Software plugins that add functionality to the QGIS package
5
votes
2answers
552 views
How to split an irregular polygon into equal areas?
I am a surveyor and use QGIS for maintaining soil test records on civil projects and am constantly provided with test lot area or number of lots required. These are more often than not irregular in ...
1
vote
1answer
96 views
Issues with OSM Plugin in QGIS on Ubuntu 12.04
(not sure how to wrap the subject into a question! But...)
Here are some issues I've been having with the OSM plugin:
1) When I bring in the .OSM file, close QGIS, then reopen, I get a "Handle Bad ...
3
votes
1answer
492 views
Importing shapefile in grass
I have very simple shapefile, which consists of couple of polygons, and I wanted to snap boundaries automatically. Unfortunately qgis doesn't have such function, but grass has according this answer: ...
0
votes
1answer
104 views
FieldPyculator Plugin - How to concatenate fields?
How can i concatenate two fields using pyculator plugin? There is any document with all pyculator functions that i can use in "field expression"?
-1
votes
1answer
40 views
GRASS-QGIS Linking error
I need few customizations over grass and would use qgis gui for accessing grass. I am building qgis with grass enabled (WITH_GRASS=TRUE). While I am doing that I get the following. Any help is greatly ...
1
vote
1answer
132 views
How to hide/show QGisVectorLayer from Python code?
Once created a layer, how can I hide/show it? I can enable/disable rendering of a specific layer by selecting the checkbox through QGIS, but I need to do it programmatically from python code.
How can ...
1
vote
2answers
523 views
How to fix QGIS PyQGIS package?
I have a broken package that is preventing QGIS from loading python plugins, updating itself, or even un-installing.
The main symptom of this problem is the following message that appears when QGIS ...
1
vote
0answers
123 views
How does QGIS execute Python plugins?
I am trying to run a python script from within a python plugin. The script runs a CGIHTTPServer in a separate thread. It works as expected when executed from the command line and i can issue requests ...
2
votes
2answers
179 views
How to create a “Datum-less” projection in QGIS?
I want to use QGIS to do some georeferencing and image registration. On ArcMap10 I can define an "Unknown Projection", basically a default metric grid, and use it as a grid for georeferncing.
In QGIS ...
1
vote
1answer
119 views
QGIS Python error on OS X while trying to simplify shapefile geometries
I am trying to reduce the file size of the shapefile by simplifying geometry in QGiS on OS X.
But I get the following error...
An error has occured while executing Python code:
Traceback (most ...
0
votes
0answers
61 views
How to apply an existing symbol in pyQGIS?
I'd like to change the layer rendering style from python code.
Basically I want to do the same operations I can do from QGis by:
Right-click on a layer
Select Properties
Select one of the displayed ...
2
votes
1answer
142 views
How to remove a vector QgsVectorLayer from QGis python plugin
I managed to add QgsVectorLayer in QGIS through a python plugin, for example:
vl = self.iface.addVectorLayer(uri.uri(), layerName, self.dbConn.getProviderName())
But how can I remove it?
1
vote
1answer
337 views
How can I fix QGIS PostGIS Manager error 'shp2pgsql' is not recognized?
I have QGIS 1.8.0 installed via OSGeo Installer and work on win 7.
All I need is to upload the shapefile to the database via this plugin. Unfortunately I am receiving an error:
Something's wrong:
...
2
votes
1answer
91 views
Road graph tool crashes, but works with sample shapefile [closed]
When I try to calculate the distance between two points using the "Road graph" plugin in QGIS (1.8.0-2, on OSX 10.8.2 ML), QGIS just crashes. It does work with the sample shape file from
...
6
votes
3answers
576 views
How to extract slope from topographic raster map?
I am working on a project for a machine learning class wherein I extract features from a topographic raster map and then classify the traversability of the terrain. One of the features I need to ...
1
vote
0answers
158 views
How to debug 'Layer is not valid error' from Python plugin?
I'm trying to understand what goes wrong with a QGIS python plugin.
Basically I'm trying to render a series of POINT.
The query works fine, at least giving it by hand from inside PostGIS DB:
"SELECT ...
2
votes
1answer
621 views
TIN Interpolation using a vector layer
I'm writing a plugin in QGIS and I'd like to generate a TIN surface using a vector layer with x,y and z (interpolation attribute).
The idea is to visualize the same result like in the Interpolation ...
5
votes
1answer
128 views
How to debug a QGis python plugin
I'm trying to write a python plugin for QGis. I'd like to debug some DB queries and I need a way to display the result.
I thought about using a popup to display it, but I don't know how to show a ...
11
votes
0answers
247 views
Python Plugin Development in QGIS: How to access label text?
I'm trying to create some custom labels for point features in a QGIS point vector layer, and I want to write a python plugin to do it. We need our labels to be presented with color tinted rectangles ...
1
vote
1answer
55 views
Can't find the New label tools in QGIS
I can't find the New label tools in QGIS developed by sourcepole. I'm using QGIS 1.7.4. Is it a QGIS tool or a pluggin?
Thanks!
2
votes
1answer
145 views
Unit of $length in QGis Field Calculator
I'm calculating field of various features in my shapefile using QGis.
I'm getting some sample length as 0.134914579766986.
I want to know in what unit (eg: meters, km etc) is the above value ?
1
vote
2answers
71 views
Length of Feature
I have a shapefile which renders a map.
I want to calculate and preferably store length of each feature in the shapefile either using QGis or through programmatic means.
What is the best way to get ...
0
votes
0answers
83 views
Road Graph Route not Touching Start and End Points
I am trying to find the distance between 2 points using Road Graph. After I enter the points' coordinates and hit calculate, the route comes up but is not touching either point, and usually it is not ...
2
votes
1answer
106 views
How to move the QGIS Layerpanel/Dockwidget programmatically
i'm working on a QGIS-plugin and want to move the default LayerPanel/Dockwidget to somewhere else programmatically. More specific: i want to move it into a tab of my tabwidget.
Is this possible? How ...
2
votes
2answers
84 views
Cannot add Plugins from Python: “Plugin is Broken”
I'm using the latest version of QGIS on a Windows 7 (32 bits), and when I try to add a plugin from the option "Fetch Python Plugins", it simply cancels the installation and I can see the following ...
1
vote
0answers
46 views
Error reading repository: QGIS Official Repository HTTP request failed
I can't seem to access the plugin repository.
Is this an issue with my system or is there something going on at the server end?!
I get the following error as wells sometimes a window saying: "Error ...
0
votes
0answers
63 views
Why are my combo boxes not filled with a list of layers?
I am developing a Qgis plugin (layer_gui) and I am having a problem with populating the list of layers. When I first run the plugin my combo boxes are not filled with a list of layers, I have to ...
3
votes
1answer
127 views
Does QGIS DB Manager plugin lock PostGIS transactions?
I do most of my geospatial analyses in PostGIS 2.0 using PgAdmin III. I use QGIS 1.8 for visualizing my data but also for querying my database using the DB Manager plugin.
Sometimes (quite often ...
6
votes
1answer
57 views
How to get info from selected object?
I am new to the Quantum Plugin development and wonder if there is more information about the following.
I have added a shape file and am (off course) able to select a point from this shape file. In ...
3
votes
1answer
246 views
Which parameter values should I use with QGIS Heatmap plugin?
I've read all the posts and docs about the heatmap plugin but can't seem to get it to work.
The map is the size of the United States and has a little over 2000 points. I've tried small radi (1 ...
1
vote
1answer
81 views
QgsVectorDataProvider.createAttributeIndex() fails in QGis 1.8
Adding an Attribute Index to a Shapefile fails for a Python Plugin in QGIS:
For example - the following python Code in a Plugin
ly = QgsVectorLayer(data_source, layer_name,"ogr")
prov = ...
2
votes
1answer
86 views
plugin 'hook' when writing with Python
Just a conceptual question... when writing a plugin using Plugin Builder 1.8.3, where does the script get connected to the application instance objects?
As an example (taken from ...
1
vote
1answer
89 views
Is there a straight way to copy or clone a QgsVectorLayer Object?
Is there a straight way to clone or "deepcopy" a QgsVectorLayer Object with python? Unfortunately the python module "copy" is not successfull with that.
Thanks in advance!
nikolaus
3
votes
1answer
159 views
Where is the Road Graph panel?
I am trying to use the road graph plugin within qgis 1.8 (running under windows 7 64 bit). when I click vector-> road graph -> settings I get the settings-panel:
But, I dont know how to enable the ...
0
votes
0answers
33 views
QGIS Plugin delete QGSVertex from map canvas
i'm developing a qgis plugin and i need to add a function to delete previous drawn vertexes on map canvas.
On my dialog class, i can draw vertexes and when i draw one i'm also adding it to a list, so ...
2
votes
1answer
194 views
How to meet “Contour plugin” and “Profile Tool” dependencies in OSX?
So I have two similar but different issues than my previous question, one I may have mentioned already. When attempting to install the Contour plugin I am told I need matplotlib, which I have on my ...
1
vote
1answer
137 views
QGIS Profile from Line tool requiring shapely.wkd?
I am trying to install the Profile from Line tool for QGIS, and the system informed me I need shapely.wkd. A search on the QGIS site for shapely takes me to the Contour Plugin...can anyone help me out ...
2
votes
1answer
204 views
QGIS GDALtools plugin problem
I am trying to use the GDAL merge tool and receive the following error message:
The process failed to start. Either the invoked program is missing, or
you may have insufficient permissions to ...
2
votes
0answers
50 views
Is there a way to distinguish between digitized and pasted features?
Is there a way to tell if an added feature in QGIS is in fact a newly digitized one or a pasted feature?
I think QGIS is treating both cases in the same way, emitting the same signal:
...
4
votes
2answers
108 views
What is the fastest way to iterate through a list of features?
I have written a QGIS plugin and it iterates through all features in a layer using provider.select() and compares geometry. The problem, the plugin is very slow. If there are 114 features in a ...
4
votes
1answer
62 views
Is it possible show the feature attributes dialog when I add a feature in code?
I want to know if it is possible to make the feature attributes dialog in Qgis show up when I add a feature by code using:
QgsVectorLayer::addFeature( tFeature )
This is available when I add ...
1
vote
0answers
264 views
QGis CadTools CAD Console
I need help with the Qgis CadTools CAD Console commands.
According to these help files there are six commands. I just can't get them to work.
Can someone help me?
Thanks
3
votes
1answer
57 views
How to use the QgsDiagramRendererV2?
I'm writing a plugin for QGIS in python
in the QGIS API doc, I can see the QgsDiagramRendererV2 class, under the qgs.core section
http://www.qgis.org/api/classQgsDiagramRendererV2.html
What I'm ...
2
votes
0answers
126 views
Postgresql Query Plugins Not Returning Results in QGIS
I'm using the Fishnet function as described here to create a grid.
If I use the following SQL to call the function to position a grid where I want it (I'm using NZGD2000 SRID = 2193) the query ...
7
votes
2answers
193 views
How to run a spatial query with a raster and vector layer in QGIS?
I have a soil map (vector-polygon layer) and a map of the crops farmed in the same area (raster layer, from the US Cropland Data Layer).
I would like to calculate for a given soil type, the surface ...
3
votes
1answer
122 views
How to get raster layer pixels contained in a shape defined in a vector layer
I am new in QGis python plugins dev and I have a "maybe stupid" question (in the title :-) ).
I try to retrieve pixels (from a raster layer) which are "contained" in a polygon defined in a vector ...
2
votes
1answer
88 views
Qspatialite plugin problems with queries using inner join
I'm trying to create a layer in QGIS from a sqlite database using a query from 2 tables: one has spatial data and the other doesn't.
When I build the query using Qspatialite using the 'Advance SQL ...
0
votes
0answers
61 views
How to debug problems with Terrain profile plugin?
I am trying to use the terrian profile plugin to create a profile of a lake but at the moment i am just trying to get it to work with a DEM I have.
However I am only getting outputs that make no ...
3
votes
2answers
655 views
How to reproject a vector layer in QGIS?
I have some shape file which is in UTM. I wanted them to convert to Decimal Degreesin QGIS.
Hope I can get some better response..
Thanks.
2
votes
0answers
36 views
QGis, add dialog and classes to plugin
what are the steps to add files that represent a uidialog(draw with QTDesigner), and add the necessary python class files, using the default makefile provided with qgis plugin builder?
thanks,
