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

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Adding features in the layer with reference to another layer

I have built a tool for creating line in the exact center of two selected lines through this code: import math def mainCl(): ftr_geom = [] select = iface.activeLayer().selectedFeatures() ...
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69 views

Esri Python Toolbox(pyt) corruption in ArcToolbox.dat

Symptoms: Open ArcCatalog and all tools within Python Toolbox(pyt) have a red-x error next to them claiming that "Arcpy module has no attribute Parameter" Close ArcCatalog Delete ArcToolbox.dat file ...
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32 views

Can I invoke MapWindow GIS software from python,.net or any other scripts language

I am interested in working with MapWindow GIS. Is it possible to invoke MapWindow GIS from scripting (like external python).
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39 views

Error writing defaultdict values to feature class rows

I originally posted building dictionary from feature class field values, how can I ensure there are no duplicate values per key. The goal is to update another field with all the values per key, which ...
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60 views

Python trainings comparison

My employer provides me with a generous annual training budget and I'd like to use it on one of the following two Python courses. As a GIScientist, I would like to attend the course which will give ...
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83 views

How to change color ramp in graduated classification with standard deviation using pyqgis

I'm using graduated clasiffication with standard deviation to style my shapefile (see code below). But I need to use different color ramp for classes below mean (-1std, -2std etc.).I'm thinking of ...
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19 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 ...
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48 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 ...
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60 views

Is there a python function in QGIS to detect if the output file is saved to the hard disk?

I'm currently using QGIS 2.4 and writing some custom scripts on it. A proper script not only accomplishes its function, but also accepts user defined parameters and checks for possibilities of errors. ...
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61 views

User input and passing variables with ModelBuilder

I have created three modelbuilder tools that must be run in sequence. After running each tool, the user must examine several shapefiles and potentially change the input parameters of the next tool. ...
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42 views

Stereo-pair Image Registration

Is there a simple command line or python based way to visually register a pair of overlapping stereo images and clip the non-overlapping areas out? These images do not have spatial information ...
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33 views

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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127 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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69 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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66 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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31 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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28 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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74 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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40 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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37 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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51 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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26 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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44 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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59 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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42 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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47 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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85 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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14 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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57 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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53 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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116 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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22 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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55 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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82 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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43 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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262 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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111 views

ArcPy Multiprocessing 000714 - Working in Debug Mode

In an attempt to render an interactive window via matplotlib I am using an out of process script in a toolbox. If I debug the script, it is possible to step through and render the window as expected. ...
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44 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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100 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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95 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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33 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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74 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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57 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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58 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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54 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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30 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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109 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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80 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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91 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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37 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 ...