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

learn more… | top users | synonyms

2
votes
3answers
3k views

Viewshed / Line of Sight analysis- as a batch process?

I wish to carry out a line of site analysis similar to the subject in here (preferably within QGIS): Visual Impact Assessment in QGIS or GRASS Scenario: I have two points, A and B. Point A is a ...
1
vote
1answer
216 views

no output file with grass:r.los

i'm using qgis 2.0 and i want to calculate a viewshed using r.los from grass tool box. after typing in the python console and a few seconds, i don't get an error message, but there is no file. the r....
4
votes
1answer
235 views

Any way to perform zonal statistics on column other than value or do reclass faster?

I have to perform ArcGIS zonal statistics on a raster, but the column I am interested in is not the 'value' column. Now, I can reclass the raster so that the column of interest becomes the 'value' ...
2
votes
2answers
359 views

Is there a way to do a python batch script for Analyze and Compress on SDE Databases?

I created and modified python scripts based off of ERSI's example (http://resources.arcgis.com/en/help/main/10.2/index.html#//003n000000v7000000), however, what would be great is to be able to batch ...
2
votes
2answers
638 views

unable to call shp2pgsql using python

I am unable to call shp2pgsql using python as I have to pass various options like (-s -a -i) and I am not getting the required output .. Method I am using is p1 = subprocess.Popen(["cmd", "/C", "...
4
votes
1answer
623 views

Plugin Tutorial issue: trying to work around changes in QGIS API

I'm currently following the tutorial to create my first python plugin for QGIS: http://www.qgisworkshop.org/html/workshop/plugins_tutorial.html and have similar issues to this thread: QGIS 2.0 Plugin: ...
1
vote
1answer
1k views

Slow tiles generation for leaflet js

I am currently trying to use leaflet to display images (jpeg or png) instead of maps, I have followed the instructions on this blog post to create the tiles using gdal2tiles.py here is the code we ...
1
vote
1answer
876 views

ArcGIS arcpy reprojecting raster issue

I have a raster which I want to reproject from GCS_WGS_1984 to GCS_NorthAmerican_1983. I am using the following code: try: spatial_ref = arcpy.CreateSpatialReference_management("GEOGCS['...
0
votes
1answer
285 views

problem with SelectLayerByAttribute management in script

hello my problem is that this tool works perfectly in IDLE or PyScripter programs, but if I use in the script in ArcGIS desktop this problem occurs: arcgisscripting.ExecuteError:ERROR 000582... why ...
1
vote
2answers
376 views

How to get an indication of how points are spatially distributed?

Let's say I have a set of points and I want to get an indication of their spatial distribution. That is, if all points are at one location a possible return value would be 0, whereas if all points are ...
1
vote
0answers
239 views

Install PyQGIS in virtualenv

Is it possible to install PyQGIS in virtual environment? I want to use rendering capabilities in my own application which runs using virtualenv.
2
votes
3answers
337 views

Best way to find points outside state boundary that are supposed to be within specific State

I have a nationwide featureclass called bakeries. In the bakeries FC, there is a field called "State" and the field is populated with state abbreviations(AL,NJ,CT,etc). I have another feature class ...
0
votes
0answers
187 views

ArcGIS Python Field Calculation

Ok so i've got a problem with the field calculator in ArcGIS: I'm already pretty far with it since i got some help :P but it still doesnt work. What i've got: -A complete table of several states of ...
1
vote
1answer
81 views

How can I pan an ArcGIS map from an external application?

I have a web application with geocoded addresses. I would like to be able to click on an address within that application, and have ArcMap 10 respond by panning the map to the corresponding location. ...
4
votes
1answer
2k views

call Sql Server stored procedure form arcpy

Is there a way to execute a SQL Server stored procedure with arcpy or Python and retrieve the results returned by the stored procedure? There is a very similar question posted on ArcGIS forum with ...
0
votes
0answers
204 views

Spatialite not available from qgis python console

I have a problem using pyspatialite from within the qgis python console. When I run the following code in ipython from pyspatialite import dbapi2 as sqlite conn=sqlite.connect("MyDB.sqlite") cur=conn....
0
votes
0answers
119 views

How to get the color of a vector layer in pyQGIS?

I have see this topic (How to change the color of a vector layer in pyQGIS?) but I'm looking for get the color not to change. How I can resolve my problem ? Thanks
3
votes
0answers
191 views

Handling non-spatial data for QGIS projects with Camelot

Most of my projects include data which is non-spatial or which is point data and can be managed by a regular relational database. Previously I found Manifold and ms-access were a good combination ...
2
votes
0answers
109 views

QGIS: rotatable markers with offset from point

Im wondering, if its possible (in QGIS), to set a rotatable marker with offset from point, like in my example below. Any suggestion?
1
vote
1answer
454 views

How to export Raster to JPEG in Python?

I built a model to import table data, create xy event, kernel density and clip density raster. I would like to export the clipped raster as a JPEG but I am not sure how to write the ExportToJPEG code. ...
6
votes
2answers
5k views

Creating Shapely MultiPolygons from shape file MultiPolygons

I'm reading a shapefile using Fiona: with fiona.open('data/boroughs/boroughs_n.shp') as source: mpolys = [p for p in source] candidate = polys[0]['geometry'] this gives me a dict containing a ...
1
vote
1answer
136 views

How does the tolerance influence QgsGraphBuilder and tieing of points?

I am developing a script which uses OpenStreetMap data to calculate the distance (over the road network) between each building and the nearest hospital. To do this, I mainly follow the official ...
1
vote
1answer
226 views

Why does connect to Excel spreadsheet through ArcPy give ERROR 000582?

My ultimate goal is to automate kernel density analysis on xy data from a table. I am trying to learn Python but I am very new. I built a simple model to take table data and display xy data. When I ...
1
vote
1answer
150 views

How to get a kml from stored in a blob file of oracle with arcpy

How to get a kml from stored in a blob file of oracle with arcpy? i try get data or kml files contains in a database oracle in a field of a table, using cursos options of arcpy. import arcpy, os ...
6
votes
2answers
3k views

How to get field names in pyqgis 2.0

I am trying to change an plugin from QGIS 1.8 to 2.0. In the 1.8 version I create a table of the field names like this: layer = vlayer provider = layer.dataProvider() feat = QGSFeatrue() allAttrs = ...
8
votes
3answers
10k views

How to write Shapely geometries to shapefiles?

Can someone demonstrate a simple way to write geometry data-structures from shapely into shapefiles? I am particularly interested in polygons with holes and linestrings. It would also be beneficial to ...
0
votes
0answers
876 views

Creating multiple feature classes from multiple text files using python

I have a folder with multiple text files. I am writing a code that reads all of the text files, and creates a point feature class (i.e. a shape file) for each one. The text files are all tab ...
7
votes
3answers
1k views

How to count the number of lines connected to a point?

I have a water network which and I need to install elbows and Tees (T). When 2 lines connect to a point, I want to install an elbow, when 3 lines connect, I want to install a Tee. How do I get ...
5
votes
1answer
390 views

How can I get the field index of the new layer in my script using Python?

I am trying to use layer.changeAttributeValue(fid, fieldIndex, value) to add values to a field in QGIS Basically, I'm creating a plugin which will, if a checkbox is ticked, create a new field, then ...
5
votes
2answers
4k views

Loading PostGIS raster layer into QGIS

I am unable to load a PostGIS raster layer into QGIS. I have looked through previous posts Loading raster from PostGIS DB into QGIS and Cannot add the PostGIS raster layer with QGIS but was not able ...
1
vote
1answer
64 views

How to automatically add identical new polygons to a layer?

I am seeking a way, using QGIS, to automatically add polygon features identical to others on the layer. In this case, they are water valves on a water network. Anyone know of a user-friendly way to ...
0
votes
1answer
925 views

Custom forms and Python logic: attribute error [closed]

As a beginner to Python, PyQt4, AND QGIS, I am attempting to work with the custom forms feature in QGIS. At this point I'm not sure if my error comes from the code or the .ui. This blog gave me a ...
1
vote
2answers
4k views

os.system /subprocess.call error handling when error in command line function?

In my Python script I call a GDAL utility using: subprocess.call('gdal_rasterize -a ICE_TYPE -where \"ICE_TYPE=\'Open Water\'\" -b 1 -burn 5 -l ' + shapefileshortname +' ' + shapefile + ' ' + ...
0
votes
1answer
1k views

How to disable the Escape key for a dialog? [closed]

I may have found the solution to my own question but I have another problem. It turns out that the user can just hit "Esc" and close the form. How can I disable the escape key? I'm looking for some ...
1
vote
1answer
213 views

Python scripts of GRASS in QGIS 2.0

I want to use v.kriger from GRASS through sextante QGIS 2.0, but this command is not here. But I find, in C:\OSGeo4W\apps\grass\grass-7.0.svn\scripts, the command as a python script. How can I use ...
6
votes
4answers
3k views

How to check via Arcpy if ArcMap is currently in an edit session or not?

I've created a Python add-in button that helps speed up my coworkers workflow by copying one feature class attribute to another. It uses the arcpy.UpdateCursor function to update a row in the target ...
1
vote
1answer
204 views

How can i change vertex option programmatically using python in QGis?

I want to activate the option "Show markers only for selected features" in Setting-> options->vertex markers ,using python. does anyone know if i can do it programmatically ? i attached a photo of the ...
2
votes
0answers
218 views

How to display images as cross sections in 3d

I want to display a base map and several vertical cross sections in 3D. The base map image is easy to rectify as a geotiff. How can I also display the cross sections? The cross sections are at ...
-2
votes
2answers
486 views

Python script not working after exporting it from ModelBuilder

trying to figure out why my script wont work (I should mention I'm still at an intro level). This is a script I exported from ArcGIS model builder which worked fine using that: # Import arcpy module ...
1
vote
2answers
180 views

Old Windows Installers for python library fiona

Due the the recent bug as presented here for fiona 1.1, i am obliged to use a version of fiona in 1.0.x on windows 8.1. however, i can't find older versions of the installer at here. Are there any ...
2
votes
0answers
76 views

Using the geocode function with cursors

How do I use a cursor with a geocodeaddress function? I want to be able to: 1) read from a table 2) only geocode addresses(from table1) whose street number is not 0 using a cursor 3) then update a ...
1
vote
1answer
4k views

Delete first two letters from a string field

I'm looking for a field calculator python statement to delete only the first two letters of string entries. For Ex: !Name!.strip([0:2]) I know this syntax is incorrect. Thanks a lot
0
votes
1answer
220 views

Installing Lecos plugin for QGis 2.0.1 on linux fedora 20

I try to install Lecos plugin, which requires python imaging library (pil), but the installation fails with the following: "you need to have the image library pil installed" I installed the python-...
-2
votes
1answer
652 views

QGIS converting to ASCII question

I am attempting to do some analysis on a raster file and I need to convert it to ASCII. In QGIS, I used [Raster -> Conversion -> Translate] with the asc file format, and I suspect it is simply ...
0
votes
0answers
201 views

ArcMap 10.2 SplitLineAtPoint setSplitRule not calculating RATIO

I am trying to set a length field to use the RATION split policy. I set the split policy for the feature layer but when I use the SplitLineAtPoint_management it does not calculate the RATIO length. ...
1
vote
0answers
123 views

header information is missing from image, after writing using opencv

I am doing complement of an image using open-cv python, while writing the image, open-cv is not writing the header information in the complemented image. my image data are in TIFF format. i am doing ...
1
vote
1answer
158 views

Is it a good idea to use GRASS Algorithms for Geoprocessing in a Server Environment?

I´m designing a web-service to run in a server environment that will do some geoprocessing actions to datasets uploaded by users and send the results back. I´m programming in Python, and so far I´ve ...
1
vote
2answers
598 views

Using python to get extent and split coordinates into list

I have the following code: for fc in fcs: desc = arcpy.Describe(fc) ext = desc.extent ext.split(" ") print ext I'm getting error: AttributeError: Point: Get attribute split does not ...
3
votes
2answers
597 views

Python, GDAL, VRT: help wth code efficiency and processing time

I'm going to attempt to make this question as succinct as possible while still including relevant information, as I have trouble with being concise and am trying to avoid writing unnecessary stuff. ...
0
votes
1answer
122 views

python tool parameter: what datatype to list unique values of field?

I'm attempting to convert a 9.3 arcobjects tool to a 10.2 python tool. The form needs to allow user input of a shapefile, a field, and then the user needs to enter numbers corresponding to unique ...