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

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2
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0answers
28 views

Making perfect rectangle in QGIS [duplicate]

I want to be able to set the height and width of my rectangles, as well as the angles. I have been trying the Rectangles Ovals Digitizing plugin, but I can't seem to make it do anything (besides turn ...
2
votes
2answers
41 views

Is it possible to update attribute from spatial join without creating new shapefile?

I have the following shapefiles: county.shp: polygons referring to country land subdivisions lake.shp: polygons referring to lakes, ponds, etc. Layers attributes are as follow: county.shp id ...
3
votes
2answers
44 views

How to preserve the color of a line pattern fill color in categorized vector layer?

I am applying different colors to a vector layer. Now I wanted to improve it, and get some items also with a crossed pattern. I want to have the hatching black, and the colors remaining. All I can get,...
2
votes
1answer
49 views

How to speed up QGIS vector clip?

I'm trying to clip a large polygon shapefile (nearly 440,000 features, 0.5GB) to a shapefile containing a single polygon. Both shapefiles use the same CRS (EPSG:27700). With QGIS, using Vector > ...
3
votes
1answer
26 views

GEOJSON - Transition to cartogram

I have 2 GEOJSON files - 1st contains map of indian states ('India-simple.GEOJSON'), and the second is cartogram based on Gross State Domestic Product of that state ('India-cartogram.GEOJSON'). I ...
0
votes
1answer
26 views

raster sytling multiband rendering 0=nodata

Is there any way to set the pixel value 0 to nodata of a raster stack in the multiband rendering type in QGIS? I remember that it is possible to check a box in arcgis for that, so maybe i just ...
0
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0answers
19 views

QGIS editFormConfig setNotNull not working in Python

When trying to use editFormConfig(), I get setNotNull is undefined error shown below. AttributeError: 'QgsEditFormConfig' object has no attribute 'setNotNull' Below is the part of the code used....
1
vote
1answer
34 views

GADM Phillipines data won't align to WGS84

I'm currently working with several datasets in QGIS that lay 100% perfect when I match it on Google Earth using its inter-app plugin. However, when I load administrative regions from GADM, the entire ...
0
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0answers
46 views

Making NLCD92-styled land cover image from Landsat Images

I'm still fairly inexperienced with using qGIS and handling different image file types. Things I have completed: With a plugin called Semi-Automatic Classification Plugin, I was able to download ...
0
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0answers
30 views

CSV is off only on QGIS maps? [duplicate]

I'm trying to add a CSV to QGIS but it puts the coordinates off the east African coast. I've tried switching the latitude and longitude coordinates but this is not helping at all In addition, whenever ...
0
votes
2answers
29 views

How to cut (grey value) out of range colors on a raster image color ramp?

I am working on a raster file on which I applied a color ramp ("bcyr") in continuous mode and linear color interpolation to have a smooth effect. This works nicely. But if a reduce the [min max] ...
1
vote
1answer
89 views

Georeferencing a map without much info

I have part of a topographic map with contour lines and height points, but I don't have any further info about it. I know it must be in Balkan Zone 7 CRS and nothing more. How should I georeference ...
0
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0answers
27 views

How to download GeoJSON file from Overpass Turbo

I've currently set a query using Overpass Turbo, in order to download data from Openstreetmaps. When I click Export, and then save as GeoJSON, all I get is a new browser tab with the code data. How ...
1
vote
1answer
47 views

How to overwrite SHP layer

I'm modifying the Arrows plugin by Gregoire Piffault. It writes the output to a shape file, but if the shapefile already exists it fails. He tries to remove the file using QgsMapLayerRegistry.instance(...
2
votes
2answers
106 views

How to remove the overlapping part of polygons?

This might be a duplicate but after countless search I couldn't find anything that matches my needs. Sometimes a picture speaks better than words, so here is what I'd like to achieve in Qgis. I guess ...
5
votes
2answers
217 views

Problem installing new version of Qgis under windoss 10 64 bits

I installed twice Qgis 2.16 using OSGeo 4w install. First I uninstalled all the previuos version and installed 2.16. Everything worked fine but when I open Qgis I have a warning message `Couldn't ...
2
votes
2answers
54 views

Add attributes to layer

I'm trying to add a new attribute to a vector layer in my plugin. But it does not work.. Why? selectedLayerIndex = self.dlg.comboBox.currentIndex() selectedLayer = layers[selectedLayerIndex] name = "...
0
votes
0answers
12 views

How to convert time variant data within netcdf file?

I'm developing a webapplication and i want to include different global climate raster datasets with temperature and precipitation values. I have found a good temperature dataset, but unfortunately the ...
1
vote
2answers
62 views

Extract elevation data from contour lines

I am working with QGIS. I used raster-extract-contour to get contour lines from a raster image. Now I want to break up my single vector file into multiple layers based on elevation. How do I do this?
1
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0answers
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
votes
0answers
20 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 ...
1
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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
votes
1answer
90 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
votes
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
vote
0answers
22 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
42 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
votes
2answers
383 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
votes
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
votes
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
votes
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
40 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 ...
1
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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
vote
1answer
44 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 (...
0
votes
0answers
34 views

Is ST_Geom included in AWS RDS postgres 9.5?

I have a database instance on AWS RDS using postgreSQL 9.5. I am using ArcGIS desktop 10.4 and connecting to this database. The Arc docs mention needing to place the ST_Geometry.dll in the postgres ...
1
vote
0answers
32 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
votes
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.
1
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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
vote
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
vote
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
votes
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
votes
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
vote
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
31 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
vote
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
31 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
47 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 ...