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

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3
votes
2answers
153 views

How to determine number of features in GeoJSON file using Python or JavaScript?

Is there a best way to determine the number of features in a GeoJSON file? Ideally using Python or JavaScript.
1
vote
1answer
59 views

How to export only certain column from selected feature to csv file in QGIS using python code

I have selected features in QGIS, I want to export only two columns from the selected features to a csv file automatically using python code. I have tried the following code: layer = ...
2
votes
1answer
30 views

Does mapCanvas().refresh() not work in QGIS 2.6?

Before I used the function qgis.utils.iface.mapCanvas().refresh() to reload the map canvas after for example a layer color was changed from a plugin. But this is not working with QGIS 2.6 for me. ...
2
votes
1answer
85 views

ArcGIS Python syntax error using nested if else

I am trying to use the field calculator in ArcMap 10.2 to fill an empty field based on the contents of two exiting fields usint this python script in the Pre-Logic Script Code. def ...
-1
votes
0answers
9 views

Integrating GIS with HDM4 software

what kind of a programme could be developed to integrate the HDM4 Software (Highway Development & Management) with the GIS??
1
vote
0answers
19 views

Raster Vector stack

I want clipped image of NDVI for a particular area. I did raster calculation for getting the image with NDVI values. After that I tried extraction function clipper. In this function we have to use two ...
2
votes
2answers
532 views

Using reader Feature Type Name as Writer Feature Type Name in FME

I've search and searched for a way to do this, but no method seems to work. Basically I want to use the input feature class name (feature type in FME) as the output name. This normally works, ...
0
votes
0answers
30 views

Polygon of Voronoi cell using scipy.spatial?

I have points (e.g., lat, lon pairs of cell tower locations) and I need to get the polygon of the Voronoi cells they form. from scipy.spatial import Voronoi tower = [[ 24.686 , 46.7081], [ ...
-1
votes
1answer
57 views

Unable to merge two shapefiles (created from text files) using ArcPy? [on hold]

I am trying to merge 2 shapefiles together created from 2 text files. I am new to python and managed to get the textfiles into shapefiles, however, when trying to merge the two newly created ...
1
vote
1answer
41 views

Problem with tool validation script in ArcGIS?

I have tried to write some validation code for a script in ArcGIS. This validation code more or less repeats what the script itself does, which is a simple cutting up of a long string by using the ...
1
vote
2answers
62 views

QGIS Deployment in Citrix XenApp - How to Remove Pyramids from the image “properties”

I'm working on deploying QGIS 2.4 into a XenApp 6.5 desktop environment. We've tested QGIS to see if it will run in our environment on a test server and have found that building Pyramids with ...
3
votes
1answer
57 views

Using “Raster to Other Format” Conversion Tool (BIL file to TIFF file) in ArcGIS for Desktop?

I am trying to use the ArcGIS "Raster to Other Format" Conversion tool from a .bil file to a TIFF image. I have the following Python code to create the .bil file shown in this ArcGIS tutorial: ...
2
votes
0answers
202 views

Publishing ArcGIS geoprocessing service - upload custom python modules? [closed]

I have an ArcGIS geoprocessing service which causes problems when publishing to arcgis server. The python scripts behind the service are structured as a custom python module, in a folder with an ...
3
votes
1answer
234 views

How to clip a Oracle query layer directly in a Python script?

I have a query layer directly running from ORACLE database in a MXD. I want to clip this layer with a layer being created in another MXD in a Python based tool. My question is to do this clip ...
1
vote
1answer
205 views

Using GDAL to read dted files

How do I get the elevation at a certain point using gdal to read in a dted file? I don't see much useful information out on the web. I'm sorry I should have been more specific. How would I ...
2
votes
2answers
273 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 ...
0
votes
0answers
59 views

Python - Taking list of cities out of .txt file and printing them to another text file with coordinates from Google [closed]

new here, and this is my first post. I have a python script that I am working on, and the scripts main purpose is to take a list of cities from a .txt file on my computer, and have the script spit ...
2
votes
2answers
54 views

How do I serve OSM map tiles (mbtiles) from a Raspberry PI 2?

My main processing machine is a Ubuntu box running 14.04 with PostGIS and TileMill. I generated my tiles and the resulting mbtiles export is about 250MB (megs, not gigs). The PI runs python, has a ...
1
vote
1answer
40 views

How do I properly import python sklearn to QGIS PyQt plugin?

A bit of background: I'm somewhat new to python and QGIS plugin development. I've created a plugin structure for QGIS using the Plugin Builder on QGIS and I've added some controls to the gui and ...
2
votes
1answer
47 views

Layer properties dialog in my QGIS plugin

I am developing a plugin which should display some information like geometry of the layer, feature count etc. Now those are currently displayed in QMessageBox.information. I want it to be displayed ...
2
votes
1answer
104 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 ...
2
votes
0answers
21 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
34 views

Issues with PyQGIS while running a QgsZonalStatistics script

I have experienced a very bizarre issue with my PyQgis code. I simply want to load a raster and a vector layer to do zonal statistics, the first part works perfectly but for the zonal statistic I have ...
0
votes
1answer
42 views

How to trigger a QGIS action when a plugin button is clicked?

I tried calling the select free hand tool by below snippet of code. iface.actionSelectFreehand().trigger() I dnt have any idea how to call this when i am pressing a button in GUI. my gui is ...
2
votes
1answer
115 views

Accessing CRS info with pyqgis in a standalone application

I'm currently having trouble accessing and defining CRS information in a standalone application. I've read the API documentation and have tried it in the python console in QGIS 2.2.0. The python ...
0
votes
0answers
21 views

Why does np.multiply change int nparray to float? [closed]

I'm working on a Debian system using Anaconda/Spyder. I'm multiplying large ndarrays such as the following: out = np.multiply(array, .0001) where: array.dtype = int16 but the final output array ...
0
votes
2answers
71 views

How to add XY point and update attributes with ArcPy 10.0

I would like to create a script tool that takes 3 parameters in ArcMap: Google maps coordinate (e.g. -33.876846, 151.215117) text string text string The coordinates would define the XY geometry, ...
1
vote
1answer
57 views

Is there a Python implementation of a Straight Skeleton algorithm?

I'm looking for a Python package which provides an implementation of a Straight Skeleton algorithm. I'm aware that the open source (C++) project CGALcontains an implementation but it seems like ...
-4
votes
0answers
47 views

How to find a point inside a multipolygon?

I have a table postGIS with a column (type: geometry(Multipolygon)). One of the entries looks like below. How do I convert them into polygons ? or If I have a geo-coordinate , is there a way to find ...
1
vote
1answer
36 views

Difference between osgeo gdal/ogr python module and GDAL C++ library

I am developing application in python and I use the osgeo gdal/ogr python bindings for gdal, but its not clear to me what exactly is the difference between the gdal/ogr in python and the gdal library ...
0
votes
1answer
25 views

How to connect mouseclick to map canvas in QGIS?

How to connect mouse click to map canvas in QGIS using python script? I have two lines of code to connect mouse click to map canvas: button.clicked.connect(self.onClicked) ...
-1
votes
0answers
45 views

Creating shapefile from georeferenced image?

I have a jpg image and a list of ground control points, I am looking to programmatically create an associated shapefile in python.
3
votes
1answer
816 views

Pass a variable from Modelbuilder into a Python script

I'm new to modelbuilder and python. I have used modelbuilder to iterate through all rows in a shapefile (Points), process them, and produce a seperate output shapefile for each row. The filename is ...
2
votes
1answer
47 views

Error with Python Script using Shapely

My professor gave us a basic Python script that demonstrated how Shapely works with a shapefile, however it's not working for me. Here is the code: from shapely.geometry import mapping, shape from ...
2
votes
2answers
124 views

Delete Files in a folder and disregard an existing folder

I did a lot of geoprocessing steps and now I like to delete all files including result, result, _join, _interand reclass in their name. I can do this with the following import glob import os for fl ...
2
votes
1answer
74 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 ...
11
votes
7answers
1k views

How to implement value-by-alpha map in GIS?

I've been doing some background reading about cartograms recently and stumbled upon interesting alternative - value-by-alpha maps. Concept is described in more details here and full paper is ...
4
votes
2answers
538 views

Efficient computation of nearest distance for each point to closest polygon

I'm looking for a more efficient way to compute the nearest distance between features from 2 layers, in this example for each point the nearest distance to the closest polygon. Is there a more ...
1
vote
1answer
42 views

How to call default tool in QGIS inside plugin using python script?

I want to create a plugin which can draw irregular polygons in QGIS. For that, I want to call the Select features by freehand default tool inside my plugin. How can I do this within a python script?
1
vote
2answers
115 views

Using Python in the field calculator - if/else over multiple fields

I'm trying to work out how to populate a field depending on the lowest score across 6 other fields. I've read several other questions relating to if/else statements but I'm only just starting to learn ...
10
votes
2answers
655 views

How to implement MultiValue Parameter with Multiple Columns?

This might be a simple question, but I haven't been able to find a straightforward answer. I'm working on an ArcGIS (9.3) Python script. One of the inputs is a list of features. For each feature, I ...
7
votes
3answers
4k views

Setting parameters in Script Tool using Python?

I hate to bug you all with the same problem over and over again but I run into a new problem everytime I make a slight change to the code. All I did to the code below was to replace field names to ...
1
vote
1answer
1k views

SImple model works, resulting script doesn't

The goal is to convert an XY layer (from Excel) into a feature class. The "MakeXY" portion works flawlessly, the arcpy.FeatureClassToFeatureClass_conversion portion inevitably returns a 999999 "Table ...
5
votes
1answer
2k views

How to Make a New Shapefile Based on Attributes of an Existing Shapefile?

In my last post I had an issue where I wanted to create multiple shapefiles based on only one attribute field (years). How to do it was answered in that post. I want to make that tool more dynamic so ...
0
votes
0answers
27 views

web2py - openlayers

I have used web2py and there is test.py under controllers which shows a map as below: and its code is: for url in [ 'http://dev.openlayers.org/theme/default/style.css', ...
0
votes
0answers
18 views

Reading long lat values from line feature

I have created a vector layer selecting starting point and end point of the line and created the line by line geometry in QGIS. How do i read the all long. lat. values in the line feature? v_layer = ...
1
vote
1answer
185 views

Flatten / collapse one-to-many table and keep the 'many' attributes separate

I have a data set that contains intersection data. Each intersection node has up to 6 links which is identified by IN_LINK and OUT_LINK attributes. I want to create a new dataset that includes the ...
2
votes
1answer
1k views

How to fix python ImportError: DLL load failed: The specified module could not be found?

During import fiona, I am getting following error. Error is different from other user so I asked this question may be it is repeated. import fiona Traceback (most recent call last): File ...
1
vote
2answers
70 views

Debugging 'module' object has no attribute 'SdeWorkspaceFactory'?

I am new to python, am debugging one of existing python code, where am facing an error "'module' object has no attribute 'SdeWorkspaceFactory". Earlier this code was working fine but suddenly does not ...
1
vote
1answer
25 views

QGIS (2.6.1) Processing Toolbox InitGui error after changing /Users folder on Mac OSX

Using: Mac OSX 10.9.4 QGIS 2.6.1 I had previously installed QGIS and had everything running fine. My home directory was /Users/rowanbado, but for another application I had to add an ...