Python is an open source interpreted programming language used in many GIS programs.

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PyQGIS: Properly trigger actionPan() tool when feature is added

I wrote a plugin which creates a custom map tool that adds features. I would like to cleanly connect to the pan tool after a feature is added. I've done it in the following way and it works, but I get ...
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234 views

Cumulative field calculation using Python in ArcGIS for Desktop?

I am using the following Python code to sum cumulatively but I need the summation to take place while the other field is equal to 1 and then again start the summation when it's equal to 2. I need the ...
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135 views

Finding areas with high POINT density from PostGIS table using Python

I have a PostGIS table with thousands of POINT objects and I want to find areas that have a high density of points. I have the DBSCAN clustering algorithm implemented in Python which does exactly ...
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107 views

QGIS processing framework SAGA NaturalNeighbor in external Python Script - No Output

I want to build a little script, which generates a NaturalNeighbor grid based on a point Shapefile. The script runs within my PyDev environment without any error messages, but no outputfile is ...
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42 views

Setting up ArcPad applet (Python) that calls arcgisscripting?

I've been asked to support a legacy script that was "made" (read: found) by a former coworker. My python skills are pretty basic, so I went right to installing the applet like I would for a VBS ...
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36 views

Python Script calling custom model failing during model execution

I have a python script that calls a model I built in model builder. If I run the model by itself it runs perfectly. If I call the model in the python script, the model errors in various locations. ...
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112 views

Orthographic projection in Python Basemap

I'm trying to plot a GeoTIFF in Python using Basemap. I can do so correctly with cyl projection like this: m = Basemap(projection='cyl', llcrnrlat=LL[1], urcrnrlat=UR[1], ...
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57 views

How to write in only a file .csv (or .txt) the values contained in several rasters?

I am an beginner in Python programming but I would like to write in only a file .csv (or .txt) the values contained in several rasters. For example, I built several rasters by using a loop. The ...
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46 views

GeoDjango WebMapping Application Update

According to the below GIS.SE questions, GeoDjango was the preferred framework for creating simple and quick webmap applications. But these questions are now all 2-3 years old. Can we verify whether ...
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54 views

How to load style from postgresql?

Is there any way to load a postgresql style for a vector layer using python? There is a function: loadNamedStyleFromDb (const QString &db, const QString &theURI, QString &qml).Does it ...
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28 views

Problem Loading Plug-Ins in QGIS 2.2 on Mac

I'm trying to load the 'processing' module in QGIS (2.2.0-Valmiera on Mac OSX 10.8). However, this module and others (e.g. GarminaCustomMap) re failing to load with a message: ImportError: No ...
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57 views

Mapping from one plane on the other plane despite of masking regions

have a set of data given here, where in the first and second columns there are the sky coordinates (ra,dec) e.g. right ascension and declination, respectively and in the third and forth, the ...
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74 views

Creating symbology by category in python?

I'm trying to create a python script that creates color-coded symbology by county for multiple maps with different data. I've never created a layer file for the purposes of symbology before, but I ...
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47 views

Clipping between features within a single vector?

Is it possible (via the Qgis API and friends), to clip polygonal features within a single vector layer? The hope is to accomplish this without having to duplicate the feature into a new layer. ...
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56 views

Scaling features based on an attribute

I would like to scale polygon features by a specific factor I have calculated for each feature in a feature class. I know of the Scale tool, however it only allows for manual entry of a scale factor ...
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206 views

QGIS plugins - how to use a custom behaviour on right click and actionPan on left click?

I have been struggling with this problem for quite a long time. Here we go : I implemented a maptool that draws a red cross on the point that is being right-clicked on. There are good how-tos, such ...
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125 views

pyQGIS 2.0: Sending signal when identify button is pressed via gui

I have a question regarding the qgis identify tool for version 2.0. I would like to know if it's possible to send a signal when the actionIdentify is triggered by the user via the gui. I'm trying to ...
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16 views

Proper updating of new memory layer geometry?

Current workflow for a toolbar button: -create memory layer -save memory layer to shapefile Then the user uses the built-in QGIS tools to add geometry and finally saves changes via the auto prompt ...
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88 views

QGIS2.4.0: Cannot import qgis module in python “from qgis._core import * \n DLL Load Error”

Having some trouble importing qgis into python. I'm very new to python so it could be a simple mistake. The path seems to be correct. It gets this far: File "<stdin>", line 1, in ...
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69 views

Vector layers without geometry in QGIS?

Using QGIS, I have set up a couple of automated layer additions via the toolbar. After adding geometry in each respective layer (point, lineString, polygon) and saving changes to the layers, the added ...
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180 views

Rendering points and polygons with Mapnik

I've tried to render a few maps in Mapnik and I have a little problem. I want to render a map that contains two layers: point and polygon. I've used this script: import mapnik rule = mapnik.Rule() ...
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29 views

Vector Layer Symbol (ism) properties?

I would like to streamline the render of a polygon grid vector layer as a simple line (no fill) via Python coding. I am I bit confused by the implementation referenced by the API. Is it possible to ...
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68 views

how to call the method of DescribeFeatureType in owslib

I want to execute DescribeFeatureType operation of wfs services. However, I can’t find the method to fulfill this operation in the owslib. Can anyone kind enough to tell me how to do this. The ...
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115 views

How to make crs transformation of a QgsVectorLayer?

I need to transform QgsVectorLayers in python from one crs into another crs. By googling I found the following solution ...
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47 views

How to programmatically interrupt QGIS initialization and startup

I'm wondering how to interrupt the initialization of QGIS 2.0 on Windows XP before start up. I've put a dialog in one of my plugins that shows up on start up. However, I'd like to make a quit button ...
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331 views

Python comtypes and ArcObjects: Snippets GetApp() fails at 10.2

I have been experimenting with Python's comtypes module to access ArcObjects. We are still using ArcGIS 10.0 as we are in the process of upgrading our ArcGIS for Server to version 10.2.2. I am ...
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45 views

How to go about creating a custom tool/adding special functionality for a web app

In my soon to be developed web app, I will have an image service and also a feature service that is essentially an index to the image service, with all kinds of attributes. I would like for the user ...
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128 views

PyQGIS: Editable Combobox for Value Map widget isses

I am having issues with an editable combo box in QGIS 2.4. The edit widget is set to Value Map with an uploaded CSV. However, if a new values (not included in the key value pair list) is added, the ...
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155 views

Import QGIS Python modules in Python command line or standalone script

I am running a Windows 7 machine with Python version 2.7.8 (32 bit). I installed QGIS 2.4 (Chugiak) from OSGeo4W and simply want to be able to import the QGIS Python modules (e.g. qgis.core) into ...
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36 views

Link to pdf file through mouse clicking

I need help in identifying the feature attributes displaying a pdf file when click in that feature. I see many examples but I don't have success. I try this code: command = "firefox"; imagerelpath = ...
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111 views

Using python libary simplejson and urllib in PostGIS

I installed PostGreSQL9.3 and want to create a Pl/Python function using simplejson library and urllib. First I use OSGeo4W Shell to test the similar python script, it works. Then in PostgreSQL, it ...
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102 views

How to write a custom map canvas item by subclassing QObject and QgsMapCanvasItem?

I'm writing a QGIS python plugin where I place some QgsVertexMarkers on the canvas like this: marker = QgsVertexMarker(self.canvas) marker.setCenter(QgsPoint(point[0],point[1])) Now i would like ...
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86 views

Python code to determine the position on a map using Geo-Tagging

What is a proper python code, which enables to scan photographs (when captured from a series of snapshots) and match it with a geo-tagged image database. Based on the extent of similarities existing ...
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71 views

Doesn’t cal AGSSOM program to manage AGS mapservices from python script

We are using ArcGISServer 10.0 on a windows server. Because of database management we need to stop several ArcGISServer Services. For this purpose I use the AGSSOM program, which is called from the ...
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35 views

GRASS r.out.mat memory issues

we have built a model with pythn/GRASS that calls the r.out.mat module. The area is quite large 25,000x25,000 cells. The machine we are running it on is Windows 7 machine with 16GB of RAM. After a ...
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142 views

pyQGIS (Spatial Join): Sum features of attribute from point layer and join with vector layer

I am new to Python and QGIS. I have avoided asking questions up to now. But by now I have developed a reasonable idea of where i want to go so and where I am stuck. So, I have decided to ask but sorry ...
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98 views

Python error message after download (QGIS 1.8.0/ Windows 7)

Hello to all members of the forum, I downloaded from the OSM website a small area in the neighborhood of Strasbourg, France: X (longitude): 7.6808 7.8216 Y (latitude): 48.5075 48.52 I got the two ...
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120 views

How to keep all the unique columns of the shapefiles after merge?

Writing a script where the user is asked to select a directory which contains Folder_1 and Folder_2, both containing shapefiles and run various algorithms. The basic logical process of the script is: ...
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40 views

ExtractByMask with one mask and multiple layers ArcMap

I have a multiple cost distance rasters and multiple feature layers. I need to find and join the feature layers (or associated shapefiles) that lie within a threshold of costs on the cost rasters. For ...
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894 views

How do I install PyProj module for Python 2.7 on Windows 7?

I am having trouble installing the pyproj module for Python 2.7 on Windows 7. I have tried both the 32 and 64 bit installers from this list but the install crashes each time I run it. I have the ...
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166 views

Using qgis modules in standalone application with PySide?

I want to make small standalone application using PySide and QGIS python modules to display satellite images and do standard GIS operations, like creating new shape file and placing polygons or points ...
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83 views

Disable customized context menu for some cases using python

I create a python add-in tool to add new item to the context menu, but I want the new item enabled only when user right click on map when within a buffer of polyline feature. I haven't figure out how ...
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58 views

How to export the legend (Layers Panel) as an image in QGIS using the Python console?

I want to export the Legend (the Layers Panel) as an image using the python console.
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833 views

How can I get all the latitude, longitude coordinates/points inside a rectangular polygon drawn in google maps?

Google maps lets you obtain a valid address by clicking on houses or buildings one by one, but it would be much easier if you could draw a polygon on the map and get a list of all valid addresses ...
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144 views

QGIS 2.2.0 GRASS not worked

I use QGIS 2.2.0 on Windows 8 64 bit. I try to install use Standalone installer and OSGeo4W and still get the error And then i start GRASS C:\Program Files (x86)\GRASS 6.4.2>grass64 ╬╪╚┴╩└: ...
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48 views

Is is possible to run the QGIS python module server side?

I'm pretty new to programming but I want to use the QGIS python module on a server. Basically I am trying to create a JPEG map programatically on a server. I already have a python script to create ...
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80 views

Highlight paths between two points

I'm new to qgis and very sorry if this is a simple question to ask. IS there a way to highlight the available paths (roads) between two selected points in a road map(in qgis) ? I want to find the ...
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64 views

QGIS API changes from 2.0 to 2.2

I have the same program running on two different machine, one with Qgis 2.0 and the other Qgis 2.2. The machine running 2.2 doesn't seem to render the map canvas. I thought it was how I has creating ...
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47 views

Running algorithm from Processing takes much much longer time than doing it from Qgis GUI

I have a road layer with 32000 features, and I want to find all the intersections. when I use processing->SAGA -> convert polygon/line vertices to points, it is all done in less than 5 seconds. ...
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117 views

Batch Zonal Statistics to Spreadsheets?

I have a pretty immense amount of Zonal Statistics as Table computations to do, and would love to find a way to grab mean and variance values from the little .dbf tables ArcGIS creates and put them ...