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

learn more… | top users | synonyms

0
votes
1answer
201 views

gdal polygonize in python error, blank polygon created

I am having trouble using the Polygonize function in python. The cookbook example for this can be found here. The relevant portion of my code is: sourceRaster = gdal.Open('myraster.tif') band = ...
0
votes
0answers
102 views

How to convert .shp file to zip file with mapnik?

I am creating android application for campus indoor map. I research so much think.I decide use osmdroid. I write here what I have done 1) I draw indoor map with JOSM. 2) I convert file.osm file to ...
0
votes
0answers
33 views

Does a road connect one grid cell to an adjacent grid cell?

So here is the problem I am working on. I have an OpenStreetMap roadmap which I overlaid with a 2-D cartesian grid. So for a given grid square, I want to find out if a road segment continues from the ...
0
votes
0answers
26 views

How to intersect widget using script python arcpy and geoprocessing service? [closed]

Is it possible to develop an intersection widget with geoprocessing service using script python arcpy? I try to do that with ModelBuilder but after publishing, in geoprocessing service i don't find ...
0
votes
0answers
44 views

Check if Openlayer Layer is empty, caused by nonexistence of internet connection?

I use Openlayer Google street map as a base-map in my QGIS plugin projects. i want to check programatically if the layer is loaded or is empty and decide if i load my offline base-map instead of ...
0
votes
0answers
61 views

Using iface.showAttributeTable() on QgsVectorLayer retrieved by getObject()

I'm unsure if i'm properly using the processing.getObject() function. I'm creating a python processing script for QGIS 2.0 and 2.2, but can't seem to get an attribute table to open programmatically. ...
0
votes
0answers
141 views

Issue blocking QGIS feature form dialog with Python

I'm not sure where I'm going wrong with this python logic for a custom form in QGIS 2.0.1. There are a few things required by the validation function: that index of combo boxes aren't 0 (first index ...
0
votes
0answers
41 views

QGIS Plugin: Show a symbol at coordinates

I want to code a plugin for QGIS showing a specifig image (e.g. a .png or .ico file in the file system) at given coordinates. The background is, that I'm receiving coordinates and other information ...
0
votes
0answers
35 views

RemapValue Usage

I successfully produce and empty cost raster at the end of this script. I am fairly confident it has something to do with RemapValue parameters? Does anyone know why my out put cost distance raster ...
0
votes
0answers
24 views

slope in model different value than slope in stand alone script [duplicate]

When running slope(analysis) from model I receive a high value of somewhere around 71. After then exporting model as python snippet and changing only the output raster name (using same input raster) I ...
0
votes
0answers
50 views

Programmatically add paramaters to ArcToolbox based on number of FCs in GDB?

I'm creating a custom geoprocessing tool. If a user inputs a GDB with a variable number of feature classes (FC), how can I retrieve and add a list of the FC to the tool? If the user doesn't add a ...
0
votes
0answers
65 views

Data driven page error when adding world_file

my python script for data driven pages causes a runtime error when I set world_file=True, or geoTIFF_tags=True. Else it runs and shots the ddp - in this case a grid of my city. I'm searching the web ...
0
votes
0answers
34 views

How to make turn feature class from line feature class?

I have a road network of one county in Norway . To this road network, I will make myself a turn feature class of all the road barrier in the road network. I have a feature class with all the road ...
0
votes
1answer
70 views

replace data source for all layers that point to shapefile

Hi I'm trying to do something quite simple but its not working. I want my python script to change all of the layers that point to the same datasource (a point shapefile) to another point shapefile. ...
0
votes
1answer
46 views

Retrieve path of running plugin in QGIS

In my plugin's directory I've got some XML settings files that I'd like to parse at a particular point during execution of the plugin. Is there a way to get the absolute path where the plugin's .pyc ...
0
votes
0answers
155 views

How to read out the geoPDF data downloaded from USGS ned database?

I am new to GIS, so this might be a stupid question. Google foo din't get me anywhere, so here goes.. How do I read the geoPDF data that I download from the National elevation database from USGS? ...
0
votes
1answer
21 views

whereClause syntax for Cost Distance parameter

I am looking to create a sql expression regarding point feature class and selection based on 'Name' field to pass to arcpy.sa.CostDistance() param[0]. similat to: savepath = env.workspace = ...
0
votes
0answers
34 views

How to select Qgis features through Python Plugin

Hi I am very new to Python so this may be a bit basic. I am trying to find a way to select and zoom to the features in a QGIS layer. I have created a plug in and built a custom form. I have 3 ...
0
votes
1answer
78 views

Weighted Overlay - passing parameter as text error?

For some reason when hardcoding the save path for the wieghted raster just before runtime it works perfectly. Like such... arcpy.env.cellSize = "90" arcpy.env.workspace = r'G:\Xcel\Route ...
0
votes
1answer
36 views

Changing band for greyscale in plugin

I am trying to make a qgis plugin to change which band in a multiband data set (netCDF where the band represents time steps) is used for a grey scale rendering. The file works fine with manual ...
0
votes
1answer
267 views

How to generate jVectorMap for United Kingdom (UK)?

I have shapefile for UK , i need to convert this to the jVectorMap Here is my script python ^ converter.py ^ ./shapefile/map.shp ^ ./output/jquery-uk.js ^ --width 400 ^ --where "ISO = ...
0
votes
0answers
96 views

No data appears when using gdal_calc.py but source had data values

I'm in the process of calculating topographic exposure using a mix of GDAL, grass, R and python in Windows. I need to process a very large tiff file using the following calculation: ...
0
votes
0answers
93 views

TileStache : Unknown geometry type in geoJSON file

I'm currently trying to set up a TilSstache server on Ubuntu 12.04 to serve some GeoJSON tiles from a shapefile/JSON file (administratives boundaries) for a web mapping project using the Leaflet ...
0
votes
0answers
127 views

UnicodeEncodeError when using arcpy.gp.TraceGeometricNetwork_management() [closed]

I am creating a python tool (run through ArcMap) which will eventually go through a feature class selected by a downstream trace and use the obtained values to do some function. I am trying to follow ...
0
votes
1answer
66 views

How to disable “Simplify geometry” via Python?

After I've loaded a layer from a table in my db I'd like to disable the 'Simplify geometry' (found in Layers/Properties/Rendering) programatically using Python. I've tried several versions of ...
0
votes
0answers
26 views

Add a raster specifying the projection in pyqgis

I would like add an raster but I want to specify the projection. If I do : qgis.utils.iface.addRasterLayer(url,layerName) QGIS ask me to specify the projection. I want to this with python. How I ...
0
votes
0answers
37 views

Delayed moving average

I want to develop a plot of delayed moving average. The code for this in MATLAB is: nr_pontos = 36; coefs_filtro = ones(1, nr_pontos)/nr_pontos; data_dma = filter(coefs_filtro, 1, data); ...
0
votes
0answers
194 views

Mac QGIS 2.2 error executing Python code

Newbie Using QGIS version 2.2 with Python 2.7.5 on OSx 10.9.2 Getting the following error. Any idea on how to resolve? I'm not sure if it has ramifications on the display of the Google data. An ...
0
votes
0answers
48 views

Convert raster_stats list output to array / csv file

I usually program in R, but recently I have started to use python for most of my spatial programming. My python skills are still limited, and please excuse the simplicity of the question. I am ...
0
votes
0answers
24 views

Points Missing on Import of LongLat data to SHP using ESRI script CreateFeaturesFromTextFile()

In ArcMap 10.0 I am using a 9.1-era ESRI script in Python called CreateFeaturesFromTextFile. There appears to be no ArcMap 10 update. The input text format is the strict format ESRI point,X,Y layout ...
0
votes
0answers
82 views

I could use some help with a bit of code optimization

See edit below. I posted here a couple weeks ago looking for some advice on the best way to iterate through data. You can find that post here. I have since done some tweaking to the code, and ...
0
votes
0answers
81 views

using postgis function in pyqgis

I'd use Postgis function in Pyqgis script. This code: qsql="(select gid, id, St_Buffer(the_geom,200) as geom from archi)" uri = QgsDataSourceURI() uri.setConnection("ip", "port", "x", "x", "x") ...
0
votes
1answer
195 views

visualize bounding box to a polygon

I try to make plugin in QGIS that compare 2 bounding box data, ex: (-32.61442167739459, -32.017601026186576, 13.015663782506067, 13.428145228091406) and (-38.6102467739459, -38.017601026186576, ...
0
votes
1answer
165 views

Polygon Neighbors Analysis script (ArcPy 10.1) producing erroneous results?

I'm struggling with a python script that is supposed to calculate a field for a polygon feature class. The calculation is of the average of a field value (P_TOT_DEV) for each of a given polygon's ...
0
votes
0answers
187 views

Using ArcPy, is there a way to change the color of a symbol in a UniqueValuesSymbology object?

I have an template mxd I reference with several pre-defined layers. The only variable I need to modify is the color of certain symbols in the layer. I have tried to modify and dig around the Symbology ...
0
votes
0answers
94 views

Nearest road in the vicinity of a point without queries (openstreetmap)

I know that many similar questions about map fitting have been asked. Everywhere there were answers about sql queries like this: SELECT ST_AsText (ST_ClosestPoint (pt, line)) AS cp_pt_line, ...
0
votes
0answers
75 views

QGIS Plugin to open metadata and show metadata information

I try make plugin to open and read metadata (.xml) and show information inside metadata like map scale, map fiture and bounding box and auto fill it to QLineEdit This code i use to open metadata ...
0
votes
0answers
72 views

Getting “Segmentation fault: 11” with ogr in Python

This is the code I'm trying to run: In [1]: from osgeo import ogr In [2]: datasource = ogr.Open('testdata.shp') In [3]: datasource.GetLayerCount() Out[3]: 1 In [4]: layer = ...
0
votes
0answers
41 views

Suggestions on how to create an Owner Index for a Plat Book?

I've been tasked with creating a county wide plat book for publication this june. The cartography portion is fairly straightforward as I am using ESRI's Data Driven pages for ArcInfo 10 to produce the ...
0
votes
0answers
88 views

Algorithm to find coordinates at selected intervals along a polyline?

I am developing an algorithm to search down a river at selected intervals and return the coordinates. See below: def Downstream(start, interval, data, offset=0, out=None): if out is None: ...
0
votes
1answer
157 views

PyQt4 pushbutton not connecting for my QGIS plugin

I'm trying to display information in a text browser with the push of a button in my QGIS plugin. The .ui is created using PyQt4 (button's object name is calcConso). No error message, but the button ...
0
votes
0answers
18 views

std::bad alloc when writing simple script in QGIS

I'm running QGIS 1.8 on Scientific Linux and I'm attempting to write a script (obviously this will be built upon to do something useful) which simply writes to a file. ##raster=raster value=5 ...
0
votes
0answers
47 views

How to get the signal when the color changes in pyQGIS?

I would like to have the signal when the color of a vector layer is changed by the user. In the doc, there is a signal that seems to fit ...
0
votes
0answers
67 views

Creation of drainage ditch in ArcGIS - Line with a certain slope

I have a digital terrain model and a list of problematic points, in which water accumulates. It's not important how I obtained these points (by observing or some algorythm). I would like to use these ...
0
votes
0answers
87 views

GEOS assertion failed

The following script fails, if I import the 'rasterstats' library. import rasterstats import ogr geom1 = ogr.CreateGeometryFromWkt('POLYGON ((415924.806155724043492 ...
0
votes
0answers
78 views

Creating a line along an existing polyline from a point

I have a large data set of points, all of which lie on a river network and have x, y co-ordinates. I want to calculate the slope of the river channel at each point from the underlying DEM by taking ...
0
votes
0answers
43 views

How to add field to postgres layer with PyQgis?

I'm fetching a posgtres layer with PyQgis and then I'm trying to add field with this: lyr.startEditing() lyr.addAttribute(QgsField("class", QVariant.Int)) But It is not adding the field and also ...
0
votes
0answers
83 views

arcpy.SearchCursor strangely throwing IO Error

I've been trying to use arcpy.SearchCursor on an xls file. Something I've done countless times before. I had a script running and then yesterday it started throwing: IOError: ...
0
votes
0answers
146 views

ArcGIS Python Field Calculation

Ok so i've got a problem with the field calculator in ArcGIS: I'm already pretty far with it since i got some help :P but it still doesnt work. What i've got: -A complete table of several states of ...
0
votes
0answers
78 views

Spatialite not available from qgis python console

I have a problem using pyspatialite from within the qgis python console. When I run the following code in ipython from pyspatialite import dbapi2 as sqlite conn=sqlite.connect("MyDB.sqlite") ...