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

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7
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139 views

gdalwarp producing empty rasters when called from python script, but not via command line

I'm trying to aggregate some raster data (all .tif) up to a coarser resolution (from .05 degree to .25 degree) using gdalwarp in python, but the command is not working. Instead of getting an output ...
7
votes
0answers
99 views

How to access a deleted features attributes (before committing)

I have a signal setup for a feature deletion event on a layer: self.layer.featureDeleted.connect(self.feature_deleted) When I try and grab an attribute from the deleted feature on the slot, a ...
7
votes
0answers
632 views

ArcGIS Cost Path Analysis - How Is Arcpy Cost Path Analysis Tool So Much Faster Than ArcObjects

Although I love slinging some python to create geoprocessing scripts/services, I was under the impression that using ArcObjects to do the equivalent operation(s) will have better performance. I've ...
6
votes
0answers
700 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 ...
6
votes
0answers
675 views

How to get rpy2 for QGIS on OSX?

I am a new QGIS user, have installed QGIS on a Mac running Snow Leopard OSX 10.6.8 following all the instructions. QGIS seems to work well for everything other than when I boot up I get the message ...
5
votes
0answers
461 views

RGB satellite image in Python with Basemap

Can anyone recommend a workflow or python library that will let me work with RGB images and BaseMap (or something equivalent - could be CartoPy). I have Landsat 8 images, and can load one in python ...
5
votes
0answers
80 views

Is it possible to add an ArcGIS attachment to a row in Oracle using oracle stored procedures?

So far I have been able to attach files to features within a featureclass using the python tools and ArcObjects. Within Oracle I have been able to add features with geometries using the ST_Geometry ...
5
votes
0answers
94 views

Diminishing performance of gdal_polygonize in a python subprocess for GRASS to PostgreSQL

I have written a python script to polygonize GRASS rasters into a PostgreSQL database using the gdal utility gdal_polygonize: sub.call('gdal_polygonize.py -8 gdb/quercus/{0}/cellhd/{1} -f ...
5
votes
0answers
271 views

Performing buffering and intersection with script in PyQGIS

I wrote a script that performs the intersection of two layers: The first Layer -> layer1, represents the rivers The second Layer -> layer2, represents a set of circular dots distributed in a ...
5
votes
0answers
279 views

QGIS: How to reverse vertex ordering in polygons

I am working with an Oracle spatial connection in QGIS through which I am accessing and editing a vector layer. I find that when I edit a geometry, the vertex ordering is reversed (to clockwise in the ...
5
votes
0answers
154 views

Distribute QGis plugin which depends on certain Python packages

I developed a plugin for Qgis which depends on some Python packages. On Linux and Mac, this is not really a problem because I can easily install them with the system pip command. Windows is another ...
5
votes
0answers
449 views

How to convert a raster (array) to a NetworkX graph and do a * search?

I want to use a slope-raster for a a_star path analysis in NetworkX. I am using Python for this project. My test raster looks like this First I read in the raster with GDAL input_raster = ...
4
votes
0answers
33 views

How to unproject a UTM ESRI Shapefile over WGS84 extent boundaries

Background: I am working on a collaborative project in Python that uses GDAL/OGR to work with rasters and vectors. There is one function that attempts to project one ESRI Shapefile's coordinate ...
4
votes
0answers
32 views

Custom forms feature in QGIS: QMessageBox.warning closes QDialog as well

I am attempting to work with custom forms in QGIS. I have included a validate function in my code that will pop a QMessageBox() if the validation fails. My problem is that when I close the QMessageBox ...
4
votes
0answers
21 views

“Merging” 2 layers of LineString with splits at intersections

I would like to "merge" 2 networks of lines and these lines need to be split when they intersect. With pictures it should be clearer : What to do: if a black line intersects a red line, they ...
4
votes
0answers
29 views

What's the binary format of ENVI (Classic) ROIs?

I'm a (lonely) Pythonist in an office full of ENVI/IDL users. I've created some tools to help bridge the gap, but one big stumbling block is ENVI Classic .roi files, which my colleagues use a lot. I ...
4
votes
0answers
102 views

Counting features into intersections of Shapely Polygons

I have a geopandas GeoDataFrame containing hundreds of shapely Polygon and MultiPolygon geometries. The polygons overlap in lots of places. I'd like to make a new geometry that contains a count of how ...
4
votes
0answers
447 views

Geometric Network for Electric Utilities

I'm not expert in the use of geometric networks nor in Python scripting and I need help with the following problem. I'm using ArcGIS 10.0. I have defined a geometric network for an electric ...
4
votes
0answers
439 views

Extracting x,y,z values from a postgis linestring to python using ogr

I am trying to load a postgis linestring into python (using ST_DumpPoints) and extracting x,y,z coordinates, which is working but extremely slow..and if i mean slow, i really mean it (yes, it takes ...
3
votes
0answers
56 views

Python script to automate saving satellite images for different combinations of lat longs

PS. : This is my first try at a GIS application. Please forgive if my question is pedantic. I would like to get a series of satellite images all at the same scale centered around different points on ...
3
votes
0answers
29 views

How to fill composer map with canvas data and export composition as png using Python script in QGIS

I'd like to create a Python script in QGIS that will take some data (shp + tif, in my example), use tamplate Map Composer (from a file) and export created composition to a png image. With almost no ...
3
votes
0answers
37 views

Resampling netcdf file

I have several years of precipitation data from CHIRPS that has a resolution of 0.05 degree. I'm currently working on a recharge script that has static data resolution of 0.01 degree. I'm trying to ...
3
votes
0answers
50 views

Can qgis_core work with external python distribution (such as Anaconda)

I've built a python application that has its own GUI. I am trying to use qgis.core/pyQgis as map display only. Specifically, i have anaconda 2.3 and its python distribution (2.7.11). After research on ...
3
votes
0answers
43 views

matplotlib show() suspends ArcGIS

I've written a python script to plot a cross-section from a DEM along a line. Everything works fine except when I Show the plot, ArcGIS hangs and I have to force it to close with Task Manager. I ...
3
votes
0answers
40 views

SQL SERVER 2012, Python subprocess, OGR

Need help with uploading shapefile with srid 102008 to SQL server 2012. I ran the ogr2ogr script in the ogr shell and it uploaded the shapefile within seconds but when I try using python subprocess to ...
3
votes
0answers
24 views

How to use pythons' GeoAlchemy2 to filter on dynamically generated Points?

I'm trying to do something like this SQL query in Geoalchemy2: SELECT district_polygons.district FROM markers, district_polygons WHERE ST_Contains(district_polygons.multi_poly, ...
3
votes
0answers
36 views

How to show only selected features from a a layer in the QgsComposerLegend?

I have developed a custom qgis plugin. I have a button to export the map canvas in the form of image along with the legend. I came up with the following code for the legend: legend = ...
3
votes
0answers
61 views

spatial index intersection with qgsrectangle only computes polygones

I have the problem, that i only get polygon features inside my defined rectangle. If i switch off my polygon layer(s) i get my lines. TOC: Line-Layer on, Polygon-Layer on: i only get Polygons which ...
3
votes
0answers
85 views

Dissolving polygons in a large dataset

I need to dissolve polygons by the ID attribute in a large dataset (+-1gb shapefile). I have been struggling to find an efficient method to do this. I have tried the following methods: Postgis ...
3
votes
0answers
163 views

Folium heatmap not displaying

I have an output file data.json [{"5403": 2, "9734": 1, "2565": 5, "5087": 2, "9061": 1, "1761": 4, "4811": 7 "1111": 5, "3891": 3, "1962": 3}] and a shapefile converted to geojson ...
3
votes
0answers
80 views

Creating arc segment between two points with common field using Python?

I need to create Arc Segments between multiple points with like data using half the distance between the two like points as the radius of the arc segment. I would prefer to use python to ...
3
votes
0answers
135 views

QGIS 2.8 Python Plugin Unittest Segmentation Fault 11

UPDATE: This issue may be isolated to my MacBook. The seg fault did not occur in testing on Windows. I have put together a sample unit test for a QGIS python plugin. It is causing a Segmentation ...
3
votes
0answers
78 views

Publishing a geoprocessing service that imports modules besides arcpy?

I'm trying to publish a geoprocessing service (10.2.1) that will be used to generate a PDF from a webmap using an MXD layout as a template. The problem is that if I try to import any module besides ...
3
votes
0answers
119 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 ...
3
votes
0answers
192 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, ...
3
votes
0answers
556 views

Connect to QGIS 2.6 Python Plugin function via button on custom feature form

I am trying to connect to a QGIS 2.6 Python plugin function via a custom feature form button. On my feature form, I'm attempting to do a few things : enable the updateButton only if the ...
3
votes
0answers
109 views

Lining attributes up with features when creating shapefile using PyShp?

I used the Python Module Pyshp to select particular census blocks from the Census's shapefiles and package these into a single shapefile. However when I add this data into ArcMap and right click to ...
3
votes
0answers
94 views

point feature to raster with count of unique points

I am using ArcGIS 10.1 with Python 2.7 I have a point layer with thousands of points that each hold an id value of its owner. One owner can have multiple points, meaning that points can have the same ...
3
votes
0answers
32 views

Action: Move pointfeature to other layer - Point becomes Multipoint

I'm trying to write an action that moves a pointfeature from one layer to another. It works fine until i try to save the layer with the new feature on. He says he can't save a MULTIPOINT to a ...
3
votes
0answers
120 views

arcpy.mapping.ExportToTIFF fails to render layer?

Has anyone else had this problem? I have an mxd file with two layers in it, one of which is fairly 'heavy' (i.e. takes a minute or so to draw). All layers are visible by default. I have the ...
3
votes
0answers
403 views

How to convert length in Decimal degrees to meters programmatically?

I'm new to qgis and I want to find the length of some roads in a map. So I used the following code, from shapely.wkb import loads def getLength(): layer = ...
3
votes
0answers
327 views

How to use Python's subprocess module in a for loop ArcGIS?

I am new to scripting with ArcGIS. Although this might be an easy thing for those that know Python well, I haven't figured out how to use the subprocess module in a script. I actually think I'm ...
3
votes
0answers
80 views

Overriding the QGIS Feature Dialog

We are developing a QGIS plugin and would like to override the QGIS Feature Edit Form with our own Dialog. Have explored using setEditForm and setEditFormInit, but the init process appears to want to ...
3
votes
0answers
119 views

How to compute (X,Y,Z) of a point from given attributes

Is there a way to compute the geodetic coordinates (Earth Centered) of a satellite S(x,y,z). The original problem is to compute the footprint of an antenna, given the following information: ...
3
votes
0answers
190 views

Create vector grid from canvas using script

I've modified "Hex grid from layer bounds" script to my need. Just added cellsizex and cellsizey. Changed the hexagonal - 3 to "1" to make it as a square grid. Is it possible to include an option to ...
3
votes
0answers
80 views

ArcPy: Initialize zero valued grid Raster and iteratively increment

I'm jumping right into ArcPy to help out a friend who needs to automate some ArcGIS work. The problem at hand can be reduced to the following pseudocode: accumulationRaster = SomeZeroedRaster for ...
3
votes
0answers
472 views

QGIS API - Print Composer Template produces empty map?

I have a print composer template which I'm trying to populate with different subset queries from a CSV-derived vector layer using the Python API. However, all the output PDFs contain everything except ...
3
votes
0answers
82 views

How to find the minimum number of inspection points?

I am working on a pipeline inspection project and there is a high liklihood that some inspection tool deployment/retrival station will need to be installed on the pipe network. the problem is ...
3
votes
0answers
101 views

Arcpy in Python Plugin for SPSS

Is it possible to run the arcpy module in the Python for SPSS plugin to run the search and update cursors?
3
votes
0answers
154 views

PyQGIS: How to color raster layer with existing colorBrewerMap

With pyqgis I have added multiple new raster layers to the legendinterface(). Because i like the ColorBrewer style i want to color some of them with the "Spectral" gradient. How can I do this in ...