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

learn more… | top users | synonyms

3
votes
1answer
965 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
votes
2answers
977 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
votes
1answer
58 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 ...
1
vote
1answer
64 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
votes
1answer
9k 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 ...
0
votes
0answers
24 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 ...
0
votes
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 ...
1
vote
1answer
523 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
votes
1answer
564 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 =...
0
votes
0answers
63 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
votes
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 ...
1
vote
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
vote
2answers
105 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 ...
0
votes
1answer
255 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 ...
7
votes
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, ...
1
vote
0answers
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 ...
1
vote
1answer
53 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,...
5
votes
1answer
111 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() ...
5
votes
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 ...
1
vote
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 ...
3
votes
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
votes
1answer
271 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 ...
0
votes
1answer
49 views

Write GeoJSON As Feature Object in Postgis

I'm trying to create a geofence/circle from a lat/long set and I'm close except that the GeoJSON that PostGIS creates differs in structure from the client library that our front-end uses. Here is my ...
1
vote
2answers
307 views

how to find that two polygon boundaries are connected?

I am working on a Geo database where there is a layer with many polygons. i want to find that which polygons boundaries are connected so that i can create new layer from that polygons and which ...
2
votes
1answer
18 views

SyntaxError with custom function using QgsFeatureRequest.setFilterExpression

def get_subsel(layer,filter): layers = iface.mapCanvas().layers() for lyr in layers: if lyr.name() == layer: request = QgsFeatureRequest().setFilterExpression(filter) ...
0
votes
1answer
84 views

Clipping GeoTIFF file by GeoJSON?

Input GeoJSON file: { "type": "Feature", "properties": { "id": 1 }, "geometry": { "type": "Multipolygon", "coordinates": [[[ [27.397511483867362, 44.161117466010516], [...
1
vote
1answer
70 views

Install GDAL python package in virtualenv on mac

I'm trying to instal the GDAL python package, preferably in a virtual environment, but when I try "pip install gdal", I get the following error: extensions/gdal_wrap.cpp:3085:10: fatal error: '...
2
votes
1answer
41 views

Creating an Interrupted Map With OGR, Mapnik and PIL

I am trying to create a simple interrupted Sinusoidal map with Python using OGR, Mapnik and PIL. The general idea is: Make 6x 60 degree sinusoidal maps For each one, make a mask to make it gore ...
1
vote
0answers
31 views

How to change which python GDAL is “connected” to?

I would like to use GDAL with Python 2.7 on Ubuntu 14.04. I have installed gdal-bin and python-gdal from UbuntuGIS following their instructions. However, importing GDAL (from osgeo import gdal) only ...
4
votes
4answers
6k views

How can I fix “ImportError: No module named qgis.core”?

First of all, I'm using Python 2.7.3, QGIS 1.8 (Lisboa) on Windows 7 pro 64 bits. Now let's go to the actual question: I have written some code (Python) that works well within the QGIS built in ...
0
votes
1answer
18 views

Parsing error with field calculator [closed]

I am trying to do a simple calculation that populates a field based on a set of acreage figures. I am using if/else if statements with acreage ranges. Here is the python script I came up with. def ...
3
votes
1answer
106 views

How to use Qt3 Support widgets in QGIS plugin?

Similar to this post: My plugins crashes with “No module named qgsprojectionselectionwidget” in Windows. Except I would like to also use Qt3 Support widgets (in particular, a Q3ButtonGroup). However, ...
1
vote
0answers
25 views

batch convert geojson to shapefile [duplicate]

I have a directory full of geojson files that I need to convert to shapefiles for editing in QGIS. As far as I have searched, there are no resources in GIS StackExchange that explain how to do this ...
1
vote
0answers
24 views

Segmentation fault in readasarray

I am running the following code and get: Segmentation fault (core dumped) I have no clue why, I have been using the functions many times before and now suddenly this happens. Sometimes it happens at ...
1
vote
2answers
47 views

Values extracted from NetCDF not matching original raw data

I am working with monthly rainfall data from University of Delaware which is available as a NetCDF from NOAA and raw text from UDel's homepage. I would prefer to use the NetCDF format but when I ...
1
vote
1answer
40 views

Array written by GDAL with Python script has numbers read as “nan” by QGIS?

I would like to write an array to a geotiff with Python script using the GDAL module. When I try to do something simple like copying an existing GeoTiff via reading it to an array, then, writing to a ...
1
vote
1answer
608 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 ...
2
votes
1answer
272 views

gdal_calc works but I get a Python error at the end of each process

I have a problem while using gdal_calc by a .bat file. Here is the code : call "C:\OSGeo4w64\bin\o4w_env.bat" gdal_calc -A"D:\tuilage_script_1\tuilage\ndvi\4_810000_6370000_820000_6360000_ndvi....
1
vote
1answer
80 views

Dynamically move map canvas and main window using PyQGIS

I am trying to create plugin that will open new window with some layer, Dynamically "pan" my window, when main window is pan. So boundingbox coordinates should be the same in both windows. I need new ...
1
vote
1answer
69 views

gdal/python WriteArray working for 8-bit but not 16-bit

I'm trying to use GDAL/python API to open a raster, do some math, then write the two resulting arrays as rastes. One is to be an 8-bit raster and the other 16-bit signed. However, only the 8-bit ...
1
vote
0answers
15 views

Getting the activeLayer() in Eclipse

I've been working on a plugin in python for qgis. I'm using Eclipse-pydev with remote-debug. I believe I'm set up correctly; I've followedthe Cookbook instructions completely. When starting remote-...
0
votes
0answers
11 views

gdalwarp fails based on output filename? does it have to do with my using -t_srs?

I am so confused by what is going on with my gdal warp. From my terminal I can enter a command for it: $gdalwarp -t_srs '+proj=ortho +datum=WGS84' test_imagery/Maui/OBS_IMAG.nitf testout3.tif ...
3
votes
1answer
75 views

Python to create new fields in many layers / QGIS

I have a number of line layers on which I need to perform the same task: add 4 columns with the start and end points of each line. The expressions that I use to do this are: $xat(0) $xat(-1) $yat(0) ...
3
votes
1answer
125 views

GDAL Python cut geotiff image

I was stuck for 2 or 3 days. I have read many lectures from RS/GIS Laboratory of Utah State University. Also I read «Python Geospatial Development» book and many docs from gdal.org. So, my problem ...
1
vote
3answers
84 views

Writing an if then statement for if a parameter is selected (not Null) in Model Builder

I have a tool I'm trying to create in model builder. I have run into a problem as I have basically no experience with python. I'm trying to basically use the calculate value tool and an if then ...
5
votes
2answers
223 views

Field Editor with Python: select by attribute & open table (QGIS)

I want to search on number values (>, = etc.) within a column and open table for the selected ones. It's an easy task within field calculator, but I want to see how it's build up with the python ...
5
votes
2answers
2k views

how would one get the end points of a polyline?

I am attempting to write a script to get the end points of a series polylines, and then use those end points to create a polygon. I'm not sure which tools to begin to use on this project. I would ...
1
vote
2answers
79 views

python gdal - libgdal.so.1: undefined symbol: sqlite3_column_table_name

I just reinstalled my python environment (and my whole Ubuntu). In python (or IPython), when loading geopandas: import geopandas as gpd or when I import fiona: import fiona I get this error ...
4
votes
1answer
273 views

Adding QGIS-specific Python interpreter to Eclipse?

I was following the steps from QGIS Python Programming CookBook to add qgis interpreter to eclipse, however I went into the following error in step 8: "See error log for details. No output was in the ...