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

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4 views

Multiple QgsRubberBand creation and destruction?

Currently the following code-snip works great to highlight a shape based on the 'feature' and 'layer' variables: self.rubberHighlight = QgsRubberBand(self.iface.mapCanvas(),QGis.Polygon) ...
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0answers
6 views

What's the QGIS Legend Format Syntax to have thousands separated by commas?

I have numbers in the millions and would like to know what string to enter in the Legend Format box to have thousands separated by commas ex: 2,000,000
1
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1answer
20 views

How to use the field calculator between different points of the same layer?

I'm in a course learning about GIS systems, and we have recently recorded a gps track. I've exported this track as .gpx and imported the points into QGIS. Each point has a timestamp. One of the ...
1
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1answer
9 views

Detect QGIS exit in plugin

I built a plugin in QGIS and needs to stop it when user wants to exit to remove signals and close properly. How can I get an event when QGIS is exiting ?
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0answers
20 views

Is there way to define processing extent in QGIS?

Is it possible to define the extent of a processing tool, like it is in the "Environments" in ArcGIS? For example "Same as Display, or "Same as Layer..".
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3answers
87 views

How to create a compressed GeoTIFF with the 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 ...
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0answers
20 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 ...
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0answers
23 views

Deriving length values from GPX files in QGIS

I’m missing something real obvious and I apologize for revisiting a topic addressed in several Q&A’s here. I’m an experienced GIS user (not programmer) who’s new to QGIS (can’t afford Arc in ...
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0answers
11 views

Using QGIS to create a single # band raster Image [duplicate]

I recently downloaded some Landsat Images. They are in GeoTIFF format. The images are in the different bands. How can I combine them for example if band 1 is Red , band 2 is green and band 3 is blue, ...
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0answers
31 views

Adding Scale Bar to Map in QGIS 1.8? [on hold]

I'm a fairly basic qGIS user (mainly self-taught with a manual for veterinarians), and am having a bit of trouble using the composer. I am using qGIS 1.8.0 - Lisboa. I basically am plotting certain ...
1
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1answer
61 views

Can we avoid using SIP library when writing standalone QGIS python script

I wanted to write a small custom python script using QGIS functionality. So I started with the QGIS documentation on the custom application section. After having some troubles with the import ...
1
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1answer
19 views

QGIS 2.8.1 Consult a space object and to lead me to a specific folder

Folders display in QGIS clicking on an item. I desire to help me because it is very important. I need you to click on a space object redirect me to a desired folder. Mostrar Carpetas en QGIS al ...
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2answers
52 views

Creating polygons from line segments using PostgreSQL and PostGIS

Is there a PostGIS function that creates polygons from multiple line segments? I want to convert the pictured thirteen lines to four polygons. All lines belong to the table "boundary" (gid, geom). ...
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0answers
15 views

Getting unhandled exception in 'ntdll.dll' when instantiating QgsMapCanvas in debug mode

I develop a app in C++ with Qgis components with VS2010 Prof on Windows 7. Compiling a release succeeded and the app´s behaviour is as expected. Nevertheless I would like to take advantage of the ...
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1answer
16 views

Multiple ComposerMap items not rendering properly Pyqgis

I am currently trying to put together compositions using inputs from two different map canvases. One is from a canvas built and controlled via a plugin, the other is the the main QGIS canvas (accessed ...
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1answer
34 views

QGIS Numerical Vertex Edit - anyone else finding it doesn't work?

The QGIS Numerical Vertex Edit plug-in used to work fine, but stopped working for me around about QGIS 2.6. I now use QGIS 2.8.1 Windows 64 bit. The plug-in no longer seems able to see points or ...
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0answers
16 views

Progress Bar gets stuck converting Lines to Polygons using QGIS?

I'm trying to convert lines to polygon using QGIS 2.8.1. I use Vector > Geometry Tools > Polygons to Lines. I always get the progress bar stuck on 90%, it can't get to 100%. Could someone ...
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1answer
45 views

Creating polygons from from existing maps

I am newbie in GIS and have started using QGIS for my purpose. My purpose is to map all districts of Singapore and create a Shape file and get GeoJSON details for all districts. I am not able to find ...
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0answers
25 views

QGIS and Intel Tablet Processor Compatibility

Will any Windows based tablet with an intel processor be able to run QGIS, provided it meets the requirements, or is it only the Surface Pro that is capable? Looking for a cheaper solution to the pro. ...
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1answer
45 views

PyQGIS - load PostGIS layer as editable

I can load a PostGIS layer on QGIS' map canvas but "Toggle Editing" button comes "inactive". How can I load vector layer as editable? The code given below loads PostGIS layer on map canvas & ...
1
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1answer
57 views

Giving line features of same layer different colours

I have one layer and there I have different lines. Imagine these lines are pathes of persons. So image a person x and y. And I now want to differ them by just watching on the different colours of the ...
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0answers
23 views

GRASS GIS r.slope.aspect write errors

I am running into an error running r.slope.aspect I have never seen before. When I run it, I get the following output: r.in.gdal complete. Raster map <dem> created. WARNING: map [slope] - ...
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1answer
26 views

I can't add an img file to QGIS 2.8.1 on Ubuntu 15.04

When I try to add an img file to QGIS 2.8.1 with Ubuntu 15.04 I get this error message: Raster layer: /media/thomsec/D/Nu_Data/world/ocean_floor/age.3.2.img/age.3.2.img is not a supported raster data ...
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0answers
29 views

Calculating near area from road using QGIS? [on hold]

How to calculate the near area from a road with python. I am trying to build a plugin to calculate the near plot from a road and put the number 1 on it the next put the number 2 on it. I want to do ...
1
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1answer
29 views

Create a regular grid of sample points with angle and give them a value

I'm mapping able points to archaeological research. Using QGIS, I need to create a regular grid of sample points, give them a value, specifying spacing and rotation. Better if it results inside a ...
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0answers
19 views

Why are text values ending up in wingdings or something similarly useless?

I have dissolved a layer in QGIS 2.8. The resulting layer has all the column labels and text fields changed to wingdings or something similarly useless. When I look at the layer in ArcGIS, there is no ...
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0answers
17 views

Does Scimap work with QGIS?

Does anybody know if Scimap ( http://www.scimap.org.uk ) works with QGIS? I know it is supposed to operate with ArcGIS and SAGA but as I am very much a beginner with QGIS I would like to know if its ...
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0answers
44 views

How to open none .qgs files in QGIS Wien? [duplicate]

I have tried tried to open my older qgis files made on a mac on my new PC. Wien(2.8) only seems to allow .qgs files so all my folders appears empty when I access them from QGIS on the PC.
3
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1answer
40 views

Using Cassini-Soldner projection in QGIS?

I have a shapefile in a Cassini Soldner reference system centered in Monte Mario (Italian cadastre map). I want to insert these data inside QGIS in order to compare data with aerial images. When ...
1
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1answer
21 views

How to view a postgis raster query in QGIS

I have successfully loaded a large number of .asc images (>2800 200x200 tiles) into a Postgres table with PostGIS 2.1 support. The new table appears in QGIS's DB Manager and I can add the whole image ...
0
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0answers
25 views

qgis2threejs - rendered surface edges “bleed”

I am using qgis2threejs on some raster datasets representing different potentiometric surfaces of aquifers. The rendered 3D images from qgis2threejs have the edges of the surfaces "bleeding" down to ...
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0answers
21 views

Nothing in the feature box QGIS?

When I add a feature, the feature attribute box comes up but it has nothing in it...completely blank, no fields. It used to come up but stopped. I have re-installed it but the same thing occurs.
1
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1answer
26 views

Is it possible to create print templates in 2.6 and 2.8?

Is this possible? I can only find the option to 'Add items from template'. When using this option, the page setup defaults to A4 landscape and you must manually change these settings using the ...
2
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1answer
36 views

How to create a point between two other points in QGIS?

We are capturing sample points from survey maps. In between two points we have to introduce another point (as in fig), like - if the sample points are 42 and 42.5 we have to introduce another point ...
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0answers
26 views

How to extract the raster files from .prj?

I am interested in using Raster Calculator tool for which i need the desired raster files. But i came across a problem i.e. when i converted my vector files to raster and saved them they were saved ...
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0answers
21 views

Branching factor in River system?

I would like to find the branching factor for a river system. I have tried dissolving it then trying to find the branching factor but I'm not to sure how. So I have it from west to east like it ...
1
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1answer
45 views

How to get path for layers listed in a combobox?

I want to get the path of a layer in my plugin, in the console it works fine but in my plugin it gives me the error AttributeError: 'NoneType' object has no attribute 'dataProvider' def run(self): ...
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0answers
33 views

Using QGIS in medical Science? [on hold]

I was wondering if anybody would be interested in collaborating? My Idea is using QGIS to analyze and quantify Immunofluorescence raster images of cells from human serum.
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0answers
38 views

Boundless QGIS version outdated [on hold]

I recently downloaded the QGIS package from Boundless, it seems to be outdated. It is version 2.2 while we are at version 2.8.1 LTS. Does an update is planned?
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0answers
14 views

QGIS alignment is off when map is exported from Print Composer [duplicate]

I have alignment issues in QGIS when exporting my map (made using Bing). When I export it to pdf my layers show up in a different place to where I put them. It looks fine in print composer, but not on ...
0
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0answers
26 views

How to compute and label distance between points on a line?

I have a line and i want to find and label the distance between the nodes (like the cad aligned distance). v.distance outputs an empty vector file. Is there another way?
9
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4answers
1k views

How to model a graveyard - one point per deceased or one per grave? [on hold]

This is a continuation of my previous question about our project on how to economically get away with the implementaion of a graveyard in a GIS system… On the graveyard we can find Regular ...
1
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2answers
30 views

How to remove a certain number of digits from the front or end of an attribute field?

Can I use the filed calculator in QGIS somehow to remove the first 4 numbers in all attribute fields in a column? Example 16011234 -> 1234 EDIT: Silly, I can just subtract with 16000000 in this ...
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0answers
24 views

Georeference Error Messsage QGIS

I'm trying to georeference a 1922 map of Africa by Bartholomew. (found here http://www.davidrumsey.com/maps5268.html). I have it in QGIS and currently the Raster has the default CRS (WGS 84). I have ...
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0answers
19 views

How to display a picture in QGIS custom form?

I'd like to integrate an UI file as a form in QGIS 2.8. The UI file is created in QT Designer. One of the attributes in the attribute table is a filepath to an image. I'd like to display the picture ...
0
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1answer
43 views

QGIS C++ Hello World example crashing

I have written a very simple C++/Qt application using QGIS comprised of a single "main.cpp" file as below: #include <qgsapplication.h> int main(int argc, char ** argv) { QgsApplication ...
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1answer
49 views

QGIS Wien 2.8.1 RuntimeError concerning the sip module on Win 7

I am running windows 7 64bit and python 2.7.9 I just installed QGIS Wien 2.8.1 and it crashes on start up with the following code: Couldn't load PyQGIS. Python support will be disabled. Traceback ...
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0answers
29 views

Limit Extent of OpenLayers Map in QGis

I am trying to work with a OpenStreet map of Ontario, using the OpenLayers plugin. The problem is that the entire global view renders, slowing down my work. A couple of solutions come to mind: ...
0
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1answer
33 views

Merging SHP lines with attribute data combined?

I have one shapefile which contains hiking routes and another shapefile which has ski routes. Sometimes they follow the exact same path. In QGIS if the lines mentioned above are in the same SHP I ...
2
votes
0answers
46 views

Processing plugin Python error on startup of QGIS 2.8.1

I've been running QGIS with no issues for several versions now, but after I upgraded to 2.8.1 Wien I had trouble running two plugins: qgis2leaf (which I believe depends on Processing) and Processing. ...