Python bindings for QGIS.

learn more… | top users | synonyms

4
votes
1answer
864 views

How to deploy a QGIS Python Standalone Application with minimum installation size?

I am trying to create a Standalone QGis Application using python. I was able to create the nice looking shapeviewer application by following the steps here. Now I would like to deploy this in ...
4
votes
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
votes
1answer
48 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
2answers
317 views

Best practice in writing automated tests for QGIS plugins

I'm looking for some best practice advice on writing automatic tests for QGIS plugins written in Python. I have written tests for Python scripts in the past using PyUnit (the unittest module), but ...
4
votes
2answers
972 views

How to use map composer in a stand-alone script?

I'm trying to follow the map rendering section from the pyqgis cookbook, but I'd like to test this as a standalone application. I can do the first part, using simple rendering, but I'm a bit stuck ...
4
votes
1answer
195 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
291 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?
4
votes
1answer
522 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
94 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
2answers
537 views

Rendering and Labeling Shapefile with PyQGIS

I've been running into a few problems working with the QGIS API for python. I've gotten more comfortable working in the python console in QGIS but I run into problems when I try to run the code ...
4
votes
1answer
468 views

Using the Processing Framework in QGIS 2.0

I am writing a plugin for QGIS 2.0, and I want to use the processing framework to call some functions. When I open the pyhton console inside QGIS, I am able to call it like this: >> import ...
4
votes
1answer
279 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
169 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 ...
4
votes
2answers
340 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
votes
1answer
198 views

How can I modify layer order with the QGIS python API [duplicate]

Typically, after a new_layer = addRasterLayer(...) that inserts new_layer before the active layer, I'd like to move it to the top of the table of contents. How to do it? I use an existing QGIS ...
4
votes
0answers
58 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
1k 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
345 views

QGis Zonal Statistics Plugin NoData included in Calculations

I have been trying to use the QGIS zonal statistics plugin. My raster has a nodata value of -99999 and all other values are positive. After computing the mean zonal statistics there are a number of ...
4
votes
0answers
99 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
1answer
849 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) ...
3
votes
2answers
229 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
621 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 ...
3
votes
2answers
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 ...
3
votes
1answer
241 views

How to apply a color gradient to a shapefile from QGIS console?

Anyone knows how to do a color gradient from the console to a shape file in Qgis (orin Python)? Like the image below.
3
votes
1answer
556 views

How to generate a grid programmatically in Python without GUI?

Is there a QGIS Python binding for generating a grid programmatically without using the GUI?
3
votes
1answer
227 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 ...
3
votes
3answers
1k views

QGIS 2 Python error on Mac OSX

Have just installed newly released QGIS 2.0. I installed the gdal package available at the official kyngchaos site. It seems to run ok, but when the program loads up I get a lengthy error message ...
3
votes
1answer
1k 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
1answer
1k views

How can I add button to the QGIS toolbox or create my own toolbox?

I want to create a button and add it to the QGIS toolbox or alternatively create my own toolbox and add the button here. A plugin should be started when the user clicks the button.
3
votes
1answer
1k views

How to use gdal_contour in QGIS Python console?

Is there a way to use the gdal_contour utility with-in the python console of qgis ? Thank you
3
votes
3answers
76 views

Drawing some points in QGIS 2.4 using Python

I'm new to PyQGIS so here goes: Give a new QGIS project, how can we draw some Points on the map? I tried the following but nothing showed up. Should they be placed in a Vector layer before they can ...
3
votes
1answer
912 views

How to find the nearest line to a point in QGIS? [duplicate]

My question is that given a point and few lines, how should I go about finding the nearest line to the point? I am aware of How to I find the nearest line to a point?, but that isin ArcGIS and ...
3
votes
1answer
368 views

Is it possible to programmatically add calculated fields?

In the Memory provider described in PyQGIS Cookbook or in question How to create a new empty vector layer programmatically? I can see how to create a vector layer programmatically using standard ...
3
votes
1answer
60 views

QgsMapCanvas.reresh() does not reload new wfs layer features, but panning does

I have a wfs layer loaded in a standalone QGIS app, which I am updating by running a database query on the view it is based on. The feature is added with no problems and I reload the layer with: # ...
3
votes
1answer
202 views

Looking for help for automatically making a QGIS map

Im looking at making a standalone script, that on execution will run the QGis MapComposer using a previously generated template and output a PDF/PNG of the map. This process of making a map will be ...
3
votes
1answer
624 views

Joining table to shapefile with pyQGIS

Joining shapefiles is a relatively straightforward proess in QGIS using 'add vector join' in the layer properties menu. I can add a csv file as a vector layer, as well as a shapefile, and join the two ...
3
votes
1answer
376 views

How to calculate all paired shortest path using PyQGIS?

The code for shortest path analysis with PyQGIS specifies start and end nodes explicitly: pStart = QgsPoint( -1.37144, 0.543836 ) pStop = QgsPoint( -1.1027, 0.699986 ) ...
3
votes
2answers
1k views

PyQgis overwrite shape file and adding layer to Qgis

I am creating a shapefile in python by: driver = ogr.GetDriverByName('ESRI Shapefile') datasource = driver.CreateDataSource('c:/temp/toke2.shp') layer = ...
3
votes
2answers
188 views

Merging polygons at county level to state level

I have a shapefile that represents counties (admin 2) only, but I need to create a state level (admin 1) polygon file (I'm using QGIS). I will need to sum up (or average) the relevant data at each ...
3
votes
1answer
673 views

Changing attribute data types using PyQGIS

OK, so I've already asked a question how to access attribute data types when developing plugin for QGIS, using PyQGIS. And one helpful member said i should use pendingFields() method on the current ...
3
votes
1answer
319 views

QGIS python - identify and highlight features programatically

In QGIS there is an option to select features of a selected layer using a "identify feature" tool. Then the feature get highlighted in a different color and attribute dialog is poping up. like that i ...
3
votes
1answer
45 views

How to store the CHANGES to a map database

I'm looking into providing a map amendment service for a particular map series. The service will help map owners look into the changes made to the operational features of the map, after the map was ...
3
votes
1answer
159 views

Get features in order they are selected using QGIS

Is there a way of establishing the order that a user selected features using QGIS and Python? By example: we have a network of line features representing a road network, and the user defines a route ...
3
votes
1answer
557 views

Getting dataProvider from vector layer outside QGIS

I'm using PyScripter to explore PyQGIS API because of it's very handy auto-completion function. I've managed to get a handle on a PostGis vector layer by: >>> from qgis.core import * ...
3
votes
1answer
147 views

Button to add a new line in a non-spatial table without opening the table itself using QGIS?

While using QGIS and having loaded a non spatial table (from PostGIS), is it possible to add a new row to its table attributes without having to open the attribute table first as in here Is it ...
3
votes
1answer
471 views

Why are the features in my memory layer not displayed?

I am trying to create a memory layer, I followed the directions from the page below but no points appeared on my map. First I tried typing each line into the python console and I also create a plugin ...
3
votes
1answer
326 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 = ...
3
votes
2answers
158 views

How can I read the settings for the QgsPaperItem from XML?

I saved a template qpt for the map composer and now I want to read all the settings. I am able to insert the items with composition.addItemsfromXML... But this doesn't load the settings for the ...
3
votes
2answers
55 views

PyQGIS: Speed up for adding features and attribute arrays?

Context: I'm writing a dynamic import tool for QGIS (2.2 to 2.5) with python. Datatype: Binary Datasets with environmental simulations from HPC which might contain millions of features and terabytes ...
3
votes
1answer
53 views

PyQGIS esri ascii grid to .bil conversion

Esri ASCII GRID can be converted to esri .bil format by following way in a desktop From QGIS desktop menu-->Raster-->conversion-->Translate(convert format) How can I write a python code because I have ...