm developing a QGIS plugin that fully run spatial queries with PostGIS. Actually I developed all spatial queries wish need some adjustment. I'm looking for some ressources or documents to know how ...
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2answers
12 views

Rotating labels in QGIS

I have a question concerning label placement in QGIS. I'd like to rotate every label by 180°. Therefore, I set the rotation value to 180 (I've tried different ones as well as different variable types) ...
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8 views

GML geometries are not rendered

I tried to view a GML file and I have a problem with viewing of polygons from a feature type ps:ProtectedSite with QGIS. This feature contains a MultiSurface with a surfaceMember with a ...
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19 views

How to fix the error between two coordinate systems?

How do you think the shift of line is due to morphological change of river? Or it is due to deviation between two coordinate systems? Please point out !!
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0answers
19 views

Layer Order panel seems to be broken in QGIS 2.10, it duplicates layers

I'd like to just confirm that a problem I am having in QGIS 2.10 is not unique to me. I am using the Layer Order panel to control the rendering order of layers in my projects, it's very useful when ...
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1answer
11 views

Merge and export two layers that utilize blending modes

I have a new question that I'm trying to solve. Spent more time than I can to admit trying to come up with a solution that doesn't require bringing the layers into Photoshop or the GIMP (which would ...
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1answer
14 views

Can I use TIFF files for zonal statistics in QGIS or ARCGIS?

I am completing a remote sensing paper and am doing most of the work in PCI Geomatica, where I have 2 separate files. One from running a texture analysis algorithm containing 6 band layers from a ...
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0answers
23 views

How to place coordinates points on a vector layer?

I have got GPS coordinates collected from a number of farms in my country (Malawi). But when I plot these GPS coordinates on a vector layer (my country map) using QGIS, the points are falling outside ...
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9 views

Compare similar lines and update layers

Here there are two layers with the representation of the streets and the idea is: We want to update the most recent layer (with the red line) with some of the data storaged in the other one (the light ...
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9 views

What is the correct way to run a python script in QGIS Open Project macro?

This code (answer from @gcarrillo about other question - Is there any way to freeze the layer names in the TOC?) runs fine on python console and inside a plugin. But now, I tried put it within the ...
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0answers
20 views

Minidump on exit in QGIS (2.8.2- Wien) 64-bit version when using GDAL in plugin

I am working on a plugin for QGIS that is working fine on 32-bit versions but I am having some problems while using it on the 64-bit standalone installation package. I have tried on several machines ...
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2answers
85 views

Where to download QGIS 2.10?

Is QGIS 2.10 Pisa for Ubuntu/Windows already available?
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19 views

How to call the Qt UI of a script?

I'm pretty new in the python world, and I'm working with the python console inside QGIS (Master version on a Debian machine). I have written some scripts, all of them are in the same directory (e.g. ...
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0answers
21 views

QGIS - shp to dxf conversion problem while opened in Autocad

I have a group of vector files that I intend to convert to "DXF" format. But after the conversion, only contour lines(white lines in the red polygon) are not displayed in Autocad. I read some related ...
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1answer
21 views

Print composer - legend - graduated

I have a map with graduated symbology, with 328 unique values. I would like add a legend to my map (as in the picture), illustrating that light blue indicates low values and dark blue high values. I ...
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0answers
18 views

QGIS: drag zoom via keyboard shortcut/ mouse wheel?

to zoom to a rectangle in ARCGIS i always clicked and held the mouse wheel while pushing the control key. This was a very efficiant way for me to navigate through a map. Is there anything similar in ...
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33 views

QGIS - Simplification process creates a new polygon - how to avoid it?

I am trying to simplify a layer made of polygons. I have used different methods but the new simplified layer has a polygon which intersect with itself, thus creating a "new" polygon. Please see ...
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15 views

QGIS QgsLayerTreeGroup signal “currentLayerChanged”?

In a pyqgis context, I use the "currentLayerChanged(QgsMapLayer *)" signal of the QgisInterface class to do something when the current layer is changed, but I need now to do the same when I select a ...
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10 views

How to Change Precision of Export / Add Geometry Columns field

I would like to display the coordinates of a number of points on a map. I can use Vector > Export / Add Geometry Columns which adds coordinates to 6 dp. However as I am using a UTM-type projection ...
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2answers
20 views

QGIS Editing: move - both - nodes after Cut has been performed

I just ran into unexpected behavior while editing a polygon shapefile in QGIS 2.8.2. Scenario: A polygon: Then I cut that polygon into two seperate poygons: Then I use the Node Tool to move a ...
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1answer
28 views

How to completely uninstall and remove QGIS 2.8.1

I want to uninstall and completely remove QGIS installation from my computer(windows vista). I have uninstalled it and when i try to reinstall it says it is already installed on the system.
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17 views

QGIS import OpenAIP

I have files from OpenAIP (http://www.openaip.net). How can I import them ? Format available are : .aip .cup .dat .aip is xml file. For point : <OPENAIP VERSION="960678" DATAFORMAT="1.1"> ...
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2answers
17 views

Embed Sound in Leaflet Popup with QGIS

I was wanting to embed some animal sounds in a leaflet map my son and I are creating. Have images embedded, but would like sounds in the popup if possible. Like embedding images, can this be done ...
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15 views

How to create new field using the values of one attribute column multiplied by a constant number in Qgis or ArcGIS [duplicate]

I have point data that has a small length attribute - I want to times this length attribute by a constant number (I need to trial a few different constants) to find the diameter of a protection zone ...
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0answers
17 views

QGIS dissolve by attribute and retain primary polygon attributes

I have a parcel shapefile. Many of the parcels have been combined over time, but the shapefile still represents the original parcel boundaries. The attribute table has a field for the original parcel ...
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1answer
16 views

Loading GeoServer WMS raster layer in QGIS Python console

I am using the following snippet to load a raster layer deployed under wms service using geoserver, in qgis python console. I am getting False output. Any idea? registry = ...
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12 views

PyQGIS Standalone Crashes python.exe when zooming out too far / Process finished with exit code -1073741819 (0xC0000005)

I have the following PyQGIS Standalone App which is working fine so far. One little problem is that if I zoom out to the MaxExtent(by scrolling the mousewheel) the app crashes python.exe so that the ...
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1answer
24 views

Error: Algorithm not found (QGIS)

I wrote the following code using QGIS'API. import os from qgis.core import * import qgis.utils prefix_path = os.environ['QGIS_PREFIX_PATH'] QgsApplication.setPrefixPath(prefix_path, True) ...
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2answers
37 views

Easy Custom Labeling tool: How do I remove label arrows?

I am labeling a lot of features and the Easy Custom Labeling tool is helping me to move every label to the desired position. I also like that the tool adds arrows for labels that I moved but sometimes ...
2
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0answers
25 views

Can you load WFS uncached in QGIS

I think this might be a bug, but we've just installed QGIS 2.10 and the WFS seems to be working strangely. When you load a WFS which is not cached the system loads all the visible features as ...
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1answer
13 views

gsb projection file for qgis under MAC OSX

I'm trying to create a new projection inside wgis. The projection includes a gsb file. With the Windows OS is easy to implemnet that: you just need to place the gsb file inside the ...
2
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1answer
30 views

How to add a message bar to custom canvas?

There is a simple code to add message bar to main window in QGIS: iface.messageBar().pushMessage("Hello","World") My question is how to add bar to my custom canvas canvas = QgsMapCanvas() in ...
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45 views

Remove multiple fields from multiple shapefiles using a python script [duplicate]

I'm using the python console of QGIS 2.8.1-Wien. I have a shapefile with many fields in the table that I want to remove them. I tried to use this geoalgoritm as: ...
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34 views

need information about openstreetmap (osm) [on hold]

I am looking for information or code sample to use OSM map I am working on a project that need to read OSM and to display it I intend to use the QgsOSMDownload and more But at this time i need ...
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0answers
18 views

import qgis.core problem with QgsFeature and QgsGeometry ImportError: DLL load failed: The specified procedure could not be found

I've tried several previous answers to similar questions - no luck. I've tried everything, nothing seems to work. This is the error I'm getting Traceback (most recent call last): File ...
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13 views

Qgis Time manager raster error

I would like to give a shot to the Time manager in Qgis with some raster datasets. I load 2 rasters (both single band, 32bit float). I add the first one in the Time Manager window with the start ...
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12 views

How to graph a line given a great distance (e.g. 100km) and the angle?

I'm new to QGIS and I'm trying to graph subduction zones and I was given the starting point (in latitude and longitude), the length (in km) and the angle (in deg). How is it graph correctly? I tried ...
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1answer
27 views

How to measure the distance between multiple points and multiple polygons?

I'm trying to find a quick and accuarate way to measure the distance between 3 survey sites and all the designated sites within 10km. The survey sites are on a point vector layer and the designated ...
2
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1answer
27 views

QGIS Heatmap values change when imported into ArcMap?

I am creating a heatmap layer from QGIS and importing the TIFF into ArcMap. When I import the file into ArcMap I notice that values are different. For example the max value in QGIS is 8.92454, but ...
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1answer
15 views

Semi Automated Classification plugin (QGIS) error when trying to create ROI

When I try to create a new ROI through Semi-Automated Classification plugin (SCP) for QGIS, I keep getting a message saying: "It appears that SciPy is not correctly installed. Please, see this page ...
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0answers
19 views

How to remove las2dem streaks from raster dem

I've created a series of DEM files using the las2dem tool from LAStools, however since I don't have a licensed version they have black streaks running across them. Does anyone know a good method for ...
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1answer
32 views

Update Column in QGIS

I would like to update columns in QGIS something like making MAPINFO . Contains , is Within, intersects ) and get values ​​such as sum, avg, propsum , count Is it possible to do this with any tool in ...
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0answers
15 views

Normalized Difference Built Up Indice with a threshold value in QGIS modeler

I want to use the modeler in QGIS, model the NDBI with a threshold value in order to produce a binary image. positive values = 1 and negative values = 0 my question is about which tool I can use in ...
3
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1answer
39 views

Overlay Analysis in QGIS (or Preferably Python)

I would like to perform an overlay analysis in Python or QGIS to output a list of each shapefile that falls within certain boundaries. I have unsuccessfully tried to use the Spatial Join, Intersect, ...
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1answer
33 views

Interpolation extent

the following pics will hopefully explain my problem. After interpolation an clipping the grid I get the result you can see on the pic. Next to the boundaries there are a lot of gaps caused by the ...
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1answer
39 views

How to merge two lines of polygons?

In QGIS 2.6.1, I have merged two polygon shapefiles. After the merge I am facing a problem at boundaries. So I thought of changing Polygon -> lines, manually deleting one of the lines at the ...
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1answer
20 views

How to show objects inside an area?

I have two different shape: point shape file with many elements area shape file with many regions I need to create a rule where I need to colur differently the points in some areas, but the areas ...
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1answer
37 views

Is there a way to set the character encoding for all layers at once?

I have to set the character encoding forall layers from system to UTF-8. Is there a way to change this in all loaded layers at once? I'm using QGIS 2.8.1 on Windows 7.
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2answers
49 views

Problem when opening a raster layer

I am a news user with QGIS API C++. In order to feel good with it I try some little program to explore class. I have download the tutorial 4 of the QGIS and adapted it to the 2.8 version but when I ...
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2answers
28 views

How to use r.mapcalculator to change values within a raster cost map to negative

I have created a cost map in r.cost module in GRASS (through QGIS). This is actually a distance map from a protected area and distance from protected area has been calculated in both directions. How I ...