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

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1answer
21 views

Raster image thresholding using python

I would appreciate if someone could guide me for applying thresholding technique to input raster image using Python. I intend to extract impervious surfaces from a high resolution raster such as ...
15
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6answers
6k views

Generate points that lie inside polygon

I have polygon feature and want to be able to generate points inside it. I need this for one classification task. Generating random points until one is inside the polygon wouldn't work because it's ...
2
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2answers
26 views

How to calculate field as a substring of another?

I have a text field, field1, that's populated with 14-digit identifiers, like "01234567890123". I create a new field, field2, that I want to show the first four digits of field1. I would like to do ...
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0answers
12 views

How to write a QGIS-plugin to be used in IntraMaps Roam 2.4.0?

I know some python, but I have never written a plugin for QGIS nor Roam before. I like to be able to turn layers on/off in Roam I have read the Roam's wiki, and I have managed to make a plugin called ...
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3answers
3k views

Replacing NULL values in geodatabase table?

How do you update NULL values within a geodatabase table using the ArcGIS Field Calculator (service pack 4) without changing other values to NULL? I've tried the suggestions on this previous ...
4
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1answer
236 views

How do I link OGR with spatialite?

Problem & Evidence: I'm trying to create a spatialite file with the code snippet below. However the outDataSource object gets assigned NoneType and all subsequent (unshown) code fails. I'm ...
13
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1answer
2k views

How to make a separate Python installation that can call ArcGIS' arcpy?

I see a lot of threads asking how you can create a separate Python installation (e.g. the Anaconda or Python XY distribution) that can use arcpy, while not 'breaking' the original ArcGIS python ...
2
votes
1answer
38 views

Looking to find (or build) a particular Python geoprocessing tool

So here is my situation: There is a large area (a wildlife refuge) of nearly 200,00 acres that we have loads of spatial data for, from habitat management projects from the past several years. My boss ...
5
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1answer
75 views

Cutting a circular buffer via Arcpy

I am currently working with compressor stations on centerline routes. These compressor stations have a 3 mile buffer surrounding them. I wish to cut a portion of the circular buffer off. These cut ...
2
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1answer
18 views

How to split name in label so only first two words appear?

The labels for my feature SSA_NAME are approximately 5 words long. I would like to shorten the labels to only 2 words. Every time I try a different code I receive either an error message or my layer ...
2
votes
2answers
514 views

Union multiple shapefiles with overlapping shapes

I have several shapefiles that overlap and I would like to union their geometries to get rid of those overlaps. I know how to do this with OGR and Python for single geometries. from osgeo import ogr ...
1
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0answers
25 views

Minidump on exit in QGIS (2.8.2- Wien) 64-bit version when using GDAL in plugin

I am working on a plugin for QGIS that is working fine on 32-bit versions but I am having some problems while using it on the 64-bit standalone installation package. I have tried on several machines ...
1
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1answer
46 views

If/then python for classifying existing field values to a new field

I'd like to have a tool or quick python script to classify an existing number field to a new text field. For example I have a roads layer that has a type identifier as a coded number and I would like ...
2
votes
2answers
36 views

image segmentation of RGB image by K means clustering in python

I want to segment RGB images for land cover using k means clustering in such a fashion that the different regions of the image are marked by different colors and if possible boundaries are created ...
0
votes
0answers
19 views

How to call the Qt UI of a script?

I'm pretty new in the python world, and I'm working with the python console inside QGIS (Master version on a Debian machine). I have written some scripts, all of them are in the same directory (e.g. ...
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0answers
30 views

Changing colours in a simple shapefile

I have a very simple map (http://www.nyc.gov/html/dcp/download/bytes/nybb_15b.zip) and I have never before worked with shapefiles in any way. Can someone tell me what I need to do in order to change ...
1
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1answer
20 views

Gdal ReadAsArray() different values than gdal band statistics

I am confused about why if I open a band with GDAL I get, for example, band.GetMaximun(): 1000, but if I do ReadAsArray I get myArray.max(): 1200 (the same if I do np.max(myArray)). Does someone knows ...
1
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1answer
105 views

Restrict text widget to only integer between 0 and 999 in IntraMaps Roam

I have created a form and added an attribute as a Text widget in the Roam manager. Now I'm trying to restrict the input to be an integer between 0 and 999. I want the field to stay "empty" (or ...
2
votes
1answer
24 views

Error: Algorithm not found (QGIS)

I wrote the following code using QGIS'API. import os from qgis.core import * import qgis.utils prefix_path = os.environ['QGIS_PREFIX_PATH'] QgsApplication.setPrefixPath(prefix_path, True) ...
3
votes
2answers
213 views

How to delete column/field in PyQGIS?

How to remove or delete column fields in a shape file using python?
1
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0answers
45 views

Using gdal_merge to merge a large amount of files (in pairs)

I'm new to python and how it can be applied to gis. I have a large amount of MODIS files to go through and I've already extracted, reprojected and converted to GTiff the bands that I need from each ...
2
votes
0answers
20 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 ...
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0answers
12 views

PyQGIS Standalone Crashes python.exe when zooming out too far / Process finished with exit code -1073741819 (0xC0000005)

I have the following PyQGIS Standalone App which is working fine so far. One little problem is that if I zoom out to the MaxExtent(by scrolling the mousewheel) the app crashes python.exe so that the ...
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0answers
20 views

rasters written with gdal show up with units of meters when they should be degrees

I have some SMOS soil moisture data packaged in a netcdf format distributed by "cp34-bec". I have been able to use GDAL to extract this data as a raster layer, using a projection i think is ...
2
votes
1answer
18 views

Redirect remote shell command output to ArcMap geoprocessing tool display?

I have a Python script that runs a shell command on a remote server (using the Fabric module). When I run the tool in the debugger, I see all the output scrolling, as the command can take hours to ...
0
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0answers
17 views

why did my python mysql script stop working, with error on fetchone()?

This code was working a couple weeks ago, then without changing anything, it started throwing an error. Here's the code: #Query climate table sFrom = dateIncrement.strftime("%Y-%m-%d ...
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1answer
26 views

Python: how to set a different output folder

I want to transform some vectors to rasters in my folder but I have difficulties setting the output folder. The following code only allows me to output to the original database. I hope to output all ...
1
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1answer
45 views

“Browse” button returns python error in QGIS

I use the latest version of QGIS (2.8.2) in MAC and have se the default Python version 2.7. Moreover, I have installed all the required python modules and GDAL. It was working before, but now, when I ...
2
votes
1answer
30 views

How to add a message bar to custom canvas?

There is a simple code to add message bar to main window in QGIS: iface.messageBar().pushMessage("Hello","World") My question is how to add bar to my custom canvas canvas = QgsMapCanvas() in ...
2
votes
2answers
63 views

QGIS/Python script to generate random points many times

Good day. Can anybody provide a simple code to be run in the Python Console of QGIS (I am using 1.8 Lisboa) to generate X number of random points (say e.g. 5000) over a certain global shape of ...
0
votes
2answers
428 views

Arcpy SelectLayerByAttribute_management where_clause with LIKE not returning like values

I am selecting 2 intersections from a shape file using info from a File Geodatabase Table. The values are very similar as shown in example at the bottom. I am using a LIKE in the statement but it is ...
1
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2answers
69 views

Trouble importing NumPy in GRASS. Architecture

I can't get GRASS to work on my system, and after doing some digging I think it is related to me using 64-bit python. I'm not really sure. I get this message... This module requires the ...
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0answers
20 views

Extracting pixels latitude into new raster [on hold]

when extracting pixels latitude into new raster the boundary not matched, what shal in do? # -*- coding: utf-8 -*- #!/usr/bin/env python print("Started\n") import gdal import numpy as np ...
2
votes
2answers
438 views

Python problem visualization .tif image

I am trying to read a hyperspectral image in Uint16 .tif format and visualize it. I use GDAL in Python to read the data and everything works perfectly when I use matplotlib to show one band of the ...
1
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0answers
18 views

import qgis.core problem with QgsFeature and QgsGeometry ImportError: DLL load failed: The specified procedure could not be found

I've tried several previous answers to similar questions - no luck. I've tried everything, nothing seems to work. This is the error I'm getting Traceback (most recent call last): File ...
1
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1answer
152 views

geotiff conversion to coordinate system with gdal

I would like to get the coordinates X Y Z from a geotiff file. I am using the gdal translate for the conversion. Which output format is the more adequate for containing a 3 numpay array X Y Z ?
0
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2answers
54 views

Remove first seven characters from field string using Field Calculator

I wrote an expression/codeblock that removes the words "Nearby:" from the field value string if it has it. Codeblock: import string def splitme(s): if s[:7] == "Nearby:": aList = ...
-4
votes
1answer
70 views

Handling ArcPy locks in Python script?

i am writing script which uses different Tools of arcgis and implementing different functionalities .. My script consists in different Functions running in an order. Each function is connected to ...
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0answers
13 views

Pythonw has stopped working when running arcpy.SubsetFeatures_ga

I'm currently trying to subset a shapefile into training and validation files. When I run the following line of code, python crashes. I'm using ArcGIS 10.1. arcpy.SubsetFeatures_ga(current_shapefile, ...
1
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1answer
67 views

How to register “events” for linear referencing in pyqgis?

Is there an easy solution for recording events for a line crossing borders of zones in a polygon layer? I need to implement this in python using QGIS, thus pyqgis. The image attached illustrates what ...
0
votes
1answer
776 views

OSRM API - nearest point fed into routing

I am using the OSRM API to (1) determine the nearest point on a road segment from a give random point with http://server:5000/nearest?loc=_lat_,_lon_ The returned coordinates are used then as an ...
2
votes
1answer
32 views

PyQGIS standalone script does not work. Error “QGraphicsScene::addItem: item has already been added to this scene”

I try to test a PyQGIS standalone script which should just show one Shapefile. Sounds pretty simple but does not work. Here is my script: from PyQt4 import * from PyQt4 import * from PyQt4.QtCore ...
0
votes
1answer
16 views

Semi Automated Classification plugin (QGIS) error when trying to create ROI

When I try to create a new ROI through Semi-Automated Classification plugin (SCP) for QGIS, I keep getting a message saying: "It appears that SciPy is not correctly installed. Please, see this page ...
2
votes
1answer
19 views

problem deleting shapefiles because still in use by arcpy cursor [duplicate]

I have a function outputTblContents which contains def outputTblContents ( path ): rows = arcpy.SearchCursor(path, fields="alpha; beta") for row in rows: print("{0} => ...
0
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0answers
22 views

Is it possible to save a dxf in memory

Following on from my question here, when I run the ExportToCAD tool arcpy.ExportCAD_conversion(listOfLayers, formatRelease, location + fileFormat, "Ignore_Filenames_in_Tables", ...
1
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1answer
172 views

How to select and zoom in features from a QGIS Python Plugin

I'm very new to Python. I'm trying to find a way to select and zoom to the features from a QGIS layer. I've created a plugin and built a custom form. I have 3 values from the form which I need to ...
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2answers
45 views
3
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1answer
183 views

ArcGis Python Security Concerns

I’m working for a large organization which are using ArcGis Desktop on some (windows) clients. The security requirements for the system is very strict, and a part of that is prohibiting the users the ...
1
vote
1answer
37 views

Setting PYTHONPATH for compiled QGIS version on Linux

I'm trying to set the PYTHONPATH in order to be able to load the qgis classes in a python console (not the QGIS Python one). I followed some resources I've found (PYQGIS Cookbook, and others) but I ...
2
votes
1answer
116 views

smallest, lossless, GDAL ready image format

I would like to know what the smallest file format is I can use with GDAL that fulfills the following criteria: lossless compression (relatively) easy to read/write with GDAL Python bindings least ...