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

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2
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3answers
116 views

Find coordinates of given raster value

I would like to get the coordinates of a raster cell with a given value. I suppose many cells can take the same value, in which case several coordinates should be returned. In my first problem I'm ...
2
votes
2answers
136 views

How can I select features based on another feature attributes?

Here is my case: I have a layer of features (buildings from a city) that is populated with polygons. This polygons have attributes : street name and postal code In the project I have another layer of ...
2
votes
1answer
83 views

QGIS select reversed geometries

I have a road network and a geometry for each road direction. One Geometry from A->B and another Geometry from B->A. This geometries are covering each other. Is there a tool available in QGIS to ...
2
votes
1answer
52 views

Arcpy PointGeometry does not carry forward the ID

I used this as starting point I have the following code: Test data data = numpy.array([(0, 51.1047664, -114.3722785, 1205, ...
2
votes
1answer
60 views

How to find length of a discontinued line feature

I wanted to find the length of features in a road layer. So I go through each feature in the layer and used, line = feature.geometry().asPolyline() to find the points which particular feature is ...
2
votes
4answers
244 views

Converting a large set of GRIB2 files to a spreadsheet format

I have a large set of .pgrbf.grb2 files downloaded from the Climate Prediction Center, and I need to run statistical analyses comparing them to data that was produced locally in .csv format. I'm not ...
2
votes
2answers
207 views

Store result from gdallocationinfo as variable in python?

I'm trying to find the cell value at various locations in a set of rasters so I can count the number of real values (aka not 'NoData') that occur at all the locations within each raster. The various ...
2
votes
1answer
170 views

Changes not persisting in ArcGIS server from ArcPy script

I have a ArcPy script (10.2) which connects to an ArcGIS server (10.0) versioned geodatabase, via an .sde connection file in the Database connections directory through direct connect on a Microsoft ...
2
votes
1answer
496 views

Georeferencing a raster using GDAL and Python

I want to georeference a raster using python and GDAL. My current approach is to call gdal_translate and gdalwarp using os.system and an ugly list of ground control points. I'd really like a way to do ...
2
votes
2answers
85 views

ArcGIS Field Calculator passes European-formatted floats as tuples

I have the problem that the ArcGIS Field Calculator doesn't read a float number when it is included in Python by referring to the field that contains it, in this way: def giveResult(floatValue): if ...
2
votes
1answer
207 views

select random rows with python in arcgis

I am new to using Python in ArcGIS, and I wonder: how do I select random lines (or every two lines) of an attribute table? I must select these lines and calculate them, so they are different from ...
2
votes
1answer
182 views

arcpy with multiprocessing throws “UnpickleableError: Cannot pickle <type 'geoprocessing Layer object'> objects”

I'm attempting to speed up a process which is currently running synchronously, by using the python multiprocessing module. I'm having trouble sending a feature layer to a function which is called by ...
2
votes
1answer
389 views

How to properly import QImage from PyQt4.QtGui?

I am starting with QGIS python console. Naturally, I came across the PyQGIS Developer Cookbook. While trying to cut my way through it, I encountered a lot of problems with "undefined attributes and ...
2
votes
1answer
229 views

Python loop with address locator

I was given a list of addresses without any zip codes, and I'm trying to write a python snippet that will loop through a set of possible zip codes and make a set of geocoded shapefiles that I will ...
2
votes
1answer
209 views

Cannot load postgis layer from sql string in pyqgis

I'm trying to load a layer using the following code in qgis python console: sql = "(select the_geom, ID from mytable)" uri = QgsDataSourceURI() ...
2
votes
2answers
466 views

How we can get output for os.system() in python?

I wrote the following command in Geoserver rest-api using curl: cmd=curl -v -u admin:geoserver -XGET -H "Accept: text/xml" ...
2
votes
1answer
80 views

How do I rename rasters in an mxd by using my csv?

I have the following data in a csv: RasterName First name Raster 1 Aaron Raster 1 Paul Raster 2 Bryan Raster 3 Cranston Raster 3 Vince I have added these ...
2
votes
1answer
451 views

UnicodeDecodeError: While installing gdal in a new Python Virtual Environment

I was trying to create a Python Virtual Environment for some initial GIS development. I installed pip and virtualenv and then tried the following commands from the Linux-Terminal to accomplish the ...
2
votes
1answer
339 views

Pyproj: converting WGS84 to Robinson

I have a WGS84 coordinate pair (37.7749295, -122.4194155). I have an image that is a Robinson Map Projection of the world. I'm trying to write a python script to locate my WGS84 coordinate on my ...
2
votes
1answer
106 views

Problem with Python codeblock recognizing a field

'<'First Post Alert> I've been through multiple iterations / gyrations, and while there may be multiple problems here (and I'll appreciate feedback on all of them), the recurring issue is that the ...
2
votes
1answer
661 views

Is there any way to fast read pixel value using gdal in C#

I create with C# a series of lat/lon value pair in the code(using i, j loop) and I want to extract the pixel value based on either lat/lon pair or pixel location (i, j). I know there is one gdal ...
2
votes
1answer
70 views

raster overlap count

Would it be possible to simply detect and count overlaps between raster files, i.e. not polygons against rasters, using arcpy? By default I don't have the spatial analyst extension for ArcMap 10.1 but ...
2
votes
1answer
769 views

Python support with QGIS 2.4 on Ubuntu 14.04

I recently updated my Ubuntu system to version 14.04. I added the sources and installed QGIS as per the directions on the QGIS website. Everything looks good, except for I do not have all the ...
2
votes
1answer
127 views

How to find missing dependencies in a distributed ArcGIS Python toolbox?

I am developing a Python Toolbox that uses a few external libraries (ogr/gdal, matplotlib, shapely, reportlab among others) which files I have directly copied in the same folder as my toolbox .py, as ...
2
votes
1answer
195 views

How to use the MMQGIS plugin through the Python console?

I know how to make Hub Lines using the GUI, I want to know how to do the same using the Python Console, a tutorial would be great. Thank you
2
votes
2answers
214 views

How to switch to edit mode vector layers, in pyqt application based on qgis?

I do QGIS based application, I need to implement the ability to modify the geometry of vector layers in manual mode (editing nodes), how to do it?
2
votes
1answer
58 views

Zoom option error on gdal_tiler.py

I'm using the tiler-tools library from: https://code.google.com/p/tilers-tools/wiki/QuickStart And specifically this command: ./gdal_tiler.py --zoom=9-15 my_map.vrt To generate tiles. When I use ...
2
votes
2answers
696 views

GDAL_CALC works but I get a python error at the end of each process that prevents automation

Python 3.4.1, GDAL 1.11.0, OSGEO4W, Windows 7, OSGEO4W Windows Shell All 64-bit (ArcGIS is installed as well 10.2 with Python 2.7) So gdal_translate works fine. gdal_calc provides perfect ...
2
votes
2answers
209 views

How to calculate monthly maximum values from daily data in a 365 band grd?

I have a MINT2005.grd file which has 365 bands representing days of year from 2005. Each band is a 32x35 matrix representing the temperature at different latitude and longitude pair. How do I ...
2
votes
3answers
579 views

convert a shapefile into graph with nodes and edges

Is there a way to convert a shapefile into graph with nodes and edges(except networkx). I'm using qgis and I want to convert a road vector layer into a graph, so that I can use it to apply shortest ...
2
votes
1answer
300 views

QGIS Python Scripting - Syntax definition

After playing around with the Model Builder and looking at the python scripts of what I make, I noticed some syntax which I can't find the definition anywhere. Here is a snippet of the python script ...
2
votes
2answers
98 views

Issues Reading a table from Geodatabase

I have scripted a process to read a CSV file into a file geodatabase. Then, I want to read this imported file and work on it by adding new fields and calculating values. However, while using the ...
2
votes
2answers
702 views

How to create a Shapely LineString from two Points

If have two points, from which I want to create a straight LineString object: from shapely.geometry import Point, LineString A = Point(0,0) B = Point(1,1) The Shapely manual for LineString states: ...
2
votes
1answer
78 views

Finding Code in QGIS Select Features Toolset

Can anyone tell me in what directory the pre-installed Python scripts for the QGIS selection tools (i.e., Select by Point, Select by Polygon) are found? I am using on a Windows 7 installation of QGIS ...
2
votes
1answer
485 views

Determine Equal-Area Slope of Longest Water Course in Catchment

I'm still very new to python and need some direction in developing a Arcpy\Python script to determine the Equal-Area Slope of the Longest Water Course within a catchment. The Longest Water Course is a ...
2
votes
1answer
248 views

How can I extract only band 4 from a geotiff multi bands to create geotiff or AAIgrid with this band using Python?

I have a geotiff file with many bands... I will like to create a .asc file or tiff file by converting only one band from the geotiff file. I don't find the solution by using python... With ...
2
votes
2answers
118 views

ArcGIS - Extract by Attibutes in Model Builder

I have a model which at one point uses the Extract by Attributes tool to produce a new raster with just the areas containing the maximum values of the first. I would think that the SQL expression ...
2
votes
2answers
215 views

Update raster value to reflect total number of points within cell- python

I have what should be a fairly simple task, but I can't seem to figure out how to do it. I have to do it in python/arcpy/gdal/whatever because I'm trying to automate this process for a hundred or so ...
2
votes
1answer
166 views

How to Format Description when writing Help for Python script tool?

I try to format the description in script tool but I don't know how it works so i don't manage to add a line break for example. Does it works with HTML tags ? When editing my script the description ...
2
votes
2answers
225 views

Why is arcpy.StackProfile_3d -> arcpy.SaveGraph_management creating empty graph?

In a python script I'm trying to save a graph to a .png file with graph output from arcpy.StackProfile_3d but the .png file shows an empty graph. The table created from arcpy.StackProfile_3d shows ...
2
votes
1answer
371 views

Using 'construct points' on all lines in a shapefile (arcpy)

I need to use the editing tool 'Construct Points' on several shapefiles that each have ~1300 polylines. I need to do this to create points every 1km along each of the polylines, which represent the ...
2
votes
2answers
260 views

How to save python ogr2ogr shapefile to memory, and stream to web client as zip

I'm trying to accomplish something similar to the site http://ogre.adc4gis.com/ I want to be able to manipulate a geojson file, and send it to the client as a shapefile, in a single zip file. I'm ...
2
votes
1answer
1k views

import qgis.core problem with QgsFeature and QgsGeometry

I've tried several previous answers to similar questions - no luck. I run Win7. I installed QGIS 2.2.0 using the OSGeo4W 32-bit installer. Problem 1) from qgis.core import * failed. Solution 1) ...
2
votes
2answers
268 views

How do I load mapinfo mid/mif into geopandas?

I suspect this is a trivial question to answer but how do I load mapinfo mid/mif files into geopandas? While it's trivial to load and manipulate .shp files, I can't work out what code to use: Here's ...
2
votes
2answers
859 views

What is the most efficient way to iterate through folders and geodatabases?

I am looking at cataloging some data, and I have code that works, it just seems to take a lot of time to run through all of the items. The way this data is structured is a bit of a hindrance, ...
2
votes
1answer
123 views

If Then Modelbuilder, Project error

I have a model where I want to check the projection. If it is GCS_WGS_1984, I want it to go one path, and if it isn't, I want it to go another path. I created a "Check Coordinates of Input" script ...
2
votes
1answer
316 views

Transferring data between spatial databases

I would like transfer spatial data from PostGIS to Oracle Spatial. I want to use Python's modules psycopg2 and cx_oracle. Transfer Oracle > PostGIS is OK, but in opposite version I have problem with a ...
2
votes
1answer
923 views

Read and Export OSM Road Data as a Network of Road Segments [Adjacency Matrices]

I wish to extract from an OSM file a road network, and export it as an array (adjacency matrix) where the nodes are the road intersections and the edges represent the road segments. I don't want to ...
2
votes
2answers
238 views

Can I use the LEFT (string) operator in ExecuteSQL()?

In QGIS I can use the LEFT operator on a dataset like this: LEFT( "Name2",3) ='031' What is the syntax for using this expression with ogr in python? Isn't this the right syntax? ...
2
votes
2answers
579 views

How to create equidistant points in QGIS along a polygon?

I am looking for a solution to distribute with a python script equidistant points in QGIS along a polygon. I tried to use the following code example: ...