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

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How to transfer the attributes of features based on their spatial relationship?

I'd like to check if a point feature class is placed on a line feature using python in ArcGIS 10.0. I have created a set of point features and placed them directly on a group of line features at ...
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2answers
442 views

How to determine the coordinates of the corners of the raster layer

How can we determine the coordinates of the corners of the raster layer? The image opens function QgsRasterLayer.
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2answers
166 views

How to interact layers with a nested loop?

I've dealing with the code below with such a long time. I have to show in a raster image the result of calculating the cost of the electricity for a solar plant. The thing is that I have to interact a ...
2
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1answer
526 views

Compare two Digital Elevation Model (DEM)

I would like to know what's the best method(s) to compare two DEMs without using any GUI soft like QGIS or ArcGIS. I'd like to do it in Python or C++, with GDAL or other similar lib. Does calculating ...
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3answers
2k views

Updating Attributes using Pyshp

Is it possible to update an attribute field in a shapefile using pyshp ? I went through their documentation and all they show is how to create new attribute rather than editing or updating an already ...
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2answers
464 views

Moran's I z-score in ArcPy

I have a ArcPy script to calculate Moran's I several times (50 to be precise). However, I am not interested in the Moran's I value, what I need is the z-score returned by the tool. Even though the ...
4
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1answer
147 views

How to return text from GP service?

So I've got a website that I want to extend by letting people look up postal/zip codes for an address they enter. I've already got all the addresses (with their postal codes) for the city in an ...
2
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2answers
390 views

Weird File Path Returning from Print Statement Causing ERROR 000732

I have created a python script in ArcGIS 10.1. My first parameter type is a 'Feature Layer' set to as a multivalue input. I was running my script quite well off of data from one of my drives (my ...
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0answers
476 views

Extracting x,y,z values from a postgis linestring to python using ogr

I am trying to load a postgis linestring into python (using ST_DumpPoints) and extracting x,y,z coordinates, which is working but extremely slow..and if i mean slow, i really mean it (yes, it takes ...
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0answers
707 views

How to calculate average value within a polygon(in Qgis with Python)?

Now I have a point and polygon shapefile and I want to calculate the points' average value within each polygons How to do it with python? I tried to find out but google gives me a lot of raster ...
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1answer
139 views

How to save ArcGIS process output to variable?

I've created script in Python for ArcGIS that simplify Line, and make buffer from processed line. input = "input.shp" name = "bord" buffer = "buffer.shp" gp.SimplifyLine_management(name, input, ...
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1answer
193 views

How to save python session in QGIS?

After running a lot of scripts in QGIS' python console, I have more than 10 dictionaries and lists, and I need these for further analysis. Is there a way to save python session, with all these ...
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4answers
4k views

Possible to add multiple fields in single arcpy statement?

I'm trying to add multiple fields to a table using arcpy and am wondering if it's possible to have multiple fields declared in the AddField management, and their values, separated by commas or ...
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1answer
192 views

How to save image to disk with with gdal_translate?

I do: import os from gdal import * filename = 'c:/rast.jpg' outputTif = 'c:/rastOut.tif' os.system('gdal_translate filename outputTif') but it returns "1". gdal_translate doesn't save the image ...
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1answer
414 views

How to add MS SQL table using python console?

I have MS SQL Server 2008 R2 database. How to add MS SQL Table using python console in QGIS?
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1answer
282 views

OWSLib and python3

Trying to install OWSlib-master (and 0.7.1) from https://github.com/geopython/OWSLib yields problems that ultimately seem to be related to python3 >c:\Python32\python.exe setup.py install running ...
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1answer
1k views

qgis plugin: “WindowsError: [Error 6] The handle is invalid”

OS: Windows 7 64bit GIS: QGIS 1.8 (qgis.org/downloads/QGIS-OSGeo4W-1.8.0-2-Setup.exe) path variable: GISBASE=C:\Program Files (x86)\Quantum GIS Lisboa\apps\grass\grass-6.4.3RC2 ...
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0answers
299 views

Field calculator error [duplicate]

NOTE: This problem is similar to one that was answered here: Why does Field Calculator return 0 values when decimals are expected? I'm relatively new to python, and am trying to run a simple field ...
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1answer
417 views

Using the API of QSpatiaLite plugin

I am using the popular QSpatiaLite plugin for QGIS. Since I am creating and modifying SpatiaLite tables directly with Python (using pyspatialite), I wonder whether I can automate tasks such as ...
3
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3answers
3k views

SearchCursor() fails to read feature class

First of all, I would like to apologize if this problem is trivial for you guys since I am very new to ArcPy and Python in general. I want write a script to read attribute table from a feature class ...
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2answers
349 views

How to handle adding a PostGIS layer in pyQgis without saving password?

I'm writing python plugin and trying to find the right way to add PostGIS layer on the map without storing user password. After adding layer on the map, I strip out the password from uri like this: ...
3
votes
1answer
488 views

Finding optimal network with python and network analyst in arcgis 10.0

Hello GIS StackExchange, I'd like to know if there's any way to find the shortest distance across the diagonals of a polygon. I am creating a network analyst solution to determine the most cost ...
10
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1answer
912 views

How to address the new “Task-Completed” QgsMessageBar in Python?

I am really amazed what huge steps the QGIS development has taken in the last months. The new iconset, the improved Print composer and many more changes to be seen in QGIS 2.0 are really awesome! ...
2
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1answer
208 views

Script to either rotate existing text element or insert graphic element

I have about 300 maps that contain a text element that needs to be rotated. I am pretty new to python but I have heard how great it is. This seemed like the perfect task for python but I have had no ...
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0answers
69 views

Replace Null Values Field Calculator [duplicate]

I am using ArcGIS 10 and have a polygon shapefile in which many of the numeric fields are Null. The polygon shapefile in question is produced by joining a polygon shapefile with a point shapefile and ...
3
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1answer
849 views

How to add one or more points to an existing polyline or polygon?

Using the following code, I make a polyline with two points. vl = QgsVectorLayer("LineString", layerName, "memory") pr = vl.dataProvider() vl.startEditing() fet = QgsFeature() ...
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1answer
3k views

Python GDAL: Write new raster using projection from old

If I read in a raster image as an array, then make some changes to the values in the array, how do I then save the array as a raster with the same projection information as the original array? In ...
3
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2answers
2k views

Merging many rasters using Python

I have a list of many many rasters. I want to have a simple and easy to understand script that takes this and merges it into one big mosaic. I found a similar question but the accepted answer adivices ...
2
votes
1answer
525 views

Am I over-complicating adding and then calculating fields? Suggestions for a better way? (Python)

I'm attempting to re-position a question I asked yesterday here. I am starting to think that the way I wrote my code just isn't the best way. Am I overcomplicating things? I know for a fact that ...
4
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1answer
379 views

Arcobjects: DisplayTransformation.FromMapPoint() transforms wrong

I want to transform map coords into page coords in ArcObjects in Python. So I do, say: >>> pApp = NewObj(esriFrame.AppROT, esriFrame.IAppROT).Item(0) >>> pDoc = pApp.Document ...
2
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1answer
167 views

How to save after using fet.setFeatureId in pyQGIS?

By using the following code, I want to change the id of the line when saving the line. But the setFeatureId command, gives a false when doing the commitChanges(). Any idea how to change the id? vl = ...
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2answers
344 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 ...
2
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1answer
2k views

Incorrect field name resulted in RuntimeError: ERROR 999999 (Also, better code for adding and calculating fields)

This is the bottom half of my code (and it's been edited somewhat to share publicly). The code works perfectly fine when the fieldList has only three fields in it, but when I populate it with all 108 ...
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1answer
608 views

How to store selected attributes of vector layer using PyQGIS

I'm following this PyQgis workshop: http://www.qgisworkshop.org/html/workshop/python_in_qgis_tutorial2.html#accessing-data-attributes I have a point layer shapefile. I want to be able to retrieve and ...
2
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2answers
218 views

How to create a line from more than two points?

I have a loop which calculates two points for each iteration (x3,y3) and (x4,y4). As seen in the code these two points are added for each iteration, which gives i-1 lines. Each line has a individual ...
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2answers
1k views

How to clip raster by multiple polygons in multi rasters?

Using QGIS, I want to clip a raster by multiple polygons contained in a single shapefile. I read that gdalwarp can clip my raster by multiple polygons BUT the output is a single merged clipped raster. ...
6
votes
2answers
1k views

Is there a way to call the clip function in pyQGIS from the python console?

Is there a way to call the clip function in QQGIS from the python console? It is found under geoprocessing tools in the vector menu.
3
votes
2answers
3k views

How to add a column in QGIS via python

I have a point shapefile and a polygon shapefile in QGIS now I want to use the point shapefile's value add to polygon shapfile(be a column in the end) there are colors with each value and make the ...
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votes
1answer
667 views

Teaching Python to Land Surveyors

Does anyone have any good examples of using Python to automate or simplify common surveying tasks? I'm teaching a Python/ArcPy lab this week for a GIS class. There are a number of surveying ...
13
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1answer
1k views

How can I utilize NumPy arrays to optimize big data geoprocessing?

I'm interested in learning how to utilize NumPy arrays to optimize geoprocessing. Much of my work involves "big data", where geoprocessing often takes days to accomplish certain tasks. Needless to ...
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1answer
221 views

How to write Process Dialog log information to text file in ArcGIS?

I have created a custom model. When this model is run, it shows a process dialog which has some log information. I want to write that log information into the text file for further analysis. Does ...
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1answer
271 views

using ZonalStatisticsAsTable in python script

I use a python script in which the function ZonalStatisticsAsTable is called. In ArcGIS9.3 it all worked fine. Our company just went to ArcGIS 10.1 and now it doesn't work anymore. When looking ...
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votes
2answers
419 views

Need help assigning values to field using OGR in python

I've got a similar question to this one How to programatically populate a shapefile field with polygon areas in OGR?, but the solution doesn't seem to be working for me. I am trying to import a ...
2
votes
1answer
529 views

Calculate field result is float with Arc tool, integer with arcpy script

I am trying to calculate a field for some points within a python script using arcpy functions. (This is calculating the percentage visibility from a cumulative viewshed, if that matters.) # Process: ...
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1answer
292 views

How to calculate smallcircle on sphere

I use this python code to calculate a greatcircle: https://code.google.com/p/pyroms/source/browse/trunk/pyroms/greatcircle.py?r=39 After initializing the greatcircle I can calculate points on the ...
2
votes
1answer
523 views

View HTML field data with QT4 browers as a QGIS Run Feature Action Tool

I've successfully populated a sqlite table with an HTML-encoded-table as a field attribute, and so there is literally a Table within a single field value in sqlite, for each record. This is going to ...
3
votes
1answer
3k views

How to change vector attributes values?

I want to change vector attributes values. i could not get the command fet.setAttribute indeed, it is mentionned in http://hub.qgis.org/issues/7223 that: "The QgsFeature instance now must be ...
4
votes
2answers
2k 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 = ...
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0answers
216 views

Help in GRASS/QGIS/Python

I have Idea about ArcGIS, and a bit of QGIS and zero programming knowledge, which I am trying for thesedays. I saw GRASS GIS and have started working with shapefiles, which are not being loaded... :( ...
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votes
2answers
297 views

How do I tell GRASS where to find Python?

For some reason, when I start GRASS on my Mac it says that it has found Python 2.6.7. However, /usr/bin/python version is 2.7.2 and I can't find a lower version anywhere on my system. Potentially ...