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

learn more… | top users | synonyms

2
votes
1answer
552 views

How to determine area of pixel in meters with GDAL and Python?

I have a raster loaded in Python using GDAL bindings. I'd like to be able to determine the area of a pixel in meters although I'm not confident that the projection is in meters. On this page I see a ...
3
votes
2answers
1k views

Unzip a file using python caller in FME 2011

The idea is to download a zipped file from a website and unzip it using FME 2011. I have attached a screenshot of FME workbench which is not working. Any help is greatly appreciated. Thanks. Sam
3
votes
2answers
2k views

How to write a SQL WHERE Clause using Multiple Choice values in FME?

I published a parameter which is of Choice Multiple type. I wish to use values from this parameter for WHERE Clause when Reading Inputed Data in the begin of Workbench. So there is no problem if I ...
2
votes
1answer
631 views

Running C# code from Python tool for ArcMap?

It appears that the only way to copy individual rows of data while preserving GlobalIDs in code is by using C# or VB.NET. I need to run the C# code from the above link within a python tool, and I am ...
6
votes
1answer
840 views

Mapnik/Python Compatibility

Anyone know what versions of Python Mapnik is compatible with? I'm having trouble getting Mapnik to work. I'm thinking it might be because I am on 64-bit Win 7 and installed the 64-bit Python (v2.7) ...
10
votes
3answers
801 views

How to download and process raster files in Python?

I am fairly new to python and seek guidance for a question which might sound trivial to many. Is there a way to use 'wget' in a python script to download raster files from a server and process them ...
3
votes
1answer
535 views

Want to use GDAL in Arc10 toolbox via subprocess call

I'm attempting to launch a version Python 2.5 that supports GDAL from an ArcGIS10 toolbox script. I'm doing this because I'm having loads of trouble importing the GDAL library directly into Arc, and ...
5
votes
2answers
3k views

GDAL Python bindings not picking up OGR PostgreSQL driver

I have a windows server (Microsoft Windows Server 2003) with: Python 2.7, PostgreSQL 9.04-1, GDAL 1.8.1 (installed from the windows installer (gdal-18-1500-core.msi) hosted at ...
3
votes
1answer
2k views

How do I 'select' using ArcPy?

When using a cursor to loop through an attribute table, is it possible to iteratively select each row? I want to clip a line to a polygon grid (see previous question); due to the size of the grid the ...
4
votes
2answers
1k views

How to merge street layers in QGIS for exporting to PostGIS?

Is there any way of merging lots of street data in QGIS and getting one layer for exporting it to Postgresql? I know one method using mmqgis "Merge Layer" tool. It works in Ubuntu but not in ...
0
votes
1answer
2k views

How to solve an installation problem involving QGIS, Python, and a plug-in?

In an attempt to get the plugin "Profile Tool" working, I installed geoslib and python Shapely 1.2.10 module as requested using following: sudo port install geos Then install Shapely once ...
2
votes
2answers
864 views

How to translate (reposition) a raster in Python?

I tried to use QGIS GeoReferencer to translate a raster layer, but somehow failed. It just goes to somewhere unexpected. Now I decide to do it myself, with python. I think some libraries like GDAL ...
5
votes
2answers
341 views

Finding Raster Overlap within a Directory

Here is the scenario: I have a directory with 100+ map projected, single band, rasters that weighs in a 40GB+. I have used ArcMap's built-in mosaicing tools to create a raster mosaic. I am using a ...
6
votes
5answers
2k views

Python, shapely library: is it possible to do an affine operation on shape polygon?

I am trying to create a rotated rectangle in lat/lon coordinates. Basically, I have the coordinates of the center and rotation angle around the center. Is it possible to do using, shapely or gdal, ...
6
votes
5answers
12k views

How do you test for a NULL string field in the Field Calculator with Python?

I am trying to perform an operation on a string field with a condition that it contains data. Referencing None with Python does not appear to work when the field is nullable and contains <Null> ...
9
votes
3answers
6k views

How to find the locations of the highest values in a raster?

Using ArcGIS 10, I have a raster where I would like to find the pixel with the maximum value in the raster and return its location (center of pixel) in decimal degrees. I would like to iterate through ...
5
votes
4answers
2k views

Does File Geodatabase performance degrade as it fills up?

I'm having a memory leak issue. Upon investigating this more, it seems the file based geodatabase I write to in a loop, is growing very large, and as it grows, it significantly degrades the ...
0
votes
4answers
606 views

How to unproject a shapefile in Python?

I have one shapefile with XY coordinates in meters. Now, I want to develop one script in Python which converts meters to decimal degrees. Please help me to develop this. Thanks
8
votes
3answers
5k views

Setting parameters in Script Tool using Python?

I hate to bug you all with the same problem over and over again but I run into a new problem everytime I make a slight change to the code. All I did to the code below was to replace field names to ...
9
votes
3answers
1k views

Use Esri Geoservices REST as backend for Python web framework (Django?)

I would like to know if it's feasible to use an existing Python web framework such as Django/GeoDjango as a frontend to work with Esri's Geoservices REST API? I envision developing a database engine ...
3
votes
1answer
567 views

Adding Descriptions to custom ArcToolbox 9.3.1

I looked http://webhelp.esri.com/arcgiSDEsktop/9.3/index.cfm?TopicName=Setting_script_tool_parameters and couldn't find how to add Descriptions for each parameter in the script tool. I see how to add ...
7
votes
1answer
258 views

Efficient Network Neighbors?

I would like to identify the Kth order neighbors of an edge on a network, specifically the neighbors of a large set of streets. For example, I have a street that I'm interested in looking at, call ...
1
vote
1answer
348 views

How to tranform a column field into a list using Field Calculator

I'm trying to make a simple field calculation with ArcGIS 9.3: New field = Old field - Old field(first value) which in Calculate Field with python code should be Expression: !Old field! - first ...
4
votes
3answers
6k views

ArcGIS 10/arcpy: Help needed with syntax for CalculateField_management in Python script

I need to use CalculateField_management in a Python script, and the calc expression needs to concatenate a runtime variable, a string, and a field (string) value. I have searched all over for ...
1
vote
0answers
260 views

arcgis server 10, vb.net, non pooled service, web adf

i am running arcgis server 10. i created a A.MXD file, then started arcgis server and successfully added non-pooled service using A.MXD. i also installed visual web developer 2010 express and created ...
2
votes
1answer
193 views

ArcGIS 10 SP2 issue with AggregatePoints

Esri persuaded us to upgrade to SP2 and now we cannot use the code we have, as it doesn't work. According to the download material, NIM063853 is when AggregatePoints doesn't create the derived ...
9
votes
2answers
1k views

ArcMap running scripts slower if you import Arcpy

I am finding ArcMap runs slower, if you have written a script, which imports arcpy. You may wish to write a script that can be operated in ArcMap, through the python window, or as a standalone ...
2
votes
0answers
256 views

RT Sql Layer plugin giving an error [closed]

I am trying to use the aforementioned plugin with QGIS 1.7 and Postgres 9.0/PostGIS 1.5. Added a PostGIS spatial layer w/out a problem and then clicked on the RT Sql layer button which displayed the ...
3
votes
1answer
2k views

How to update only a single vector layer in QGIS map canvas?

I want to update a single vector layer as I am working on 8 vector layers and they are getting fast data from serial port so for updating I use mapCanvas().refresh() which refresh all the layer and I ...
3
votes
2answers
756 views

PostGIS + pgRouting: Adding dummy links to a road network and performing routing analysis

I'm a beginner when it comes to postgis and pgrouting development. For a project I'm working on and a bit of the algorithm: I have a polygon layer that represents zones I have a line layer that ...
2
votes
0answers
1k views

Perfectly running python script gives error when run from web.py

I have the following python script which runs perfectly if run separately: import arcpy val = arcpy.GetCellValue_management("D:\dem-merged\lidar_wsg84", "-95.090174910630012 29.973962146120652", ...
4
votes
2answers
864 views

arcgis 10, python update raster of mxd file

i wanted to update the raster file in a mxd file using python. for example, i created a.mxd which contains b.tif file in it. now, i obtained c.tif and want to update the a.mxd, i.e. want to delete ...
3
votes
2answers
5k views

Loop through records

I have written a python script that is supposed to basically loop through selected records of a feature class. Here's a sample of what a table looks like: OBID STID FL TL 1 1 0 9 ...
7
votes
1answer
243 views

Optimize GEOSGeometry's spatial operations by avoiding thread-safety checks

A ranking algorithm I'm developing for a Django webapp requires performing spatial operations (within, intersections, sym_difference, etc.) using a query against large number of geometry objects. ...
1
vote
4answers
2k views

Install other python distributions [e.g. Python(x,y)] on top of ArcGIS installation ?

I'm using ArcGIS 10 and would like to use various additional libraries that are not included in the delivered version of ArcGIS (esp. numpy and matplotlib). First I tried to install them manually as ...
11
votes
1answer
3k views

Polygon overlay with Shapely

I'm trying to capture all the non-overlapping polygons indicated below using Shapely (given polygons A,B & C). Moreover, I'm hoping to do so without iteration, testing for intersect etc. The ...
3
votes
2answers
2k views

How to create a feature class in a file geodatabase in ArcGIS 9.3 with Python?

I'm not entirely sure if I am using the correct terminology, so I apologize in advance. What I am looking to do is create a file geodatabase and add a feature class directly into that file ...
1
vote
3answers
614 views

Replacing Variable in VB-Expression-File (.cal) of ArcGIS Desktop?

I'm trying to modify a VB-Expression saved in a cal-file by ArcGIS Desktop 9.3: dim out if [D19830701]=-9999 then out= [D19830501] else out= [D19830701] end if ...
6
votes
3answers
4k views

Insert Raster to MXD using arcpy.mapping (ArcGIS 10)

What i want to do seems simple. But again i can't even find a workaround... I have got a lot of Raster-files (ESRI-GRID) which i need to insert into a layout mxd-file and then export the map to ...
17
votes
1answer
3k views

Voronoi polygons that run out to infinity

I have been working on implementing the voronoi.py script (Bill Simon's translation of Steve Fortune's code). According to the QGIS link it is basically the same code that I am working with, but the ...
4
votes
2answers
2k views

how to create graphs while running python with ArcGIS 10

As Matplotlib seem not to work (what a drag it's such a nice tool) I'am looking for alternatives to create graphs while running python with ArcGIS 10. Besides regular pie and column charts I need in ...
4
votes
2answers
1k views

Using a bounding polygon, instead of a bounding box

I've got a large set of LAT/LON coordinates. Up until now, when I needed to select out those that fell within a certain region, I'd just create a bounding box using some MINx, MAXx, MINy, MAXy values ...
5
votes
2answers
830 views

Access to SpatiaLite .dumpshp via Python?

I'm trying to interact with a SpatiaLite database via Python on my Windows machine. I've managed to connect to the database and load the SpatiaLite extension, which means that I can pass SQL queries ...
1
vote
3answers
1k views

CreateFeatureclass_management doesn't add a layer to the TOC of ArcMap10

I created a python script for a toolbox and I am wondering about the fact that CreateFeatureclass_management doesn't add the feature-class as layer in the actual dataframe. This does not happen in the ...
1
vote
2answers
470 views

Adjust Picture Marker Symbols with Python? (ArcGIS 10 SP1)

I am working toward a map cache, and therefore have about 12 versions of the same datasets to be shown at different scales. Invariably, the symbol sizes I have set on highway shields (for example) ...
7
votes
2answers
871 views

Disambiguate messy place names in python (preferably on local machine)

I have list with several million place names that come from Flickr profiles. Users provided these placenames as free text, so they look like this: Roma, Italy Kennesaw, USA Saginaw, MI Rucker, ...
5
votes
1answer
380 views

Combined area of all features within features of another layer

I have a grid shapefile (basically, a half-degree grid of the world, where each cell has a unique id number), and a set of files with features. I want to record for each grid cell, all the areas ...
5
votes
2answers
820 views

matplotlib does not work in ArcGIS 10 and Eclipse (Python)

I have installed matplotlib (v. 1.0.1) which works with iPython quite good. But if I insert the same script in ArcGIS 10 or Eclipse 3.7.0 (with PyDev) I get always errors. As I consider to use ...
6
votes
5answers
2k views

Is there a way to disable code autocomplete in the Python window in ArcGIS 10.0

Autocomplete slows down my workflow in the Python window, especially if I am remoted into a machine. Is there a way to disable this? Alternatively, a way to disable this and then invoke as needed ...
5
votes
3answers
1k views

How can I have ArcGIS not automatically add raster clip output from Python window to the current map

I have a collection of rasters that I'm writing code to automate clipping based on a user defined shapefile. I am currently doing this in the Python window using the following as the main processing ...