Questions tagged [qgis-2]
Version 2.x of QGIS (previously Quantum GIS)
350
questions
37
votes
7
answers
46k
views
Fixing geometry validity errors in QGIS 2
I am working on ownership data at a US county level. I have one shapefile per county that contains thousands of tax parcels. I need to dissolve the polygons representing parcels owned by the same ...
41
votes
4
answers
65k
views
Loading OpenStreetMap data in QGIS?
In QGIS 1.8 I used the openstreetmap plugin to request data from the server, or open a .osm XML file, which produced 3 layers (polygons, polylines and points) in QGIS.
This was great (give or take ...
15
votes
2
answers
22k
views
Completely uninstalling and removing QGIS 2.8.1 on Windows Vista
I want to uninstall and completely remove QGIS installation from my computer (Windows Vista). I have uninstalled it and when i try to reinstall it says it is already installed on the system.
13
votes
4
answers
7k
views
Styling border to match fill in QGIS?
In the past I have just manually matched the color of the border to the color of the fill, but this can be time consuming.
I am wondering, is there any way to have the program automatically match ...
8
votes
5
answers
22k
views
Creating DEM from LAS file without using LAStools?
I want to create a ground model from a *.las file. The LAStools are available in QGIS but limited in use (generation of black diagonal in result file), so I can't use this.
In the GRASS tools I can ...
11
votes
5
answers
16k
views
Creating compressed GeoTIFF with QGIS Clipper tool?
I have a geo-tiff created by Pix4D which is about 375 Mb in file size.
I have clipped it to a smaller area using Qgis 2.8(using Raster ‣ Extraction ‣ Clipper), and the output file is about 900 MB in ...
11
votes
2
answers
7k
views
Loading composer from template and generating atlas using PyQGIS
I am trying to build a plugin to load a print composer from file, generate an atlas and export to image. So far I have been successful in loading the template and exporting it to image.
I have been ...
7
votes
2
answers
2k
views
How to generate multiple maps where one highlighted attribute changes?
I have a layer that contains counties within the state of Washington.
I need to build one map (jpg) for each county. For that specific map all counties will show as light grey, but the specific ...
10
votes
2
answers
8k
views
QGIS 2.4 access .mdb add error
So I followed the instruction here: Can QGIS read an ODBC connection? for adding a .mdb into QGIS. There are great instructions about 1/3 of the way down. But I still can't get it to open. I on ...
5
votes
2
answers
750
views
Calculating point layer values within polygon features in QGIS 2
There are two layers
polygon 'BereichBerechnung' with a field "Are_Number"
points 'EW2017' with a field "EWjeAdr"
In QGIS with a Virtual Layer, I want to calculate the sum of the ...
4
votes
1
answer
366
views
Line width and labels based on blended values of features sharing same geometry in QGIS
I want to appropriate line segments that share the same geometry with a particular line width and labels based on the aggregated values of one field "GIS@BUS_5_Min".
My attribute table and ...
34
votes
2
answers
19k
views
Does QGIS have the equivalent of ArcGIS's Layer (*.LYR) file?
Using ArcMap, it is possible to add a dataset (eg a shapefile) to the map, and configure the layer's properties (such as the symbology, table joins, switching some attributes off in the Identify ...
21
votes
2
answers
17k
views
How to draw polygons from the python console?
I've been visiting and revisiting the page on geometry handling in the PyQGIS Cookbook: http://documentation.qgis.org/2.0/en/docs/pyqgis_developer_cookbook/geometry.html but can't seem to figure out ...
10
votes
2
answers
2k
views
Representing uneven tree canopy spread around point in QGIS
I am trying to make an attribute to show the uneven spread of the crown of a tree using the four cardinal points. I can use a buffer to show one feature, in this case a root protection area. But I ...
10
votes
1
answer
7k
views
Counting points in polygons using QGIS
I want to count points (1000 of students home) in district polygons with Qgis 2.16. I didn't find the tool in the analysis tools plugin.
Is there another plugin or method I could use to perform this ...
9
votes
2
answers
1k
views
Adjusting flow map styles in QGIS 2
In one project, I am trying to adopt marvellous styles for flow maps created by @underdark.
At this moment I have the following output
Shapefile was created with the usage of Flow maps (Oursins) ...
6
votes
2
answers
10k
views
Terminating Python scripts in Processing framework
I'm writing a Python script to use it in Processing framework. I need to cancel script execution if certain conditions are met (to save user's time). I tried to use sys.exit(arguments) command. The ...
4
votes
1
answer
3k
views
Adding WMS layer in QGIS standalone Python script [closed]
How do I add a WMS layer on a map, in a standalone Python script with QGIS 2.4?
The methodology explained at the bottom of the official QGIS documentation page seems to be outdated and does not work:...
12
votes
3
answers
13k
views
QGIS 2.14 standalone GRASS provider missing Msys folder, can't execute tools
In QGIS 2.12 and down, when one went about manually setting the GRASS provider folder paths, this was the way to do it
In GIS 2.14 there is no Msys folder in the same path (...\apps\msys) or any ...
11
votes
1
answer
29k
views
Creating DEM from Point Data using QGIS?
My boss gave me a small 3D-point-shapefile and asked me to make an DEM from it, which I should put together with an older DEM of the same site, which was made with Surfer.
I created a raster-layer ...
8
votes
2
answers
2k
views
Is it possible in QGIS print composer to include a numeric scale in an html box?
For work I always have to create a table with my name, project name, date etc. into my map layouts. I also need to include the scale like "1:150000" in that table.
So far I am solving that by ...
4
votes
4
answers
3k
views
Identifying features with duplicate geometry in QGIS
I am working on a public transport network in one shapefile (polyline type) in QGIS 2.18.
Certain bus routes share the same paths, means that one line-part can repeat more than once. It always has the ...
13
votes
3
answers
3k
views
Is it possible to use memory layers in QGIS processing algorithms?
I am building a QGIS plugin that connects to a MySQL database in the local network, and then adds a subset of one of the tables to an in-memory layer; the subset is based on data currency (only taking ...
13
votes
3
answers
21k
views
Missing processing menu in QGIS
I'm sure there is a really simple explanation to this but haven't found any pointers on this forum or elsewhere. I seem to have lost the 'Processing' menu from QGIS and can't figure out how/why!?
Any ...
11
votes
2
answers
9k
views
Opening Raster stored in Esri Geodatabase using QGIS
Is there a way to open a raster that is stored in ESRI V10.0 Geodatabase in QGIS V2.4?
I can open the vector layer, but there does not seems to be a way to open a raster.
11
votes
3
answers
3k
views
Connecting points (bus stops), which don't lie on lines (LINESTRING), to network?
I need to connect bus stops (points) to a network layer (OSM data). These bus stops do not lie directly on the lines (see screenshot) nor should their location be moved. I use PostGIS, pgrouting and ...
10
votes
2
answers
6k
views
Does mapCanvas().refresh() not work in QGIS 2.6?
Before I used the function
qgis.utils.iface.mapCanvas().refresh()
to reload the map canvas after for example a layer color was changed from a plugin.
But this is not working with QGIS 2.6 for me.
...
8
votes
2
answers
5k
views
Skeletonize vectors in QGIS/Python
I am trying to find a tool to create a skeleton of a large vector dataset using QGIS and its bundle. It should be directly programmatically callable through Python or commandline (QGIS, GRASS, OGR etc....
7
votes
5
answers
41k
views
Enabling SAGA in QGIS?
A similiar question has been asked recently as How to make GRASS and SAGA tools capable to use in QGIS?
However I have some specific queries and process I have tried which are probably better in a ...
6
votes
1
answer
2k
views
Making serial maps from template using PyQGIS?
I have developed a stand-alone python script for making serial maps using PyQGIS library.
The maps should follow a specific format that is indicated by a template .qpt file.
This template file is ...
4
votes
5
answers
11k
views
Area is calculating wrong using $area in field calculator (QGIS 2.8.1-Wien)
There is a similar question posted, but the solution to it seems to be that polygons were multipart:
Wrong $area from field calculator (QGIS)
In my case, all polygons are singlepart. I have several ...
3
votes
1
answer
1k
views
QGIS just installed on MAC OSX - vector layer styles do not work properly
I am a newbie with QGIS - I have just installed QGIS 2.10.1-Pisa. I am following a youtube tutorial by Steven Bernard and I just found that the styles do not work properly (I run Mac OS X Lion 7.5.1. ...
18
votes
2
answers
9k
views
Save and load user profiles in QGIS
Is there a way use a configuration file, maybe .ini to load in the relevant settings for QGIS when it is setup, maybe to share with various people?
Plugins installed and plugin repositories filled in
...
13
votes
4
answers
4k
views
Is it possible to set up a local QGIS Plugin repository?
I've developed a couple of custom QGIS Plugins for use by our office. I can't post them to the official QGIS Plugins repository as they reference/utilize sensitive data on our own servers.
For ...
13
votes
4
answers
30k
views
Fixing polygon self-intersection in QGIS?
I am attempting to mask a raster to US Forest Service boundaries in QGIS. It fails due to self - intersections of polygons.
Warning 1: Ring Self-intersection at or near point -109.90112962000001 43....
11
votes
2
answers
2k
views
Couldn't load plugin 'processing' on Windows 7 64bit
I installed QGIS (2.0.1-Dufour Dufour, d94c044) using both the stand alone installer and the OSgeo4w installer and seem to have an issue with the processing plugin. At first I thought that there was a ...
8
votes
4
answers
69k
views
Fixing Runtime Error R6034: application has made attempt to load C runtime library incorrectly?
I just downloaded QGIS 2.0 and every time I open it I get this error message window popping up:
Does anyone know what this means or how I might be able to fix it?
8
votes
3
answers
3k
views
How do I set layer transparency in QGIS 2.0 with Python?
I have a raster layer loaded in QGIS 2.0 and I'd like to be able to set its transparency via the Python console. I'm new to the API and have not been able to find out how to do this.
Here's what I ...
7
votes
1
answer
5k
views
How to style a vector layer in QGIS using hexadecimal color code stored in attribute?
I have a polygon shapefile storing hexadecimal color codes in a specific attribute.
gid | label | color
---------+-----------+------------
1 | Crops | #FF5F2C
2 | Forest ...
6
votes
2
answers
8k
views
Creating multiple select dropdown list in QGIS
Is it possible to create a multiple select dropdown list/select widget in QGIS which links to a separate txt file?
I want to collect species lists for different locations in QField but do not want to ...
2
votes
2
answers
2k
views
Dividing shapefile into multiple shapefiles using an attribute value in QGIS Graphical Modeler
I have a shapefile with a column that have project references, I want to create a different shapefile for every project reference there is.
Note that the project references are not unique in the sense ...
2
votes
1
answer
371
views
Inherited values between polygons in QGIS [duplicate]
In this project, I have three polygons, see the image below
'Polygons_From', includes input attributes, i.g. "Value_1", "Value_2", "Value_3", and $area for each quadrate ...
2
votes
1
answer
4k
views
How to randomly select from existing points within each polygon?
I have a polygon layer (where each feature has a class attribute), and a point layer, and there are at least 10 points within each feature of the polygon. Is there a way to randomly select only "...
1
vote
1
answer
414
views
Workarounds for heatmap plugin in QGIS?
In QGIS 2.8, the heatmap plugin got CRS broken. I updated to 2.10, now in the plugin the dialog is broken: it does not let you choose the format.
I render layers for atlases with heatmap style. But I ...
-2
votes
1
answer
12k
views
Easy way to create buffer in QGIS 2?
In the old version of QGIS creating buffer was a relatively complicated task.
Basically you had to save your layer as a new one with metric cylinder CRS in order to calculate distance correctly.
If ...
15
votes
1
answer
4k
views
Wait for canvas to finish rendering before saving image
I am attempting to write a script that will save a rendering of several layers using the map composer. The problem I am encountering is that the script saves before qgis has finished rendering all ...
14
votes
1
answer
36k
views
How to change the type of a column of an attribute table in QGIS? [duplicate]
So I want to change one of the columns in my table from string to real. How am I supposed to do that?
14
votes
2
answers
17k
views
Getting field names in PyQGIS
I am trying to change an plugin from QGIS 1.8 to 2.0.
In the 1.8 version I create a table of the field names like this:
layer = vlayer
provider = layer.dataProvider()
feat = QGSFeatrue()
allAttrs = ...
13
votes
7
answers
55k
views
Shapefile layer no longer editable (toggle edit option greyed out) in QGIS
I am using QGIS 2.16 / Windows 10.
I have a point shapefile which I have been using for a little while that has always been editable.
Today I was editing the layer, saved my edits and left my ...
12
votes
2
answers
9k
views
How to format labels with leading zeroes?
I'm trying to display a number next to a symbol in QGIS 2.0.1 - The numbers are from an integer-field in a PostgreSQL database.
The goal is that single digit numbers get a leading 0 (zeros). Examples:
...