2
votes
1answer
26 views

QGIS way to import OSM/Google Maps but remove or exclude extraneous areas, limit geographically the use of OSM

GIS Newbie question, perhaps: But I am looking to place an Open Street Maps/Google Maps layer underneath the rest of my shapefiles for referencing purposes. Let's say for instance, that I am looking ...
1
vote
1answer
68 views

Why is feature.geometry() None in my user-defined expression function?

I'm trying the user-defined expression functions for QGIS, as listed on Nathans blog: http://nathanw.net/2012/11/10/user-defined-expression-functions-for-qgis/ I always get the feature.geometry() as ...
1
vote
0answers
36 views

Scaling features based on an attribute

I would like to scale polygon features by a specific factor I have calculated for each feature in a feature class. I know of the Scale tool, however it only allows for manual entry of a scale factor ...
0
votes
0answers
14 views

QGIS plugins - how to use a custom behaviour on right click and actionPan on left click?

I have been struggling with this problem for quite a long time. Here we go : I implemented a maptool that draws a red cross on the point that is being right-clicked on. There are good how-tos, such ...
4
votes
1answer
69 views

How do you set the position of a plugin window when you start the plugin?

I'd like to set the position of a plugin's window or dialog relative to the map canvas frame. For example, if I start a plugin, I want it to appear somewhere in the left upper corner of the map ...
0
votes
1answer
38 views

How to add new columns with attributes in existing Qgis layer?

How to add new columns with attributes in existing Qgis layer? Doing the "same thing" here described
4
votes
1answer
33 views

Can QGIS map canvas update while python script is running?

I want to automate a periodic refresh of the QGIS map canvas with updated shapefiles. A Python plugin or console script does not allow the map to update until the script terminates. Is there a way to ...
2
votes
1answer
58 views

Python console not working at all

My python console won't work at all. I can't open it. My QGIS version is 2.4. OS is win7 64. I've reinstalled QGIS a few times but I always get the same result. Strange. Something went wrong with the ...
1
vote
1answer
44 views

Programmatically export a Qgis project

I have a QGis project that I programmatically modify using the Python xml.etree library. Now, I would like to know if it is possible to add few lines to my script in order to export the modified ...
4
votes
1answer
102 views

Can ArcGIS ModelBuilder be exported to Python and run in QGIS?

Is it possible to construct a geoalgorithm on the ArcMap modelbuilder, export this entire algorithm to python syntax (without having ANY knowledge of python) and then import this algorithm to QGIS and ...
3
votes
1answer
58 views

No get more option in QGIS

I have recently installed QGIS and trying to work with it but I don't see this option "Get More" at all. As suggested by some previous source, I also checked whether I am behind a proxy but that isn't ...
1
vote
0answers
22 views

pyQGIS 2.0: Sending signal when identify button is pressed via gui

I have a question regarding the qgis identify tool for version 2.0. I would like to know if it's possible to send a signal when the actionIdentify is triggered by the user via the gui. I'm trying to ...
2
votes
0answers
48 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 ...
4
votes
0answers
51 views

Preparing Huff model with data to use in QGIS? [closed]

I'm trying to find out about the notion of potential of acessibility using the methods of Huff. I´m using QGIS, with point data (with the variables that I would like to use) and polygons for Europe ...
2
votes
1answer
36 views

Conditional Statements in QGIS raster calculator?

What is the equivalent statement of the following expression in the QGIS raster calculator? Con(((Abs("DEM" - "FSMin") > 120) | (Abs("DEM" - "FSMax") > 120)), 1, 0) I have no problem ...
2
votes
0answers
23 views

Memory layer or QgsVectorFileWriter Error?

Currently this excerpt of code will not save to file (as it is supposed to). The memory layer is visable and editable. Yet even when manually saving the layer, any priorly added features ...
1
vote
0answers
9 views

Proper updating of new memory layer geometry?

Current workflow for a toolbar button: -create memory layer -save memory layer to shapefile Then the user uses the built-in QGIS tools to add geometry and finally saves changes via the auto prompt ...
6
votes
2answers
243 views

Versions of Python & QGIS for new user to both to install?

I have used GIS (very basic functions), but now want to be able to customize to my needs. My initial research leads me to believe that Python + QGIS is the way to go. I understand that there are ...
1
vote
0answers
15 views

QGIS2.4.0: Cannot import qgis module in python “from qgis._core import * \n DLL Load Error”

Having some trouble importing qgis into python. I'm very new to python so it could be a simple mistake. The path seems to be correct. It gets this far: File "<stdin>", line 1, in ...
1
vote
0answers
29 views

Vector layers without geometry in QGIS?

Using QGIS, I have set up a couple of automated layer additions via the toolbar. After adding geometry in each respective layer (point, lineString, polygon) and saving changes to the layers, the added ...
2
votes
0answers
21 views

Align & Sum Grids in Python

I have two grids. One, call it A, is 4320x2160 cells and spans the whole globe. The other, call it B is 8640x3432 and spans the circumference of the globe, but is clipped toward mid-latitudes. Both ...
1
vote
1answer
21 views

PyQgis Message Bar Woes [closed]

Having a bit of trouble with the basics of getting the (awesomely discreet) new user prompt/warning to properly display. Here is the (troubled) code I am using: self.iface ... ...
1
vote
0answers
13 views

Vector Layer Symbol (ism) properties?

I would like to streamline the render of a polygon grid vector layer as a simple line (no fill) via Python coding. I am I bit confused by the implementation referenced by the API. Is it possible to ...
4
votes
1answer
107 views

QGIS 2.2 - possible to do a JOINS from the Action list?

I have a set of layers that need to be joined (Layer Properties > Joins) to one specific layer. The reason for this is that I will be updating and adding new layers into my project and would like a ...
1
vote
0answers
24 views

How to make crs transformation of a QgsVectorLayer?

I need to transform QgsVectorLayers in python from one crs into another crs. By googling I found the following solution ...
1
vote
0answers
33 views

How to programmatically interrupt QGIS initialization and startup

I'm wondering how to interrupt the initialization of QGIS 2.0 on Windows XP before start up. I've put a dialog in one of my plugins that shows up on start up. However, I'd like to make a quit button ...
2
votes
0answers
44 views

Saving/Loading QGIS style .qml and avoid specified symbology

Is it possible to save QGIS styles without the symbology style? This may seem like a strange question, but I am trying to automatically set the ValueMap widget under layer properties via a plugin for ...
0
votes
1answer
47 views

How to delete column/field in PyQGIS?

How to remove or delete column fields in a shape file using python?
1
vote
1answer
48 views

How to write a (memory) layer from QGIS to PostGIS?

I am looking for an "elegant" solution to write, from a python script, a layer from qgis and into a new table of a PostGIS database. I thougth that this might be solved by QgsWriteVectorLayer, but I ...
0
votes
0answers
33 views

Is there a way to take control of the mouse pointer using python in QGIS?

i would like to take control of the mouse pointer in QGIS (for example constraining it to a given extent...) Is there any way to do that using PyQGIS ? Thanks !
1
vote
0answers
27 views

How to sort a column in attribute table programmatically

Is there any way to sort ( alphabetically ) a column in the attribute table programmatically (without clicking on the column header) in QGIS ?
2
votes
1answer
58 views

data source for worldwide cross-sections of topographic and bathymetric for woodworking art project?

i am a decent r programmer and statistician, i am able to work with data sets pretty well. i am less familiar with GIS tools, but if given a shapefile i can certainly plot political borders and ...
1
vote
1answer
34 views

Couldn't load SIP module (QGIS doesn't load Python)

I recently installed QGIS 2.4, but Python does not load. I am running on a Windows 64 bit machine. I receive the error message "Couldn't load SIP module Python support will be disabled". Traceback ...
0
votes
0answers
38 views

Is it possible to rotate the geographic projection in QGIS?

I'm trying to create a Qgis plugin that can rotate a raster layer in the canvas so that the north is pointing at another direction. Unlike the thread below, I'm open to defining a custom projection. ...
1
vote
1answer
57 views

What is the inverse of QgsGeometry.asGeometryCollection() in qgis python?

What is the inverse operation of QgsGeometry.asGeometryCollection() as documented here: http://qgis.org/api/classQgsGeometry.html#a7cb1cbf8cfa441456067a66ad3a25a94 I'd like to do something like: ...
1
vote
0answers
38 views

PyQGIS: Editable Combobox for Value Map widget isses

I am having issues with an editable combo box in QGIS 2.4. The edit widget is set to Value Map with an uploaded CSV. However, if a new values (not included in the key value pair list) is added, the ...
1
vote
1answer
108 views

How does one modify selected geometry with a function in qgis python console?

My example use-case is that I want to redistribute vertices along lines as in: Redistribute linestring vertices to specified distance How to create points in a specified distance along the line in ...
2
votes
1answer
45 views

How to do loops on raster cells with python console in QGIS?

I'm new here and beginner with python. I'm looking for a solution to my problem for some hours but now you are my last chance... I'm using the python (2.7.5) console in QGIS (2.4.0). Is there a ...
0
votes
2answers
62 views

Error while importing CSV File using PyQGIS

Currently I am trying to import a CSV file using the python extension in QGIS and I have run into a problem that I can not seem to solve. I am trying to do a basic import of a CSV file from a python ...
0
votes
0answers
16 views

How to get sql error from postgis when a plugin fail to load vector layer?

I am writing a plugin for qgis that load a sql layer from postgis database. I am disappointed that when the layer fails to load i can't find a way to get the sql error message from database server. ...
1
vote
0answers
27 views

Import QGIS Python modules in Python command line or standalone script

I am running a Windows 7 machine with Python version 2.7.8 (32 bit). I installed QGIS 2.4 (Chugiak) from OSGeo4W and simply want to be able to import the QGIS Python modules (e.g. qgis.core) into ...
1
vote
0answers
29 views

Link to pdf file through mouse clicking

I need help in identifying the feature attributes displaying a pdf file when click in that feature. I see many examples but I don't have success. I try this code: command = "firefox"; imagerelpath = ...
2
votes
1answer
31 views

Python Error while installing Cartogram

I am quite new to GIS and qGIS especially. I would like to install cfarmers cartogram plugin. From what I understand, this has to be done manually - so I 've followed the instructions from ...
1
vote
0answers
26 views

How to write a custom map canvas item by subclassing QObject and QgsMapCanvasItem?

I'm writing a QGIS python plugin where I place some QgsVertexMarkers on the canvas like this: marker = QgsVertexMarker(self.canvas) marker.setCenter(QgsPoint(point[0],point[1])) Now i would like ...
0
votes
0answers
28 views

How to select duplicate polygons? [duplicate]

Although it may seem this has been answered before, there doesn't seem to be a solution. I am trying to simply select duplicate polygons. I don't want to delete them or anything like that. I need ...
0
votes
0answers
25 views

Exporting ArcSDE feature class to shapefile using OGR?

I'd like to export data from ArcSDE for SQL Server to SHP. I've tried first to run this python script in QGIS: http://trac.osgeo.org/gdal/browser/trunk/autotest/ogr/ogr_sde.py But finally I've got ...
0
votes
0answers
24 views

QGIS 2.4: adding feature with setLineEdit() data not saving to database

A while ago, I struggled to get a combo box working correctly for QGIS 2.0. This involved transforming a combo box into a line edit if the item named "other" was chosen, enabling the user to add a ...
0
votes
0answers
14 views

Python error with OpenLayers [duplicate]

I have recently downloaded QGIS 2.2.0. I am trying to use OperLayers, but I constantly get this message: Errore durante l'esecuzione di codice Python: Traceback (most recent call last): File ...
0
votes
2answers
155 views

QGIS 2.4: plugin changes map tool canvas click behavior from 2.0

I had created a plugin for QGIS 2.0 to add new features more easily. It involves changing extents and updating snapping options along with triggering the default actionAddFeature(). However, I've ...
2
votes
1answer
185 views

Python support with QGIS 2.4 on Ubuntu 14.04

I recently updated my Ubuntu system to version 14.04. I added the sources and installed QGIS as per the directions on the QGIS website. Everything looks good, except for I do not have all the ...