Python bindings for QuantumGIS (QGIS)
0
votes
1answer
29 views
Make many lines in one layer (Python)
I what to create many lines with this code:
v_layer = QgsVectorLayer("LineString", "cable", "memory")
pr = v_layer.dataProvider()
seg = QgsFeature()
...
0
votes
2answers
58 views
Python to get ids from shp dont return all records
I have some Python code to get the ids and georeference from a shapefile:
canvas = qgis.utils.iface.mapCanvas()
allLayers = canvas.layers()
nos = QgsFeature()
for i in allLayers:
if ...
0
votes
1answer
68 views
How to convert geometry of SHP to decimals
I try to create a line with two points. These points are obtained in a SHP layer.
How can i convert that points to decimals?
Thank you
0
votes
1answer
24 views
How to use expression in QgsVectorlayer label by using python?
how to show the two field values as a label on features. I have done it for a field called "ErrorDescr" with this i need to show another field values. Other field is "MarkerId"
...
1
vote
1answer
53 views
How to use QgsOverlayAnalyzer class in pyQGIS?
I am very new to Python scripting in QuantumGIS, so bear with me please.
I am trying to use the QgsOverlayAnalyzer class in QuantumGIS (http://www.qgis.org/api/classQgsOverlayAnalyzer.html#details) ...
2
votes
1answer
54 views
How to see print commands through Python Script while programming plugin for QGIS?
This might sound like a silly question.
Is there a way that from running a custom plugin made for QGIS that a Python Shell can appear along when the plugin is run, like a debug screen. I'm asking ...
3
votes
1answer
74 views
How can I programatically create and add features to a memory layer in QGIS 1.9?
I had a working plugin in QGIS 1.8 which read data from an MSAccess database and added it to a series of memory layers. There is some processing involved in the interim so I don't think simply using ...
6
votes
1answer
118 views
How to address the new “Task-Completed” QgsMessageBar in Python?
I am really amazed what huge steps the QGIS development has taken in the last months. The new iconset, the improved Print composer and many more changes to be seen in QGIS 2.0 are really awesome!
...
1
vote
2answers
88 views
Where exactly are qgis.gui and qgis.core located?
I'm trying to create a standalone qgis app using pyqgis, i'll be deploying it by copying the install folder of qgis and source folder of my app, and so for the testing purposes i copied qgis install ...
0
votes
0answers
17 views
QGis non blocking notifications with pyqgis [duplicate]
I'm searching for the way to use the new QGis non blocking notification system with the QGis python wrapper. I found informations on this fonctionnality but nothing on how to use this especially with ...
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 = ...
1
vote
1answer
383 views
rpy2 installation ERROR “Tried to guess R's HOME but no R command in the PATH”?
I tried to install rpy2 (pip install rpy2). I want to use the SDAPP4 extension with QGIS (QGIS shows up the message missing rpy2...). The system tells me always the same error: Tried to guess R's HOME ...
7
votes
4answers
616 views
How to run sextante algorithms outside of qgis python console?
I'm kind of stuck trying to figure out the way to run sextante from a standalone python from OSGeo4W distribution. The reason I want to do this is that I got tired entering parameters in the dialog ...
0
votes
1answer
52 views
How to set Marker Line symbol for QgsVectorLayer by using Python?
QgsVectorLayer Right click->Properties->Style->Single symbol->click on simple line in tree node ->symbol layer type -> Marker line
Kindly help me to set marker line symbol programmatically by using ...
1
vote
1answer
44 views
How to get CRS of a raster layer in pyqgis?
I have this problem accessing to the coordinate reference system(crs) of a raster layer map.
I wonder if such thing is possible?
I have used this xml from GDAL open map service to load in a raster ...
1
vote
1answer
43 views
Understanding the QGIS API documentation to write python code
I am not sure how to use the API documentation to code in Python.
For example, I want to determine whether a layer is a point, line or polygon layer and found the following in the API documentation:
...
1
vote
0answers
17 views
How to align QProgressBar label in QGIS messagebar? [migrated]
Unable to align the QProgressbar label in Qgis Messagebar. see the image below
While progressbar is updating,the label is vanished. so i tried the alignment for progressbar as shown below but its ...
2
votes
1answer
76 views
How to add one or more points to an existing polyline or polygon?
Using the following code, I make a polyline with two points.
vl = QgsVectorLayer("LineString", layerName, "memory")
pr = vl.dataProvider()
vl.startEditing()
fet = QgsFeature()
...
0
votes
1answer
51 views
How to save after using fet.setFeatureId in pyQGIS?
By using the following code, I want to change the id of the line when saving the line. But the setFeatureId command, gives a false when doing the commitChanges(). Any idea how to change the id?
vl = ...
1
vote
2answers
150 views
PyQgis overwrite shape file and adding layer to Qgis
I am creating a shapefile in python by:
driver = ogr.GetDriverByName('ESRI Shapefile')
datasource = driver.CreateDataSource('c:/temp/toke2.shp')
layer = ...
2
votes
1answer
165 views
Is it possible to programmatically add calculated fields?
In the Memory provider described in PyQGIS Cookbook or in question How to create a new empty vector layer programmatically? I can see how to create a vector layer programmatically using standard ...
0
votes
2answers
70 views
How to make line with arrow head in QgsVectorLayer using python?
I need to draw line with arrow head or after drawn the line i need to make it as arrow head line by using python. or can we set any arrow head symbol for line features by using python?
Kindly help me ...
3
votes
2answers
193 views
How to automatically reloaded raster layer if source is changed in QGIS?
How to automatically reloaded raster layer if source is changed? (The path is the same but inside source file are changes)
I use:
qgis.utils.iface.mapCanvas().refresh()
but layer not refresh.
#
...
0
votes
0answers
56 views
How to use more than one QT form in Qgis Python? [closed]
I need a help to use multiple qt forms in PyQgis. For example, i need to open one qt form after the login form.
I tried like this:
from PyQt4.QtCore import *
from PyQt4.QtGui import *
from qgis.core ...
1
vote
1answer
88 views
How to evaluate raster calculator expressions from the console?
How can I execute from the console an expression that should be used with the raster calculator?
I'm searching for something like this:
qgis.someRasterCalcClass.evaluate("boh@1 + boh@2", ...
6
votes
1answer
438 views
Is there a way to access QGIS plugins in Python?
Is there a way to access QGIS plugins in Python? I'd like to write a script to do some geoprocessing, and I'd like to use the clip, regular points and convex hull tools in fTools, as well as the Road ...
0
votes
0answers
43 views
qgis python app how to add edit feature button?
I'd like to develop a QGIS Python app for plotting points and editing the attributes. I've started with the tutorials here: http://blog.qgis.org/?q=node/59 and read the cookbook ...
4
votes
1answer
93 views
Speed of editing attributes in QGIS from a Python plugin
I'm trying to edit the value of an attribute for each feature in a layer using a QGIS Python plugin. I've found that doing this outside of editing mode is much slower than while editing (even ...
1
vote
1answer
58 views
open QGIS project with parameters
I am looking at a piece of work to deploy QGIS as the standard within an organisation. There is an existing piece of software that I need to link to QGIS so that when a button is pressed within the ...
7
votes
1answer
148 views
How to draw perpendicular lines in QGIS?
I have a situation like this:
What I need to do is to connect each point to every line that is at most, let's say 200 m, away from the point. In other words, I need to draw a perpendicular line ...
1
vote
1answer
57 views
How to add MS SQL table using python console?
I have MS SQL Server 2008 R2 database. How to add MS SQL Table using python console in QGIS?
3
votes
1answer
75 views
How to find the nearest line to a point in QGIS? [duplicate]
My question is that given a point and few lines, how should I go about finding the nearest line to the point?
I am aware of How to I find the nearest line to a point?, but that isin ArcGIS and ...
1
vote
1answer
64 views
How to “Merge Selected Features” with python?
I have been looking for the answer to this question for some time now, but can't seem to find it! My problem is straight forward:
I have one layer
It contains lots of features (only polygons), say ...
1
vote
2answers
82 views
Creating QGIS layers in python console vs stand-alone application
I am having trouble creating a QGIS vector layer in a stand-alone python script while exactly the same code works fine in python console inside QGIS. The following code results in a proper ...
4
votes
4answers
111 views
How to display a “Save As” dialog for raster files?
I'm writing a QGIS plugin in python. I need to show a "Save as" dialog window in order to allow the user to select the path of the output raster file. Do I need to create a QFileDialog and manually ...
4
votes
1answer
55 views
Can I add entries to the layerlist context menu?
I am implementing a python based plugin for use with QGIS 1.8.
Most of it's user interface is contained within a QDockWidget but there are some layer specific controls I would like to append to the ...
7
votes
1answer
124 views
Is it possible to show our custom message in QGIS Status bar using python?
Is there any way to show our custom message in Qgis Status bar using python? Just like in arcgis "IApplication.statusbar.message(0) = "Please wait..."
like that is there any option to show ...
3
votes
1answer
186 views
Creating Selection MapTool in PyQgis Custom Application
I'm developing a custom GIS application using PyQgis API.
How can I let the user select features on the map using Maptools? I would like to replicate the select feature there in Qgis to make the ...
1
vote
1answer
46 views
How to get a message when the map is moved in QGIS?
I want to get a message when every time I move the map.
I had:
def info(self):
QMessageBox.information( self, self.tr( "Info" ), self.tr("info") )
I suppose that used to be something like ...
1
vote
1answer
54 views
Joining table to shapefile with pyQGIS
Joining shapefiles is a relatively straightforward proess in QGIS using 'add vector join' in the layer properties menu. I can add a csv file as a vector layer, as well as a shapefile, and join the two ...
3
votes
1answer
64 views
How to calculate all paired shortest path using PyQGIS?
The code for shortest path analysis with PyQGIS specifies start and end nodes explicitly:
pStart = QgsPoint( -1.37144, 0.543836 )
pStop = QgsPoint( -1.1027, 0.699986 )
...
2
votes
0answers
51 views
Python Script that calls the Voronoi Polygons Function?
I've been looking to see if there was a way to call Voronoi Polygons function found in Vector/Geometry Tools, directly from the code but I have not found one. Does this currently exist? Is there a way ...
2
votes
2answers
69 views
How to determine the coordinates of the corners of the raster layer
How can we determine the coordinates of the corners of the raster layer? The image opens function QgsRasterLayer.
0
votes
1answer
54 views
How to handle adding a PostGIS layer in pyQgis without saving password?
I'm writing python plugin and trying to find the right way to add PostGIS layer on the map without storing user password.
After adding layer on the map, I strip out the password from uri like this:
...
6
votes
1answer
97 views
How to save python session in QGIS?
After running a lot of scripts in QGIS' python console, I have more than 10 dictionaries and lists, and I need these for further analysis. Is there a way to save python session, with all these ...
1
vote
1answer
78 views
How to store selected attributes of vector layer using PyQGIS
I'm following this PyQgis workshop:
http://www.qgisworkshop.org/html/workshop/python_in_qgis_tutorial2.html#accessing-data-attributes
I have a point layer shapefile. I want to be able to retrieve and ...
3
votes
2answers
90 views
How to write an equivalent to MapBasic's CreateLine in pyQGIS?
I know this kind of question has been asked, in part, before - specifically: Seeing QGIS Python Commands and: How is object created as line using createline stored in .tab file?
but this is a specific ...
2
votes
1answer
39 views
How to check if two qgsPoints are equal in PyQgis
I have two points:
a=QgsGeometry.fromPoint(QgsPoint(227739,908343))
b=QgsGeometry.fromPoint(QgsPoint(227739,908343))
but when I run:
a==b
it returns False.
What am I doing wrong?
Update:
it ...
1
vote
1answer
60 views
How to get vector feature by mouse location?
I'm writing a photo grouping plugin. My current problem can be broken up into "end goal" and "baby steps", because I think that's what I want. But if there's a way to get to the end by a different ...
5
votes
1answer
312 views
How do I allow users to select features with the mouse?
I am using PyQGis API to create a custom application.
How do I allow users to select features with the mouse? Is there a mapTool for this? Surely with a product as powerful as QGis there must be.
...
