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

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1answer
12 views

Selective labeling with QGIS

I have a layer where shapes are defined by rules (country) and secondly by categories (a type). I then select (check box) the country to show the shapes only for that country. This works very well, ...
0
votes
1answer
7 views

In QGIS, add to existing dem tiles and expand corresponding contour coverage within a project

In my first QGIS project I have dozens of digitized layers that have spread beyond the contour and dem tile area that I started with. Please recommend how to safely expand or replace the dem and ...
0
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1answer
6 views

osgeo4w not installing processing tools in QGIS toobox.

I have uninstalled and reinstalled QGIS several times from the OSGeo4W application. I have done this with no problem on several other times, but now I cannot get the tools to load. Most of the help ...
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0answers
3 views

is the “configuration dialog” = “Processing” > “Options”

Is the the "configuration dialog" referenced to in help "Processing" > "Options" Note: The 'help' I am referring to is the online Documentation QGIS 2.2 » QGIS User Guide » QGIS processing framework ...
0
votes
1answer
16 views

How to prompt for layer selection from python console in QGIS?

During script development it's useful to use the QGIS python console to test the same script on different layers. Currently I've been hardcoding layer strings and just swapping out but it isn't ...
3
votes
1answer
58 views

Exploding features based on numerical field in QGIS?

I have a set of data as polygons, each with a Number field with value X. Is there then a way to copy this into X number of polys at the same location? (ideally points distributed across the poly but ...
6
votes
7answers
275 views

Is there a quick way to clear all attributes from a layer but leave the polygons in place?

I have a Shapefile layer in QGIS 2.6 with several polygons, each of which has data in over 100 fields. I need to create a new layer with all the same polygons, but with all their data fields blank ...
0
votes
2answers
30 views

Query ShapeFile to get informations from coordinates

I have a shapefile that represents all the Hydrological Basins in the world. You can download the file from here: ...
0
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2answers
24 views

NNJoin, MMQGIS and Nearest Neighbor QGIS failed to measure shortest distance

I have two layers, one point and one line. I need the distance to the closest line from the point layer. Not NNJoin, MMQGIS nor the distance hub in QGIS provided accurate measures. Any ideas?
0
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0answers
10 views

Defining and exporting a path from discrete points in QGIS

I'm working with elevation data (NED, SRTM, etc.) in QGIS and I'm wondering how I might be able to pick a set of points from my map and export the coordinates to something like CSV. For example, I'd ...
0
votes
1answer
13 views

QGIS Treat null as zero in raster calculator

In QGIS - I have an irregularly shaped raster - I wish to clip an irregular area out of it (call it raster A) with that area set to null. I masked the area (vector polygon) I want to remove and used ...
5
votes
2answers
739 views

Load and display a layer from SQL Server using PyQGIS

I'm having a go at using pyqgis from within the QGIS python console to load a layer from SQL Server and display it. I feel like I'm part way there but I'm having a real issue getting the layer to ...
0
votes
1answer
22 views

Install QGIS on ubuntu using the compressed format qgis-2.8.3.tar.bz2

I just cant use apt install becuase slower internet connection and size of QGIS can you show me how to do insall using qgis-2.8.3.tar.bz2 file. I have tried decompressing and use the command ...
0
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0answers
34 views

QGIS How to multiply (repeat n times) a point by field [duplicate]

I have a point layer in QGIS that has a field named "Amount" that stores an integer value for every point in the layer. I want to create N points in the exact place of the feature that has N as ...
2
votes
1answer
24 views

pass custom command line arguments?

Is there a way to start QGIS with custom command line arguments and to access those arguments at runtime in a plugin? Background: I'm trying to start QGIS using a third party application(click on a ...
0
votes
1answer
33 views

Is it possible to remove small transparent outline effects between polygons?

after using the vectorizing tool I get the following result (picture). Around the cells you can see a small "boundary". This thin line is transparent and annoying. Is it possible to remove these small ...
36
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3answers
50k views

How to add Basemaps from Google or Bing in QGIS?

Like ArcGIS Desktop has the option of using basemaps from ArcGIS online, does QGIS have any such options?
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vote
2answers
60 views

QGIS 2.10.1 on Mac/ Multiple versions on Mac

I have Version 2.8.2 running fine on a recent iMac running Yosemitee. I have tried the install of 2.10.1 from http://www.kyngchaos.com/software/qgis but it doesn't work. I would like to be able to ...
0
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0answers
33 views

Coordinate transformation fails in QGIS

I am new to qgis, so this maybe a simple problem, but I don't know how to handle it. I have two layers: One layer is based on WGS84, the other on Gauss-Krueger zone 3 (GK). How can I successful ...
0
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0answers
4 views

SegFault on create an EmptyDataSource From a typedef

I had to create a specific type of point, in order to do that I create a function that create a layer from shp file and data extract of the Code : typedef bool ( *createEmptyDataSourceProc ) ...
1
vote
0answers
86 views

Unable to stylize as pseudocolor render type on MAC OSX

In a raster layer's Style Properties, I can choose pseudocolor render type, and choose a color ramp and classify the raster. However, when I click the 'Apply' button, or click 'OK', the ...
5
votes
3answers
2k views

How does manual Label Placement in QGIS 1.9 work?

There are a bunch of questions here related to labeling in QGIS, but it's not clear which version they are referring to, and I know this is something that has changed recently. Hopefully it makes ...
1
vote
0answers
12 views

How to remove temporary layer source files in QGIS

I am new to QGIS and python. Titles says it all. I'm modifying a plugin that creates some temporary files (layers) during it's run and I need to loop it a couple times. The algorithm works fine for ...
0
votes
2answers
17 views

Avoid intersection is missing QGIS 2.10, 2.8.2

I need to digitize a lot of polygons and I want to ease my work with the 'avoid intersection' button so that the new polygons do not overlap. In the manual I found (for version 2.6) that the button is ...
2
votes
3answers
410 views

Importing SVG symbols into QGIS

I've downloaded the SVG icon pack here: https://www.mapbox.com/maki/ How do I import these symbols into QGIS? As far as I can tell I need an .XML defining each symbol. Also using the Import from ...
5
votes
2answers
703 views

Unable to zoom beyond scale of 1:2,256 in QGIS?

In QGIS, whatever might be the source, I couldn't zoom beyond the scale of 1:2256. Whether it's a raster or vector, result is the same. Does anyone know how to fix this ? Edit: Thanks to Chris. ...
1
vote
0answers
26 views

Creating new empty vector layer that has same set of atributes as another layer and then copying subset of features into it

I am new to both Python and QGIS. Here's a sample of my code: unique = layer.uniqueValues(index) attributes = layer..dataProvider().fields().toList() assistant_layer = QgsVectorLayer("Point", ...
0
votes
1answer
24 views

Explanations for attributes QGIS

I have one column in my attribute table with attributes "1", "2" or "3". 1 = normal route 2 = special route because of the event (every year) 3 = special route because of the event and construction ...
0
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0answers
20 views

QGIS Georeference [on hold]

I am trying to georeference a scanned map I was given. I load it into QGIS Georeferencer and set up some control points (10 off in this case). The image seems to transform fine and I can see the ...
0
votes
0answers
8 views

Error using gdal IDW in processing script for postgis layer

I am running QGIS 2.10.1 and I am trying to use the processing toolbox to interpolate a point layer. If I use a shape file with all the default settings it works well but if I use a point layer coming ...
1
vote
0answers
24 views

how to make rectangle selection by mouse on my map(world shape file) in qgis in python

I want to make a rectangle selection using the mouse on my map (world shape file) in qgis in python and extract the lat long of the selection area but I don't understand how to do it. and don't ...
2
votes
1answer
174 views

Python Error while installing Cartogram

I am quite new to GIS and qGIS especially. I would like to install cfarmers cartogram plugin. From what I understand, this has to be done manually - so I 've followed the instructions from ...
-3
votes
0answers
28 views

How to calculate Areas of NDVI with Qgis? [duplicate]

How to calculate the area occupied by each pixel of a raster NDVI in QGIS? Excuse me, I do not speak English. Ya calcule el NDVI de una imagen Landsat con Qgis, como calcular el área ocupada por ...
0
votes
2answers
239 views

Create DEM with 1 foot contours from lidar data with 1.4 meter resolution

I have Lidar data which contains multiple .las files for an entire quad. I have figured out which .las is the area I am looking for. I was told the data is in 1.4 meter resolution and would work to ...
3
votes
1answer
181 views

How to map flood areas from a set of points containing surface and height of water?

I am working on the damages made by the typhoon Haiyan. I use QGIS 2.0 with extensions and toolbox, and MapInfo. I have vectors, rasters of the place. I want to map the flood area along the ...
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votes
0answers
21 views

new shape file addition problem

I am using QGIS 2.8.2 version, me unable to add new shape file layer. After drawing the line when I right click the mouse the line was disappearing (fig2). The new layer being shown in layer window ...
-7
votes
1answer
62 views

Why there is no EPSG code in ArcMap? [on hold]

In Arcmap, when you right click on the layer >> go to properties >> select source tab there you see the properties of projection. I cannot understand why ESRI did not managed to add SRID EPSG in ...
0
votes
1answer
20 views

QGIS legend without print composer

I'm trying to export a series of images using the TimeManager plugin. I'd like to have a legend on each, to demonstrate why my datapoints are sized the way that they are (i.e. this circle size ...
1
vote
2answers
47 views

Google Maps Openlayer plugin not aligned with the OpenStreetMap building layer in QGIS

I am working on an OpenStreeetMap (OSM) building layer (I download the imposm geojson in city Dar Es Salaam, Tanzania from https://mapzen.com/data/metro-extracts and used the building layer) and the ...
2
votes
1answer
152 views

Maximize clusters of points from coordinate data

So I am definitely new to the GIS world, so bear with me if I don't know the best way to articulate my problem. That said, I am ready to learn, I would definitely welcome any direction that you all ...
1
vote
1answer
16 views

External Standalone QGIS Application with Default Toolbars

I want to develop a standalone application and add the default digitizing and advanced digitizing tools in QGIS as-is on my application through PyQGIS. Is it similar the way you add the navigation ...
1
vote
1answer
25 views

Loop to check multiple polygons overlap in r

I have a set of polygons (available here: http://ulozto.cz/x39ELbFt/polygons-zip) created in QGis and processed in R. I would like to know if they are overlapping or not, and if yes, where is the ...
1
vote
1answer
37 views

QGIS Spatialite Views problems

I am trying to wrap my head around spatialite views in QGIS. However there are severe limitations that make it very cumbersome: Spatialite views in QGIS do no update, if the corresponding tables in ...
0
votes
1answer
58 views

Qgis network analysis why find vertex return always -1

I'm trying to compute the shortest path between points using the QGIS networkanalysis library. But the graph.findVertex always return -1. Basically what I'm trying to do is : 1/ Given a set of ...
6
votes
1answer
219 views
+50

How can I create a form so the user has to be authenticated to access a project?

I have a login form in QGIS and when it is loaded, python gives me an error for, apparently, not recognizing the findchild part. This is due to the fact that the form isn't loaded before the script is ...
0
votes
0answers
15 views

How to set QGIS mapCanvas to exact values

My QGIS 2.8.2 standalone app's mapCanvas fills a central widget with a fixed quadratic size x=y=1000 pixels. When I set the mapCanvas extent() to an area defined quadratic as well given by a ...
2
votes
2answers
86 views

How do I make equidistant circles covering the whole globe in QGIS?

What's the simplest way to make equidistant circles in PostGIS/QGIS? (my software versions are Postgres 9.3, PostGIS is 2.1, QGIS 2.10) I tried this in PostGIS, but the circles that come near or ...
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vote
2answers
43 views

How to get PostGIS DB name from QGIS layer?

I'm writing a custom Processing script that needs to know which database connection a vector layer resides in. I can't find anywhere in the API a function to return this information from a layer. So I ...
0
votes
0answers
11 views

Merge raster layers error

Is there an issue with the SAGA-tool "Mosaicking rasters"? I tried it with different rasters. In Sage itself it works fine. Algorithmus Mosaick raster layers startet... io_gdal 0 -TRANSFORM ...
0
votes
2answers
27 views

Map with just City/Country/River/etc names.

I am looking for a plug in or a map, that only has the names of the countries and cities and other urban and/or geographical features. Does anyone have or know of such a map/plugin. I'v e been ...