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

learn more… | top users | synonyms

1
vote
0answers
44 views

Arcpy PageLayout.dll Errors in Python

import os import arcpy arcpy.env.overwriteOutput=True folderPath= raw_input ("Enter directory: ") filePath= raw_input ("Enter data repository: ") f = open((os.path.join ...
1
vote
0answers
18 views

Q: cursor memory and fields therein

Theoretical Python question. Say you have an update cursor while-loop for a few selected records. While looping through the rows, at some point a nested if statement triggers an "addfield" event. The ...
1
vote
0answers
131 views

Editing of vector layer programmatically with QGIS

I'm trying to edit vector layer using Python console and have couple of questions. Why this approach doesn't work and I have to use canvas.refresh? If I will use this code not in python console but in ...
1
vote
0answers
98 views

Accessing existing instance of qgis from stand-alone python script

For my own data analysis pipeline, I am running a split screen setup with iPython notebooks on one side, generating variables from source data, pushing them to a csv file which qgis then reads/joins ...
1
vote
0answers
80 views

Is it possible to get field type information from FieldInfo object in ArcPy?

I'm looking at the FieldInfo object documentation for ArcGIS 10.2 and am not seeing access for field type (e.g. short, string, double). Is it possible to get field type information from the ...
1
vote
0answers
182 views

Locating the centroid (center of mass) of spherical polygons

I'm trying to work out how best to locate the centroid of an arbitrary shape draped over a unit sphere, with the input being ordered (clockwise or anti-cw) vertices for the shape boundary. The density ...
1
vote
0answers
60 views

Russian in fieldname changing with Python in ArcGIS

Is there any way to rename fieldname in the attribute table of a layer/shapefile in ArcGIS 10.2 containing russian letters? If yes, is it possible to do it in a script?
1
vote
0answers
60 views

How to create a startup prompt that populates definition queries on multiple feature classes

I would like to create an ArcGIS start up prompt or custom button that asks for a user's initials and then populates multiple feature class & layer definition queries. More specifically, I would ...
1
vote
0answers
64 views

Access to python addin objects/variables in python window

Following up on this question: Can a Python script be executed from a .NET AddIn and also write its standard output and geoprocessor messages to the ArcMap Python Window? Is is possible to access ...
1
vote
0answers
166 views

arcpy symbology colors changing on RefreshActiveView()

I have a problem that I'm not sure is functionality not built into arcpy or I'm just doing something wrong. I'm using arcpy.mapping.UpdateLayer() to apply symbology to a layer, but afterwards some ...
1
vote
0answers
62 views

What is the best way to handle geometries between Python functions?

What is the best way to handle geometries between different Python functions? For example: I have a function that exports a line from grass.script. The line will be a parameter of another function ...
1
vote
0answers
103 views

GDAL and Python: How to “pad the extent” or otherwise handle band.ReadRaster() for area falling slightly outside the image bounds?

In a nutshell, I'm trying to create a bare-metal tiling utility using GDAL and Python. As you can see in the graphic below, which shows the perimeter of a raster and the OSM-structured tile index, ...
1
vote
0answers
187 views

Unable to use pyQGiS in a custom application - import arcgis.core error

I'm using windows 7 and/or 8 64 bit with QGiS 2.01. I'm wanting to us the pyQGiS tools in a custom python application outside of the QGiS environment (i.e by running a python executable located in ...
1
vote
0answers
111 views

Matplotlib Basemap Resolution with PyQt makes Python Quit Unexpectedly

I'm having difficulties using Matplotlibs Basemap in combination with a PyQt4 interface. Basically I create a Pyqt4 Canvas in which I plot a Matplotlib Basemap and some markers. I call the function in ...
1
vote
0answers
92 views

Efficient computation of path profile with Numpy and GDAL

I have numpy array with SRTM elevation data and I need calculate path profiles - vectors with elevation data from one point (transmitter) to every points of my map. Here's my current solution: def ...
1
vote
0answers
84 views

AttributeError: Error in getting tool information when using TableToTable tool

I am trying to use the arcpy.TableToTable_conversion tool in my python script, but seem to be getting the following error on the line arcpy.TableToTable_conversion("FINAL_NLPG", ...
1
vote
0answers
120 views

Composite bands produces a single band image

Running this produces a single band tif and not a three band image. Has anyone seen this before or can suggest ways to trouble shoot it? Input_Rasters = path + parentdir + "/" + dir + "/" + ...
1
vote
0answers
232 views

Couldn't load PyQGIS, QGIS 2.0.1 on Ubuntu 12.04 Precise

After upgrading to QGIS 2.0.1 I still get the error: Couldn't load PyQGIS. Python support will be disabled. Traceback (most recent call last): File "", line 1, in File ...
1
vote
0answers
54 views

Obtain virtual output directory path in geoprocessing service

I am publishing a geoprocessing service and I want to be able to access the virtual output directory path configured for the service. Now I know that gp services will magically return virtual paths ...
1
vote
0answers
146 views

How to change the color of a selected feature with pyQGIS?

is it possible to change the color of a selected feature in qgis 1.8? To highlight a feature I use: vlayer.setSelectedFeatures(selectedList) box = vlayer.boundingBoxOfSelected() ...
1
vote
0answers
81 views

How to join attributes by location with command line

I would like to joint the attributes of 2 shapefiles by location but with a command line (linux). This feature is easy in QGIS but it is VERY slow. Is there a way of doing this with ogr or pyqgis ? ...
1
vote
0answers
168 views

merge_management

Here is the edited code: import arcpy import os from arcpy import env set the environment settings env.workspace = "C:\RG\Kings County\Test.gdb" fcs = arcpy.ListFeatureClasses("Sub_NVF_*") ...
1
vote
0answers
206 views

Pyshp 1.2 example from documentation fails

I must be doing something really stupid because I am trying to run an example straight from the PyShp (shapefile.py) 1.2 documentation with the only change being the input shapefile and it is failing. ...
1
vote
0answers
132 views

Modifying Raster Layer with Python Console

Forgive me if this has been asked somewhere else. I am looking for a way to edit a raster file which has already been loaded into QGIS through the python console (i.e. I would like to edit the raster ...
1
vote
0answers
82 views

Reference to Basemap instance's coordinate system

I use the matplotlib basemap toolkit (mpl_basemap.Basemap) to plot GeoTIFF images on a map background using pcolor() or pcolormesh(). For this purpose, I need to transform a meshgrid of x and y ...
1
vote
0answers
71 views

How to create a schematic view of a line feature?

DEAR PEOPLE FROM THE FUTURE: Here's what we've figured out so far… I have a line feature (polyline with curves) in ArcGIS Desktop, and I want to create a linear representation (straigth line) of the ...
1
vote
0answers
39 views

Qgis 1.9 commitChanges() and Redraw a temporary layer

Using QGIS 1.9 and writing a python plugin. I have a function that connects points into polylines and draws them as a temporary, in memory layer. Membership in a polyline is determined by a field in ...
1
vote
0answers
179 views

Calculating the closest distance between two points in ArcMap 10.2

I am looking for a script to calculate the closest meter to a set of addresses. I have a feature class of meters and a feature class of addresses. I have populated the address with fields for ...
1
vote
0answers
74 views

Automated attribute update geometric network

I have a Network Dataset of a storm water system containing two feature classes of points and lines. (All data is topologically sound with pits and pipes snapped and linework captured in direction of ...
1
vote
0answers
63 views

How to rotate u and v components of wind in rotated gribs?

I have a grib message of a rotated hirlam product. The gribmessage states, that the u and v component contained are relative to the rotated grid. How can I unrotate them?
1
vote
0answers
43 views

Deleting network features in python script doesn't create net junctions

I have a script that makes a copy of a network dataset for a 3rd party app to use. One of the junction feature classes causes problems with the app. The ideal solution would be to remove it from the ...
1
vote
0answers
128 views

Can ModelBuilder be used to export different versions of the same mxd with various constraints?

I am currently trying to use modelbuilder to go through each row in an attribute table, select the streets that intersect the polygon (which is the row in the attribute table), zoom to the selected ...
1
vote
0answers
225 views

Loop though records in PostGIS (using PL/PYTHON or PGSQL)

I've seen many example of loops, but I can't get that one to work. I work for a regional transit agency and each year, we conduct several surveys. I geocode everything to the house level for internal ...
1
vote
0answers
88 views

how to avoid Intersection of polygons via python code

i am using QGIS 1.8 and i can set the check box in Setting\Snapping Options "Snapping and Digitizing " dialog to avoid polygon intersections and enable topological editing but i am looking for a way ...
1
vote
0answers
255 views

Why does ArcGIS Resample tool change cell size and numbers of columns and rows?

I am working with images of oxygen distribution within individual plant root systems submerged in water. The program I use to acquire these images, LookatRGB, splits the green band in half and makes ...
1
vote
0answers
153 views

problem with WFS Data, GDAL, Python, ArcGIS, & Defining Projection

I'm pulling in data in gml2 format with a EPSG#4267 from a wfs. I create a datastream in python and then run the following from the python window in ArcMap: data = datastream.read() #write the gml ...
1
vote
0answers
126 views

How to shift vertices of shapes in shapefile using FOSS python library?

I need to shift each vertice of shape in a shapefile (of any type:point, line, polygon, multiline etc.) with Python. I need to loop in all shapes, get the vertices, get it's coordinates and for each ...
1
vote
0answers
200 views

XY event source layer problem (converts into feature class after running python script ) in ArcMap 10.1

I am using ESRI 10.1 suit (ArcGIS Desktop & ArcGIS Server, No ArcSDE) at my end and after running python script n number of times event layer converts into feature class. Following steps I am ...
1
vote
0answers
132 views

How to create multi-image single band single file geotiff?

I have a geotiff file that is single band but contains multiple subdatasets. I use gdal with numpy to open a specific subdataset and mask some of its values. Example: $ gdalinfo sample.tif ... ...
1
vote
0answers
173 views

Add metadata to dataset (feature class, coverage or shapefile) from a .csv using arcpy?

I am looking for a script that will take metadata information provided in an excel table, convert it to a .csv and import the values to populate some of the dataset's ArcGIS metadata elements. I came ...
1
vote
0answers
79 views

QGIS GPS bluetooth connection

I have setup a Haicom bluetooth gps on a machine running Windows8 and have used GPSGate to create some virtual COM ports. I have valid data arriving at the COM port, but then I run QGIS and try to ...
1
vote
0answers
34 views

Problem in analyzing data in a stream segment

I have to find out the head difference along the stream segment. For that I used Spatial Analyst Tool>Extraction>Sample. With that I got the elevation values in points. But after doing so, i found ...
1
vote
0answers
56 views

Ubuntu Raring - Openlayers Plugin 1.8 or 1.9 Master

Relative newbie to Ubuntu and QGIS. Many questions are posted relating to the Openlayers plugin. It works fine in windows but I cannot get it to work or even appear in either 1.8 or 1.9. The "fetch ...
1
vote
0answers
108 views

Python Script Producing Empty Cost Path Rasters

I'm trying to run a script that will create cost paths for a large number of randomly generated points then assign the cost to those points. But my script is beginning to create cost path rasters ...
1
vote
0answers
250 views

Install shapely for QGIS on Mac

I know there are a number of similar questions, but none of them have answers that allow me to use shapely in QGIS. In particular I am trying to install the Contour plugin, but this fails with the ...
1
vote
0answers
87 views

Subset a GeoTIFF image into regular grids and extract mean latitude, mean longitude, and mean RGB for each grid

How can I subset a GeoTIFF image with 1000 by 1000 pixels into regular square grids of 50 by 50 pixels (400 grid objects in total); and calculate mean latitude, mean longitude, and mean RGB for each ...
1
vote
0answers
243 views

Why does XYToLine_management give ExecuteError ERROR 999999 The table was not found?

I've written this script to import a csv file using ArcGIS' flavor of python.. ArcPy.. It seems to run fine up until the XYtoLine tool runs and then it fails.. This is the error message... Traceback ...
1
vote
0answers
252 views

Python Addin toolbar- Environment mask parameter not being recognised?

I've created a button on a python addin toolbar which uses the selected features from the selected layer in the TOC, creates a feature layer from that selection and uses that feature layer to set the ...
1
vote
0answers
235 views

How to write vector layer to csv file with geometry by PYTHON?

I use Python try to write vector layer file to csv file with this code QgsVectorFileWriter.writeAsVectorFormat(mylayer, r'c:\temp\xyz.csv', "utf-8", None, "CSV") It can export to xyz.csv but only ...
1
vote
0answers
87 views

Python GDAL/OGR: check lines geometries connectivity

I'm working with shapefiles representing roads, so basically it's stored as (poly)lines. I need to perform a road connectivity checking. In other words, I want to ensure that roads meant to ...