Python bindings for QGIS.

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903 views

How to get pixel size/cell size of raster layer?

After much searching, I've still not been able to figure out how to perform what seems like a simple function: I'd like to get the pixel size/cell size of a raster layer using PyQgis. Is there any ...
5
votes
2answers
660 views

Load and display a layer from SQL Server 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 ...
5
votes
0answers
544 views

PyQGIS CRS on the fly reprojetion [closed]

As a first step of a pyqgis plugin I'm trying to import several shape files at once. To get them aligned, using the GUI, I'd enable on the fly reprojections and set the project crs to WGS84. I'd then ...
4
votes
2answers
480 views

Using Python and open source modules, how can I perform Raster Calculator functions?

I would like to perform mathematical functions similar to those you would use Raster Calculator for in ArcMap, however I'd like to do it in Python without using the Arcpy module. I have the osgeo ...
4
votes
1answer
990 views

Get a pixel value

How can i do this operation: I want to get a pixel value fro the satellite image (Landat, GeoTIFF, 7 bands) using qgis-python. What operators should i use? (for example in qgis's Python Console) ...
4
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2answers
1k views

How to automatically reloaded raster layer if source is changed in QGIS?

How to automatically reloaded raster layer if source is changed? (The path is the same but inside source file are changes) I use: qgis.utils.iface.mapCanvas().refresh() but layer not refresh. # ...
4
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3answers
2k views

How can I specify the CRS of a raster layer in pyqgis?

I manipulating netcdf raster data from the QGIS python console. The metadata of my netcdf file does not provide the Reference system. However I know it is 'EPSG:4326' I am writing a python script to ...
4
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2answers
369 views

How to identify polygon/point shapefiles in python?

I have a script which performs various functions on shapefiles, most of which are polygon-based. However, some shapefiles are point-based and I have to specify where these files are by editing the ...
4
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2answers
2k views

how to for loop a folder to batch clip rasters by polygon using python and QGIS

I am using python and QGIS 2.0. I am trying to clip rasters in a folder by one polygon feature. It's the first time for me using (let's say) "PyQGIS", I was used to arcpy before. Anyway, I don't get ...
4
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3answers
1k views

How to find the polygon inside which a point lies?

I have a layer with polygonal features. Each feature has attributes and values. I also have a list of co-ordinates and I would like to know which feature (or polygon) the co-ordinates lie in. Could ...
4
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2answers
139 views

Adding a vector layer at QGIS start

I have added a shape file in QGIS using Python plugin. I want to add this shape file when QGIS is loading so i have to add code in the initgui() method. I have used following code in the initgui() ...
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2answers
1k views

How to get field names in pyqgis 2.0

I am trying to change an plugin from QGIS 1.8 to 2.0. In the 1.8 version I create a table of the field names like this: layer = vlayer provider = layer.dataProvider() feat = QGSFeatrue() allAttrs = ...
4
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4answers
472 views

How to display a “Save As” dialog for raster files?

I'm writing a QGIS plugin in python. I need to show a "Save as" dialog window in order to allow the user to select the path of the output raster file. Do I need to create a QFileDialog and manually ...
4
votes
1answer
1k views

QGIS Zoom from python console

What are the commands to apply all types of zoom (full, on selected layer, etc.) in python console? I'm searching both on pyqgis cookbook and API documentantion, but I'm not finding anything ...
4
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2answers
679 views

How to load memory output from QGIS processing?

Many processing algorithms have an option to save output as memory. If ran from toolbox, this works fine, because you can tick the "Open output file after running algorithm" box. Looking at the ...
4
votes
1answer
276 views

How to programmatically detect a canvas refresh or pan/zoom in QGIS

For my python plugin I would like to remove a VertexMarker when the user pans/zooms there map. Which is the best way to detect a canvas refresh or pan/zoom carried out by the user? Can you suggest ...
4
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2answers
1k views

How to change the color of a vector layer in pyQGIS?

Is it possible to change the color while adding a vector layer? I have a vector layer with water areas and want to load it with a blue color style. The layer is added with: ...
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2answers
797 views

How can I add OpenLayers layer from the python console?

I am new to the python console. How can I add a layer from the OpenLayers plugin from the python console? Thank you
4
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1answer
985 views

How to merge shape files with attributes from a python script in QGIS?

I have some shape files. They are all the same kind of shape and all have the same attributes. If I wanted to merge them manually the "Vector/Data management tools/merge shape files to one" works ...
4
votes
2answers
622 views

How do I set layer transparency in QGIS 2.0 with Python?

I have a raster layer loaded in QGIS and I'd like to be able to set its transparency via the Python console. I'm new to the API and have not been able to find out how to do this. Any help would be ...
4
votes
1answer
1k views

Using in-memory vector layer with QGIS processing / SEXTANTE

I'm trying to run the qgis:clip algorithm from console, but am getting an error when using an in-memory layer as the overlay parameter. Is this to be expected, or am I doing something wrong? Code: ...
4
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1answer
973 views

How to zoom to a selected feature with pyQGIS

I want to create a function that selects a feature and zooms to it (similar in QGIS). Therefore there is following function: QgsMapLayerRegistry.instance().addMapLayer(self.vlayer) def zoomTo(self): ...
4
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1answer
621 views

How can I create a new layer from the currrent selection?

Is it possible to create a duplicate layer, only displaying the selection from the layer you are duplicating in QuantumGIS? Simular to ArcGIS -> Create Layer from Selected Features. I looked at "How ...
4
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1answer
246 views

clip geometries in postgis table if they are inside a polygon

I have polygons defined in KML files just like this one, which I can easily parse. Example: <Polygon><outerBoundaryIs><LinearRing><coordinates> -91.463940,40.372660,0 ...
4
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1answer
741 views

“Couldn't load PyQGIS” Error running QGIS on Ubuntu 14.04

I have installed QGis on Ubuntu 14.04 from the QGis stable repository; it went fine with no errors reported. But when I launch QGis I get this huge window with the following message: Couldn't load ...
4
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1answer
1k views

How to find all intersections and count lines arriving at each intersection?

I'm having a hard time getting off the ground with this, and am trying to move away from ArcGIS / arcpy. I have a shapefile with a network of polylines. I want to find/count all 2-way intersections, ...
4
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1answer
56 views

Loading same layers every time

I recently started using Qgis python console for Qgis development. My first task is to load the layer and print its attributes.I firstly load a point layer using code mylr = ...
4
votes
1answer
116 views

Problem with performance when loading PostGIS layer using pyQGIS

I'm having a question on loading a PostGIS layer into the project from my QGIS plugin. The code is like this: uri1 = qgis.core.QgsDataSourceURI() uri1.setConnection(str(host), str(port), ...
4
votes
2answers
2k views

Setting the extent for a QGIS map using python

I am writing a stand-alone application in Python/QGIS that simply creates maps. I want to load vector/raster layers, set symbology, set extent At the moment, that is all! Currently I am just using ...
4
votes
1answer
244 views

How to auto-start a pyQGIS thread?

having build some (two) minor plugins, it's now time for me to link a few (perl-) applications to qgis. As there is no perl-interface in qgis I thought the best way to link both worlds together is a ...
4
votes
1answer
363 views

How change border line to no pen with python console?

From Python console I load a shapefile with qgis.utils.iface.addVectorLayer. How I can remove border lines (change to no pen) in the active layer?
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2answers
386 views

How to iterate over selected layers?

In QGis by pressing shift or ctrl keys a user can select multiple layers in toc. How can a python script iterate over selected layers? I'd expect a iface.selectedLayers() but I can find only ...
4
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1answer
671 views

How to Create a raster layer from a numpy array using pyqgis?

I am working on a plugin for Qgis to calculate spatial Kernel density maps. I have all the calculations working, all I am missing is a way to turn a Numpy Array, with density values into a multiband ...
4
votes
1answer
2k views

QGIS: How to load feature (.qml) styles from python? [duplicate]

Possible Duplicate: How to style a layer from console? I'm trying to set the styles for a vector layer by loading the .qml file in the python console. The qml-style file contains all ...
4
votes
1answer
606 views

How to load a postgres view using pyQgis?

Under Qgis 1.8 on Windows 7 I have this problem with my pyArchInit plugin: I need to load on the map canvas my geometries from a postgis layer. Till the 1.7.4 version I use the method explained on the ...
4
votes
1answer
382 views

How to move Layer to back?

from my Plugin I've loaded a rasterlayer using the following code: fileName = "/path/to/raster/file.tif" fileInfo = QFileInfo(fileName) baseName = fileInfo.baseName() rlayer = ...
4
votes
1answer
111 views

Access ESRI .GDB in PyQGIS

I can access ESRI .GDB data using OSGeo's OGR. The following code gives feature class names embedded in .GDB... from osgeo import ogr driver = ogr.GetDriverByName("FileGDB") data = ...
4
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1answer
180 views

Why are my calls to SAGA routines in QGIS not working cross platform?

The ability to write and run cross platform scripts for QGIS using python is OUTSTANDING! However, when I try to run the SAGA:MERGESHAPESLAYERS algorithm from a python script it works fine in windows ...
4
votes
1answer
322 views

Personal shell launcher for PyQGIS

I have changed a shell launcher found at http://inasafe.linfiniti.com/html/id/developer-docs/platform_windows.html as to fit my wish: setting the system environment variables to be able to use PyQGIS ...
4
votes
1answer
234 views

Can I add entries to the layerlist context menu?

I am implementing a python based plugin for use with QGIS 1.8. Most of it's user interface is contained within a QDockWidget but there are some layer specific controls I would like to append to the ...
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0answers
64 views

Using QGIS plugins from Python [duplicate]

Is there a simple way to automate calls to QGIS plugins from a QGIS Python script? Either from console or a plugin? I am ideally looking for a way to specify input/output parameters and bypass GUI. ...
4
votes
2answers
476 views

How to add a layer group using pyQGIS?

Good morning, I would like to know how I can create a new group in the layer manager using python code, someone could help me?
4
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0answers
102 views

Is there a way to run the spatial query plugin from QGIS python console? [duplicate]

I want to get all contiguous polygons for every county. In QGIS I can do this manually with a Spatial Query, but for a large data set this result impractical. Is there a way to run the spatial query ...
3
votes
2answers
955 views

Programmatically load composer from template and generate atlas using pyQgis

I Am trying to build a plugin to load a print composer from file, generate an atlas and export to image. So far I have been successful in loading the template and exporting it to image. I have been ...
3
votes
1answer
2k views

pyqgis: How to get features of selected geometries

I wonder if anybody could provide an example how to get the attributes of selected Features? I tried the folowing Code in the python Console - but I'm stuck at the point where I'd like to get the ...
3
votes
2answers
78 views

QGIS (2.4) keeps caching old Python code

I'm fiddling around with a piece of python code to use with form validation. It works fine, but the real problem is that QGIS refuses to acknowledge the changes I make in the script. Here's what I ...
3
votes
1answer
327 views

Converting models from QGIS to Python scripts?

I want to automate some tools for QGIS 2.0.2 using Python. Previously I have used ArcMap for automating tools and now i want to use QGIS. In ArcMap I used the ModelBuilder, and more specifically the ...
3
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3answers
892 views

How to add QGIS Python API Intellisense support in Aptana Studio3/Pydev

I'm developing QGIS plugins using PyDev in Aptana Studio 3 and I would like to know if it's possible to make it aware of the QGIS API and add some "intellisense" functionnalities when programming. For ...
3
votes
2answers
274 views

How to write an equivalent to MapBasic's CreateLine in pyQGIS?

I know this kind of question has been asked, in part, before - specifically: Seeing QGIS Python Commands and: How is object created as line using createline stored in .tab file? but this is a specific ...
3
votes
1answer
814 views

Get extents of vector shape features in python

i am just wondering if it is possible to iterate through vector features and return the extent per feature without clipping the vector shape? The code looks like this and comes from the ...