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

learn more… | top users | synonyms

1
vote
2answers
137 views

How to plot Storm Prediction Center (SPC) Shapefile using python

I am trying to make a plot of the SPC's thunderstorm outlook using Python. I have downloaded the shapefile from this website http://www.spc.noaa.gov/products/outlook/day1otlk.html. Then I use this ...
1
vote
3answers
49 views

SearchCursor Index Out of Range

I'm using ArcGIS 10.2 and trying to obtain values in a field using SearchCursor. Would someone help me with this? import arcpy oc = r"C:\Users\Scratch\oc.shp" catchments = ...
1
vote
1answer
62 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 ...
3
votes
2answers
47 views

How to define layer's CRS and avoid the CRS dialog in PyQGIS?

There is an existing Shapefile, which I want to add. At the moment my code looks like: self.iface.addVectorLayer(self.shpFilePath, "Track", "ogr") It works fine, but i want to define the crs ...
1
vote
1answer
45 views

How to add multiple attributes to a newly created feature with PyQGIS

I am creating a form for updating the attribute values of the newly created feature. But when i am updating the values only one attribute field is getting updated. So if i want to update the multiple ...
3
votes
2answers
154 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
62 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
37 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
91 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
10 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
535 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
37 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
60 views

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

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
42 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
63 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
63 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
209 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
213 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
281 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 ...
3
votes
2answers
72 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
43 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
51 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
105 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
22 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
42 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
45 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
121 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
2answers
78 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, ...
-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
39 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
28 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
46 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
824 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
49 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
126 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
80 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
545 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
49 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
127 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
664 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
33 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
19 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
190 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 ...