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

learn more… | top users | synonyms

2
votes
2answers
52 views

Install QGIS on ubuntu using the compressed format qgis-2.8.3.tar.bz2

I just cant use apt install becuase slower internet connection and size of QGIS can you show me how to do insall using qgis-2.8.3.tar.bz2 file. I have tried decompressing and use the command ...
2
votes
0answers
36 views

Creating new empty vector layer that has same set of atributes as another layer and then copying subset of features into it

I am new to both Python and QGIS. Here's a sample of my code: unique = layer.uniqueValues(index) attributes = layer..dataProvider().fields().toList() assistant_layer = QgsVectorLayer("Point", ...
2
votes
0answers
38 views

Multiple layer intersection

I am trying to find a way with qgis/python to get the intersection area of more than 2 layers. All the tools in Qgis take just the 2 input layers. ='( For example in the image below, I have 4 ...
2
votes
0answers
37 views

Cul-de-sac (curve) turns generation in flow for parallel lines using ArcGIS for Desktop?

I'm using ArcMap 10.2 and I need to generate a parallel lines within the polygon and connect them one to other with the curve, with the proper radius and return radius (the same as cul-de-sac tool ...
2
votes
0answers
53 views

GDAL with GEOS support, pandas and VTK using python on Windows?

So far I have been using OSGeo4W shell (or OSGEO install) as really convenient way to use python together with additional packages, namely gdal, shapely, numpy, scipy and matplotlib. I was happy till ...
2
votes
0answers
54 views

Gdal Python Problem : Black strips in geotiff

I am trying to use GDAL (2.0.0) Python API in Blender, but I am having some difficulties. I am trying to save geotiffs for : - a 2D numpy array storing 32bits floats - a 3 channels rgb numpy array ...
2
votes
0answers
36 views

QGIS QgsLayerTreeGroup signal “currentLayerChanged”?

In a pyqgis context, I use the "currentLayerChanged(QgsMapLayer *)" signal of the QgisInterface class to do something when the current layer is changed, but I need now to do the same when I select a ...
2
votes
0answers
67 views

Using Python to iterate through directory to create event layer and perform kernel Density for each file?

I am new to Python for ArcGIS, but have been using ArcGIS a while. I have a large directory of tables with point data. For each file of each folder I want to create a kernel density layer. I have ...
2
votes
1answer
75 views

Polygon found with search cursor, but not update cursor

Here's my issue. I am doing two things with arcpy: 1) I search a feature class using arcpy.da.SearchCursor() and pull out a UID field and the geometry in WKB format for all polygons in the file, ...
2
votes
0answers
38 views

Create a sript for “point sampling tool” of QGIS

Is there any way to create a python script to the "point sampling tool" plugin from QGIS? I have a very large number of Netcdf files which I want extrat the values from pixels to a irregular points ...
2
votes
0answers
53 views

QGIS not interacting with iface from python class

So I'm working on something where i need to use threads from python console of QGIS. The following line of code adds layer successfully iface.addVectorLayer("D:\ArcGIS Misc\Atlas\points.shp", ...
2
votes
0answers
79 views

How to create line segments between pairs of pixels in a raster?

I want to draw several lines between pixels (please see the image below) according to some criteria : First Criterion: The distance between 2 pixels is less than 2000m and greater than 500m ...
2
votes
0answers
51 views

How to clip or erase a csv file with a non-rectangular shapefile?

I can clip a csv file with a ogr2ogr having 4 extents of a rectangular polygon. Is it possible to clip a csv file with a non rectangular shapefile?
2
votes
0answers
58 views

GDAL equivalent to ArcGIS Union?

I have a single shapefile full of overlapping polygons. The ArcGIS Union tool will generate individual, non-overlapping polygons with that geometry. Is there a way to do this with GDAL/OGR or another ...
2
votes
0answers
192 views

open-source code for the map matching algorithm

For map matching of the GPS data to the network data, there is a algorithm from Schussler, N. & Axhausen, K. (2009a). Is this algorithm released under open-source license ? Where can I find this ...
2
votes
1answer
212 views

Extract data from netcdf using a shapefile polygon in python

I need to subset data from a NetCDF using a specific shapefile. The data are sea surface temperature and ocean color at 1/4 degree resolution. I have 4 polygons describing the US. Northeast ...
2
votes
1answer
90 views

Gdal_calc works but I get a pyhon error at the end of each process

I have a problem while using gdal_calc by a .bat file. Here is the code : call "C:\OSGeo4w64\bin\o4w_env.bat" gdal_calc ...
2
votes
0answers
55 views

How to run Focal Stats on specific values in python

I'm a beginning programmer and am new to the site but it has helped me quite a bit so thank you! I'm trying to recreate a raster calculator operation using python scripts but am having a hard time ...
2
votes
1answer
212 views

Processing plugin Python error on startup of QGIS 2.8.1

I've been running QGIS with no issues for several versions now, but after I upgraded to 2.8.1 Wien I had trouble running two plugins: qgis2leaf (which I believe depends on Processing) and Processing. ...
2
votes
0answers
101 views

How to access Landsat bucket from Amazon?

I tried to access amazon Landsat S3 bucket with the following python code import boto import boto.s3.connection from boto.s3.connection import S3Connection access_key = <userid> secret_key = ...
2
votes
0answers
48 views

Error inserting new column in ArcSDE table (ERROR 999999)

I am using a python script to populate a table with values I get from rasters files. I use arcpy.AddField_management to add a new column and arcpy.CalculateField_management to insert the values for ...
2
votes
1answer
50 views

arcpy.da.Walk not adhering to datatype filter “Locator”

I have a file gdb containing feature classes and address locators. I am listing and storing the names of the datasets using arcpy.env.workspace = "C:\input.gdb" (root, fds, ftrs) = ...
2
votes
0answers
42 views

Query out a specific date regardless of the time, using python

Problem: I have a feature class with an attribute table with a field called Edited_Date and its data in the field is as follows: 4/8/2015 10:00:00 PM. I want to select all records that are Edited_Date ...
2
votes
0answers
37 views

GDAL merge; Why add 0.1?

In the implementation of gdal_merge: https://svn.osgeo.org/gdal/trunk/gdal/swig/python/scripts/gdal_merge.py a value of 0.1 is added to the conversion from geo-referenced coordinates to pixel ...
2
votes
0answers
50 views

Not able to get the PostGIS Layer Viewer running in pgAdmin or command line

I've installed PostGIS Layer Viewer as a plugin for pgAdmin. I've downloaded postgis_viewer.py from the official repository on GitHub! and followed the install instructions described on Web site!. ...
2
votes
1answer
99 views

Implement r.cross / ArcGIS Combine with GDAL

I am using GDAL to process a lot of rasters. I then need to combine all the arrays to create a single output raster that represents all the unique combinations of values. I.E the same thing as ...
2
votes
0answers
86 views

How to use the multiprocessing module on python to execute a spatial join?

I have several shapefiles of the entire Amazon rainforest each with millions of polygons (they are fairly detailed and take some time to draw on ArcMap). I need each of these shapefiles to be ...
2
votes
0answers
42 views

Using ST_AsText() without session object

I am storing gps locations as feature in a restfull api. The locations are linked by foreign key to "place" objects in a flask/sqlalchemy/geoalchemy framework. I would like to print a user readable ...
2
votes
1answer
75 views

Memory issues with zonal statistics

I have got a memory issue due to the use of the zonal statistics command into a loop. It seems that after using the ZS command QGIS stores some information in the RAM (cache memory?). It is not ...
2
votes
1answer
128 views

Is it possible to find the feature class name from a python label expression in ArcGIS?

Does anyone know how to find the path to a feature class within a label expression using ArcGIS? I don’t need to simply display the path. My overall goal is to create a python function to display ...
2
votes
0answers
32 views

QGIS Python Script for RoadGraph plugin

I am looking to create a Python script that will take X,Y coordinates from one field in an attribute table, compare them to another set of X,Y coordinates in a different field, and populate a field ...
2
votes
1answer
107 views

QGIS gets stuck when running script to automatically refresh layer [closed]

I have a QGIS layer that represents a set of links and nodes to show the streets of a city and the traffic speeds on each street. I've been trying to write a script so that if I change the speeds in ...
2
votes
0answers
90 views

How to Bulk “Add Selected” Attributes to a Relationship Class ~ 40000 Records

I have 2 Feature Classes (FC's) and 1 Relationship class. FC1 and FC2 share a common field with almost 40,000 matching records. For each matching record (i.e. when the matching records from FC1 ...
2
votes
0answers
126 views

Updating attribute table from an Excel file using Python

I am kinda new to Python, please excuse for such a trivial questions. There is a shapefile (let's call it Materials.shp). I have an attribute table with different fields (for example, windows, doors, ...
2
votes
0answers
101 views

How to change the group icon in legend via Python in QGIS 2.6?

How to change the group icon in legend via Python in QGIS 2.6? At version 1.x I did it this way: self.legendTree = self.iface.mainWindow().findChild(QDockWidget,"Legend").findChild(QTreeWidget) ...
2
votes
1answer
114 views

Why does thumbnail on one MXD not update?"

I want to make modification on multi-mxd properties, I try Arcpy script with a loop like " for mxd in mxdList:" , but I always have same results, Thumbnails are not created... import arcpy,os ...
2
votes
0answers
45 views

Updating Cursor to Include Newly Created Features

I am using ArcMap 10.1 and python to create cursor that starts at the one and only row of a polyline shapefile, some code runs to create a new feature based on the position of the exisiting feature, ...
2
votes
1answer
192 views

How to plot trajectory points on maps in python

When I read the paper Characterizing Urban Landscapes using Geolocated Tweets, I'm attracted by the figures illustrated in it, like this: And I want to know how to plot these figures for my own ...
2
votes
1answer
91 views

conditional python script to delete records

I am new to python programming. I am wondering if someone could tell me how to write a python script that would find all records in an attribute table that have identical values in one field, then ...
2
votes
2answers
227 views

Debugging ArcPy ImportToolBox AttributeError: Object: Tool or environment <ConcatenateRowValues_AA> not found?

I am trying to use the ConcatenateRowValues tool provided by ESRI. My overall code for my script is working fine except when it tries to use the ConcantenateRowValues Tool. I start by importing the ...
2
votes
1answer
295 views

QGIS Python script for creating project file

Is there a way to create QGIS project file(.qgs) using only Python script outside QGIS Python console.I am trying to publish a map using QGIS Web Client using python. For this, I am trying to do below ...
2
votes
0answers
64 views

Via PyQgis how to refresh a modified CSV layer without having to reopen the file? [duplicate]

UPDATED: With an CSV layer Qgis workspace [loaded as a delimited text layer], an external algorithm is ran; outputting (writing) new values to certain rows in the layers source CSV file. The writing ...
2
votes
0answers
104 views

Error when running Python script to replaceDataSource of multiple layers in multiple mxd's

I looked on all of your sites and did not find a solution to my problem. Almost all of our data has been copied to an SDE and now most of the layers in all of the mxd's need to be redirected to the ...
2
votes
1answer
135 views

Area in KM from Polygon of coordinates

I have polygons from coordinates in (python shapely) that looks like this POLYGON ((24.8085317 46.8512821, 24.7986952 46.8574619, 24.8088238 46.8664741, 24.8155239 46.8576335, 24.8085317 46.8512821)) ...
2
votes
0answers
23 views

Help getting a Mathematical Representation within a Layer's Attribute Table

I'v been playing around with Vector Coding and was wondering if there was any Plugins out there that might let me represent Vectors within a layer as it's Mathematic attributes in the Layer's ...
2
votes
0answers
49 views

Passing Value for Dictionary Look Up in Field Calculator fails [closed]

I've a field calculator that I am trying to use that uses a csv file to look up appropriate value based on key that is passed provided to the function. As provided below, the only values calculated ...
2
votes
1answer
109 views

Access ArcCatalog Window through ArcPY

I want to create a button in ArcCatalog that takes the metadata from the selected file in ArcCatalog and prints it to a text file. The metadata extraction part is done, and I have succssfully tested ...
2
votes
0answers
69 views

Help with Python/GDAL documentation

The instructions from the url http://gdal.org/gdal_tutorial.html give the following example: dataset = gdal.Open( filename, GA_ReadOnly) with the following description: It's interpretation is ...
2
votes
0answers
232 views

Iteratively exporting from Table to .txt in Model Builder (ArcMap) not appending correctly

I am solving a location-allocation type of problem where I use a loop to go through several specifications of the problem. The model runs fine, and produces the vizualization outputs just as expected. ...
2
votes
0answers
61 views

Programmatically Harvest and Disapprove Metadata - GeoPortal Server

Is it possible to synchronize an existing metadata catalog in esri's GeoPortal Server? I have access to the server, and have a script to add an XML file to our web accessible folder. After this script ...