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

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Python GDAL API: .Transform(osr.CoordinateTransformation(…), …)

A have input .tif files and geojson with different EPGS. I'm trying to use osr.CoordinateTransformation(source, target) method which takes 2 arguments of EPGS like on this cookbook. So how can I get ...
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55 views

NumPy to GeoTiff for use with Gdal

I have a few NumPy arrays: lat, lon, and 6 data bands. I'd like to convert these to GeoTiff and then apply the gdalwarp function, based on a specific projection, to each band. Is there a standard way ...
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1answer
40 views

Convert and plot python basemap and netCDF file in UTM zone 45N

I have a netCDF file with precipitation output for one year. I have a problem with aligning the basemap and netCDF file, and plot them in the same coordinate system. The netCDF file covers the ...
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2answers
4k views

How to draw polygons from the python console?

I've been visiting and revisiting the page on geometry handling in the PyQGIS Cookbook: https://www.qgis.org/en/docs/pyqgis_developer_cookbook/geometry.html but can't seem to figure out how to get the ...
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2answers
38 views

Add a geometry in sqlite in pyqgis

I'm trying to create a geometry column in a table which I created. I found the following code: cur.execute('SELECT addgeometrycolumn(%s, %s, %s, %s, %s)' %(table_name, geometry_column_name, EPSGcode,...
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1answer
1k views

How to label vector features programmatically?

I am using python for QGIS 2.0.1 and I have a vector layer of points representing the positions of state labels. I want to display the 'state abbreviation' attribute on the corresponding point for ...
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30 views

How to access qgis module from my virtualenv

I am running an Ubuntu 14.4 and I have installed a python virtual environment. Then I pip installed several python libraries (gdal, lxml, psycopg2 etc.) Also in my system I have the module for qgis. ...
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2k views

Help with PostGIS polygon geometry - non-closed rings

I've picked up a copy of the super-wicked book 'Python Geospatial Development' by Erik Westra (Amazon link), and I'm working through it. Currently, it's teaching me to load GSHHS coastline data from a ...
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1answer
53 views

Can the JSON output for an ArcGIS Rest Server be opened in a similar way to a WFSServer?

I would like to construct a python script to obtain JSON vector data from the following ArcGIS Rest Server: http://maps.six.nsw.gov.au/arcgis/rest/services/sixmaps/LPIMap/MapServer/69 For a ...
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0answers
144 views

Accelerating python looping process for A-star path finding on DEM surface?

I try to make an A-star Path Finding program base on tile-graph (image raster data as graph) where each pixel values represent as cost and elevation.. In my case, DEM raster data was called by using ...
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2answers
67 views

Angle at intersection point from two Lines

I would like to find the angle of two lines at their intersection point. In my opinion it is the azimuth I'm looking for, right? So I'm using Python with shapely for finding the intersection and ...
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41 views

Read a vector layer from a Postgres/PostGIS database via a SQL query with QGIS and ogr in a python script

I have a treatment table for different aggregation stategies on a geospatial table in a PostgresSQL/PostGIS database. The aggregation strategies addressing temporal and species specific pre-selections ...
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0answers
35 views

Is there a faster process to update one column for all features?

I have written a python script in QGIS which estimates the amount of residents for each building polygon by using census block data and building polygons (about 500 000 buildings in an area of about ...
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1answer
483 views

Python script for dark object subtraction on Landsat 8 Imagery

Does anyone know of any python scripts that will allow me to conduct such a process? I am limited to open source software and have minor experience in Python.
2
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1answer
121 views

Longest Common Subsequence for trajectory matching in Python

Is there any fast implementation of the Longest Common Subsequence algorithm for trajectory matching in Python? Ideally it would work with trajectories of different length in 2d spaces.
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25 views

Enable LSCV kernel density estimation for Animove in QGIS?

I am currently studying primate home range behaviour and I want to create a kernel density utilization distribution based on the least-squares cross validation bandwidth parameter (LSCV), as some GPS-...
5
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2answers
205 views

Optimizing Python GDAL ReadAsArray

I am using the GDAL ReadAsArray method to work with raster data using numpy (specifically reclassification). As my rasters are large, I process the arrays in blocks, iterating though each block and ...
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2answers
1k views

Link QGIS to Anaconda Python Distribution: Spyder, iPython Notebook, pip, scikit-learn

I have Anaconda as my primary Python distro, and want to route Python related QGIS scripts through it. With Anaconda, I have Spyder, can easily install packages with pip, and can launch a iPython ...
2
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1answer
187 views

AttributeError: 'module' object has no attribute 'classFactory'

I'm trying to compile a cython plugin for QGIS. The plugin is working on windows (32/64) machines but was never used on Mac before. I compiled the cython for python as described here but there are ...
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0answers
13 views

Return raster that intersects another raster in gdal

I'm trying to programmatically orthorectify a bunch of Rasters (.ntf format), however I need a DEM that covers each raster in order to do so. I have DEM rasters (.tif) as tiles that cover the entire ...
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1answer
59 views

Calculate centroid of a point cluster

Having this function that inserts locations in a database: def insertLocation(cur, label, point): print label cur.execute(""" SELECT label, centroid, point_cluster ...
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1answer
64 views

QGIS Python Script - Python.exe Stopped Working

I purchased this book called Building Mapping Applications with QGIS and I am trying to work through one of the exercises. There is one script that I try to run that crashes python, generating the ...
5
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1answer
204 views

Generating surfaces of different heights from LIDAR points

I am seeking a way to generate surfaces (polygons in a 3D space) of different heights from LIDAR point clouds, whose spacing is 4 points per square meter. The typical application is like roofs, which ...
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45 views

Python QGIS crashes within categorized renderer setup

I'm hassling around with QGIS renderer definitions in python with QGIS 2.8 at debian wheezy. At least I want simply build step by step a categorized renderer to fill a polygon. The script crashes, ...
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39 views

How to interpolate raster data using computer vision (OpenCV)?

Background A raster file collected via LIDAR records the topography of a watershed. To properly model the watershed, the river must appear continuous without any breaks or interruptions. The roads in ...
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2answers
84 views

GDAL python cut geotiff image with geojson file

I wrote the function which cutting geotiff image by bounding box. First image is original. At second you can see result off my code. I don't use gdalwarp or any console utilities. But I have no idea ...
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1answer
949 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 ...
3
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2answers
971 views

Using arcgis.rand() with variables from code block of Calculate Value tool?

Within a larger ArcGIS ModelBuilder model I am trying to populate a field in an attribute table with a random number, using Calculate Value. The overall distribution of random numbers needs to follow ...
2
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1answer
57 views

Add multiple rasters using QgsRasterLayer with for loop

I am trying to create a for loop for coloring up multiple rasters simultaneously. I am able to do it for one layer, but trying to implement the for loop to do it for more than one layer is proving ...
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1answer
63 views

How to burn geometry to raster without shapefile, just from list of coordinates?

I have a list of coordinates points(x,y) of some multipolygon like this: [[x1,y1][x2,y2][x3,y3] ... [xN,yN]] Also can convert between lat/lon and UTM coord systems. When we use gdal.Raesterize like ...
6
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1answer
8k views

Python GDAL: Save array as raster with projection from other file

I have an array of data, and for each datapoint I know the latitude and longitude. I'd like to save it as a GTiff with the same projection as other rasters I have. This is what I've tried so far, but ...
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21 views

gdalwarp not clipping VRT to correct extent

I'm trying to clip a projected .vrt raster to an extent expressed in GCS coordinates and it's not doing what I would expect. Here is my command: gdalwarp -te -133.08813624 56.69042536 -132.69405069 ...
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2answers
3k views

Raster Calculator Workaround in Arcpy for Suitabiliy Analysis

This is my first attempt at a complex stand alone python code. I am self teaching the arcpy module, well at least attempting to. I am having a great deal of difficulty getting my site suitability ...
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1answer
516 views

Error in Select Numeric type column in pyodbc with ArcCatalog?

I created a python script that uses "pyodbc" plugin to connect a SQL Server database and write out data. It was imported in an ArcGIS 10.1 tool and run from there. try: arcpy.AddMessage('FLAG 0') ...
2
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1answer
562 views

How Can i create a Vector layer from selected features qgis

In my qgis plugin i select dynamically features from a Vector layer. and currently i create a new layer from selection on combining all feature into a new feature: theField = QgsField self.theString =...
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59 views

how to create geometry type(point,line,polygon)on esri personal geodatabase*.mdb?

Qgis can not read geometry type on ms access*.mdb's table connecting with esri personal geodatabase *.mdb? This can open as test file, but unknow geometry type. Point can create using with "point ...
2
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1answer
59 views

How to set “draw line inside polygon” using Python?

In the QGIS properties of a layer I want to activate "draw line only inside polygon" for a specific layer, but using Python. I don't want to use the GUI for it. Can this be done? I set the line ...
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0answers
27 views

Is there a Python equivalent to QGIS Raster Calculator's “file1.asc” AND “file2.asc”

I would like to script a calculation equivalent to QGIS Raster Calculator's "file1.asc" AND "file2.asc". I have 18 data raster files which I would like to do the equivalent of ADD to each of five ...
1
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2answers
102 views

How to read geographic coordinates when the Shapefile has a projected spatial reference

I have a polygon Shapefile and want to read the polygon's vertices using OGR and Python. The reference system of the file is projected. However, for further processing I need the geographic ...
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1answer
251 views

Can't get the correct version of GDAL installed to use ReadAsArray without getting error in Python

Using the instructions here . . . https://pythongisandstuff.wordpress.com/2011/07/07/installing-gdal-and-ogr-for-python-on-windows/ I downloaded the following files: GDAL-1.11.1.win-amd64-py2.7.msi ...
3
votes
6answers
4k views

ExportToJPEG() arcpy script failure

I'm attempting to writing a python script that will automate exporting a set of stock maps to JPEG from their mxd files, and I'm having some strange issues getting there. I've alternatively been ...
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2answers
2k views

Automating batch load of multiple GPX files into PostGIS

I've got 50+ GPX files that I would like to "batch load" into a PostGIS database. All of the track_points data would be loaded into a "track_points" table (with typical GPS fields like lat, long, ...
0
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1answer
988 views

ArcPy SelectLayerByAttribute Error and how to control GP output layer name

I have a rather long script that first references an SDE feature class (non-versioned) to perform an attribute selection based on a SQL selection. I've been unable to figure out why the script will ...
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34 views

How to implement a Plotting widget into already existing PyQt4 Interface

I am using Python, PyQgis for about one week and already built a plugin for GIS 2.14 which is -so far- working pretty well. As my next step I want to add a widget to plot data to my already existing ...
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1answer
51 views

QGIS: startup.py executed twice?

To test something I have a very simple startup.py file in my .qgis/python folder: import qgis qgis.utils.iface.actionShowPythonDialog().trigger() print "Welcome chump" Python console launches fine,...
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1answer
109 views

How to define border colour for rule-based style using PyQGIS?

I use the following to create a Rule-based style for a given layer which includes defining a label, expression and colour fill: from PyQt4.QtGui import QColor layer = qgis.utils.iface.activeLayer() ...
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2answers
1k views

How to remove all selection from all registered layers using QGIS plugin?

I want to remove all selection from registered layer in QGIS using Python. I tried to clear the map canvas using: self.iface.mapCanvas().clear() self.iface.mapCanvas().refresh() but the ...
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1answer
40 views

SAGA GIS work with python API error

I want to work with python API and SAGA GIS. I am very new with this work. The first step I find one module for example Slope, Aspect, Curvature and I take with right click one python script. python ...
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0answers
53 views

How to handle large tables in QGIS using python?

I'm currently writing a plugin that calculates values based on a QgsVectorLayer's attributes. To display and print the values I'm using a QgsComposerTextTableV2. I have several problems with my ...
2
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1answer
268 views

Plugins crashing with “No module named qgsprojectionselectionwidget” in Windows?

My Python QGIS plugin works on Ubuntu (at least for me, and all fatal bugs reported so far are solved), but when I run it on QGIS installed from the official 2.10.1 64-bit installer for Windows (on ...