QGIS is a cross-platform GIS application licensed under the GNU General Public License.

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23 views

QGIS Python variable not updating properly after layer data is saved

This problem is a continuation of this one I am running a little script on OpenProject event that sets the feature id automatically after a new feature is digitized. Code: def openProject(): from ...
2
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0answers
21 views

Why PyQt http request works in QGIS console, but not in a plugin?

I want to send http request in a QGIS plugin using PyQt. I found in this post working syntaxes to do so, but something odd occurs. The script given in the question works both in the console and in my ...
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0answers
27 views

QGIS snapping to the points of a line or polygon you are just creating

I have the snapping option enabled. I can snap to any point, intersection of created lines. But I can't snap to any vertex of the linestring I am just digitizing. Is there any option/plugin to ...
2
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1answer
91 views

How to search for a text from column1 in column2 in QGIS?

I have street names in a column (column1) as well as in another one (column2). I would like to write a selection expression to find out if there are similar street names (or parts of the names) ...
0
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1answer
24 views

Couldn't destroy QGIS Custom Edit Form Factories

I created custom form factories using this tutorial. However, the factory destructor QgsEditorWidgetRegistry(). However, it doesn't destroy them. I just used the above destructor at the beginning of ...
1
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0answers
23 views

Setting default encoding for python in QGIS in Windows

I have a problem that I have been working on for too long now... I am creating a python plugin for QGIS and I have problems with encoding. Characters with accents are displayed funky, but it is fine ...
2
votes
1answer
43 views

How can the gridlines in QGIS be set to be curved lines (neat circles) around polar region (azimuthal projection)?

I am trying to present a map of our polar regions using QGIS software. I am using an azimuthal (polar) projection. I have added a graticule (gridlines) to the map as a background, which are at 10 ...
2
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2answers
392 views

How to create a polygon fill as seen in the QGIS 2.16.0 changelog?

The polygon fill for 'Urban parcels' in the following .gif animation looks really cool. http://changelog.qgis.org/media/images/entries/5817785cf3d18db78669c2eb2c2be0cf606c3783.gif (See also: http://...
3
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2answers
46 views

How can a statistically significant difference between rasters be calculated?

so after some gruelling use of MaxEnt I have four occurrence probability rasters for the four quarters of the year, each one is about 70MB+. I want to test whether they are significantly different ...
3
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0answers
47 views

QGIS QgsAttributeTableModel only loads when called without a function in Python

I tried to load QgsAttributeTableModel into QgsAttributeTableView or a plain Qt QTableView but it could run from inside a class method or function but it runs without any function or method. Below is ...
3
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1answer
44 views

How to generate random points that lie on a line in qgis?

I have a shapefile with track lines and I need to generate random points from each 1 km of every line. There is a function in QGIS Random points but it offers to generate random points only inside a ...
3
votes
1answer
41 views

GRASS on QGIS is generating new CRS

I am experiencing a strange problem by using the GRASS toolbox on QGIS 2.14.3 Essen. Even if in settings>options>CRS I select to use the project CRS when creating new layers, the results of GRASS ...
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0answers
25 views

Using Postgresql/PostGIS/Pgrouting in PYQGIS Processing Scripts

I have started exploring PYQGIS scripts and learning writing PYQGIS user scripts in python. I want to use pgsql/postgis/postgresql in the script. Please suggest Also Can anyone suggest That the ...
1
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1answer
46 views

Why doesn't Dissolve with stats plugin work in QGIS 2.14?

In ArgGIS 9.3 there is a function of ArcToolBox named Summary Statistics (Analysis). I'm finding a similar function on QGis. One of these is Dissolve with stats (plug in) but on my version of QGIS (...
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0answers
34 views

QGIS options menu causes freeze on Ubuntu 16.04, solutions?

First time asking, I've checked the internet and no luck. I am unable to edit the program options in QGIS 2.14.3 running on Ubuntu 16.04 (settings -> options). I've uninstalled all QGIS packages (...
4
votes
1answer
78 views

How can I specify a Minimum and Maximum Word Wrap length in QGIS?

I want my labels to fit nicely within polygons. Based on this answer I discovered the power of the wordwrap function in QGIS to make labels. However, I'm confused as to how I could specify a minimum ...
0
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1answer
33 views

pgrouting to calculate distance using a chosen highway system

I am working on a research to calculate the distance of firms (scattering around the nation) to several metropolises via selected national highway system. Then I overlay the highway map with firms' ...
3
votes
1answer
35 views

How to convert multipoint layer to polyline layer in QGis

How can I convert a multipoint layer to polylines layer in QGis. I am looking for a tool equal as the GeoWizards (convert > Multipoint to polyline) for ArcGis.
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0answers
14 views

How do you test QgsDataSourceURI.setConnection is valid in a QGIS plugin?

I am currently trying to write my first Python plugin for QGIS and I'm using the the uri = QgsDataSourceURI() uri.setConnection(host,port,db,username,password) syntax to create a connection to an ...
1
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1answer
24 views

How do I control the behavior of the QMessageBox

I'm working on my first plug-in. In an attempt to validate the user selections on the dialog, I am using a message box to return messages to the user if an error is found. The messgae box displays ...
1
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1answer
21 views

How to reimport/copy a shapefile where attribute table can be subsequently edited without changing original shapefile in QGIS

QGIS 2.8.9 I am having trouble when duplicating a shapefile and then going on to edit the attribute table of the duplicate manually. The changes I make are reflected in the original file - hence ...
0
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0answers
21 views

QGIS 2.14 v.what.rast missing

I'm using QGIS 2.14 on Ubuntu 15.10 and missing the function v.what.rat(https://grass.osgeo.org/grass70/manuals/v.what.rast.html). I also installed QGIS 2.14 on Windows where this function is also ...
0
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0answers
44 views

Why do merged rasters in QGIS look 'patchy'?

Poor title for this question, but I can't think of a better way to explain it. I have merged two rasters. I want the joins to be seamless, but there is an obvious line where they meet... I've ...
1
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0answers
10 views

How do I create an inverse-distance weighted attribute mean map?

An attribute-weighted heatmap applies inverse distance weighting to each point in a set proximity and adds them all up. I am searching for a tool in QGIS or another software that allows me to do the ...
3
votes
1answer
33 views

Re-import custom functions without restarting QGIS

I have a python file (in [user]\.qgis2\python) with some functions that I'm working on. It's just a .py file with a bunch of def function_1, def function_2 etc. in it. On startup I import the .py file ...
2
votes
1answer
45 views

import Map from QGIS into QT Designer

I am looking for a way to get a map from QGIS into QT Designer. I have the QT Designer version that comes with QGIS, meaning i have all the standard QGIS Widget. I don´t see a map widget, but many ...
1
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1answer
29 views

Why don't all columns appear when changing style of shape file for cartography in QGIS?

QGIS 2.8.9 I have been working with this shape file and have already successfully coloured it using a graduated style from my column 'TIV' - however recently when I want to change the attribute the ...
2
votes
1answer
35 views

Clipping layer when using new projection in QGIS?

I'm having trouble clipping a shapefile in QGIS so I'll take you through my steps. I've downloaded the land shapefile here http://www.naturalearthdata.com/downloads/10m-physical-vectors/ When I load ...
2
votes
1answer
32 views

Separating a shapefile with specific features into a new shapefile using PyQGIS

I have a shape file. I would like to know if it is possible to classify the different layers in that shapefile (like highways, local roads, rail lines, etc.) with MTFCC and extract a separate ...
4
votes
1answer
48 views

How to create random points in overlapping polygons?

I have a shapefile with ~1840 polygons, many of which overlap. I'm trying to find a way to create 1000 random points per polygon, based on polygon ID. I don't see a way to this using the GUI Random ...
3
votes
1answer
40 views

QGIS problem exporting to both SVG and PDF

I'm having a problem when exporting to SVG and PDF from qGIS. When I open the SVG or PDF in Illustrator, the path of my map is severely cut off with lots of data missing (see below). When I open the ...
4
votes
1answer
51 views

New features to shapefile in QGIS end up with previous features attribute values - why?

When I digitize a new feature to a polygon shapefile in QGIS the attribute data of the new polygon is replaced by the data entered into the last feature created. Has anyone else ran into this issue? ...
2
votes
1answer
37 views

QGIS Field Pyculator Reclass

I'm new to the QGIS Pyculator and need to reclass a field ('AP') based on another field ('Mag'). What I have so far, from the ArcGIS field calculator: def Reclass(Mag,AP): if Mag>= 2000: ...
1
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0answers
15 views

GRASS v.net.iso does not include all lines

I want to define catchment area for bus stops in small city. As a result of v.net.iso in QGIS with GRASS I don't get all highways in that city. Here are my steps: importing above layers into GRASS ...
3
votes
0answers
52 views

Using Check Geometries plugin for polygons in QGIS?

I've a few hundred polygon features with many duplicate nodes, gaps, overlaps and other geometry errors. Fixing all errors seems to be quite tricky. I had to run the duplicate nodes check twice to fix ...
1
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1answer
43 views

Numbering adjacent polygons in sequential order

In QGIS is there a way to assign ascending numbers (attribute) to polygons that are located in a row. The polygons were not created in sequential order.
2
votes
2answers
63 views

Save line geometry as points geometry in QGIS (pyqgis)

I have line and polygon layers. I want to make a list of points' coordinates (ends or begginings of lines), which are touching the polygons. The coordinates which I need are selected as yellow. ...
3
votes
1answer
66 views

OSM data appear in very low quality in QGIS

this is my first map creation attempt in QGIS 2.8.2. I am having troubles in making it look good though with OSM street map data in particular. I import data via the Web>Open Layers Plugin>...
3
votes
2answers
56 views

How to split string (the last digits) in QGIS?

I´m working with QGIS 2.12. Is it posible to split string "from the right side" (it means I needed the last text from every field)? In one field I have description like: new street 25 old street 2 ...
1
vote
3answers
87 views

Convert raster to a CSV values and lat long based on raster value in QGIS

I am looking to convert a raster into a csv file (or tab delimited) based on values in the raster (Value > 0). The csv would have three values, latitude of center of cell, longitude of center of cell,...
1
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0answers
37 views

Creating random points using density-QGIS

I'm trying to generate random points at a specific density within a polygon layer. The polygon layer has 1850 features and I'm looking to have random points within each feature at 1/meter. Going ...
1
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0answers
15 views

QGIS Point Features and Labels Not Appearing in .KMZ/Garmin

I want to produce a Garmin custom map for use with my Etrex 20x. I'm working with QGIS 2.14.3-Essen using the GarminCustomMap, version 1.1, plug-in to produce the output .KMZ on a Mac running OS X ...
2
votes
2answers
42 views

QGIS clipper tool misaliagnment

I'm using QGIS 2.14 and GDAL 1.11.3 and I'm running into a weird error with the clipped outputs. I created a shapefile in QGIS and used it to clip my image. Here's a simplified version of the ...
1
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0answers
18 views

decimals and commas in QGIS - how to display in Qt designer form

I use Qt designer, create a new form, add several line edit (qLineEdit) widgets, rename them the same as the fields in a QGIS attribute table, and save. In QGIS I associate the new .ui file in Layer ...
1
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2answers
73 views

How to Continue a Line Feature in QGIS?

I'm looking for a way to continue a line feature in QGIS. I have checked the Digitizing Tools plugin (both regular and advanced) for a Prolong Line tool, but I haven't had luck. In ArcGIS there's a ...
1
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1answer
23 views

How to load specific PostGIS features from a given table into QGIS?

I have a table in my database built like this: contour_id / (INT) project_id / (INT) contour_lvl / (INT) contour_geom (MultiLineString Geom) Each row in this table is a contour feature associated ...
2
votes
0answers
32 views

Error editing 'editable' view in QGIS

Taking some code from this post, I've been trying to create an 'editable' view in PostGIS. I'd like to store label placement properties in a separate table, build a view of the data I want to use for ...
1
vote
1answer
30 views

QGIS: Automatic shapefile input for pre-constructed automated workflows

I currently have two models running: Take shapefiles and break them down into separate shapefiles based on their class, and save them in a specific folder; Select the broken-down shapefiles with the ...
2
votes
1answer
46 views

Cluster analysis using buffers and polygon features (NOT layer)

I have a point-based vector layer, where each point represents a road accident. I am trying to write a function that: Loops through my accident layer creates a buffer, of a given radius, around each ...
4
votes
1answer
46 views

Representation of Summary statistics in QGIS composer

Is it possible to display a summary of statistics from a certain attribute within a feature class within the print composer using an sql statement. I have an shapefile "projects" with a number of ...