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

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0answers
89 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 ...
0
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2answers
603 views

How to create/obtain district data for Singapore? [closed]

I am newbie in GIS and have started using QGIS. I am hoping to map all districts of Singapore and create a Shapefile and get GeoJSON details for all districts. I am not able to find that currently. ...
1
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0answers
74 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. ...
2
votes
3answers
576 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
97 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
82 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] - ...
1
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1answer
85 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 ...
2
votes
1answer
336 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
38 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 ...
1
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1answer
25 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
45 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
527 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
463 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 ...
1
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0answers
28 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
60 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
votes
3answers
103 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 ...
0
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0answers
52 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 ...
0
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0answers
24 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 ...
2
votes
2answers
485 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
42 views

Using QGIS in medical Science? [closed]

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.
1
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0answers
59 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?
11
votes
4answers
1k views

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

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 ...
3
votes
2answers
224 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 ...
0
votes
0answers
81 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 ...
3
votes
2answers
746 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
173 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 ...
1
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1answer
345 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
179 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
68 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 ...
3
votes
1answer
514 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. ...
2
votes
0answers
114 views

Why is SAGA kriging slower in QGIS than in SAGA itself?

I'm using QGIS for a while. In my opinion the SAGA kriging tool (processing toolbox) is very slow. Is that an QGIS issue? I tried to interpolate a point layer with 300.000 points (I know it is big) ...
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0answers
28 views

install python packages for qgis? [duplicate]

I need the twisted framework (Python) for a qgis plugin on Windows 7. I installed it with the pip installer. When I want to start the plugin it doesn't find twisted. When I start a python interpreter ...
0
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1answer
151 views

Merge touching polygons with keeping their attributes

I've got a layer of polygons Although they all in the same layer, each polygon own some unique data like the date of this polygon and an amount it possess (a number). I want to join/merge all the ...
1
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0answers
72 views

Incomplete results from an intersection

I am trying to map the density of buildings in flood-prone areas. In order to do that, I created a grid of equal-sized squares. I want to intersect the layer of buildings with the grid so I can ...
1
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1answer
27 views

Digitizing 2-node lines?

I tried digitizing in to a new sqlite line layer with autoincrement id ticked..... I want to create a 2-node line, but there seems to be a minimum limit of 3 nodes. Is this correct or am I doing ...
1
vote
1answer
135 views

How to remove “ERROR 1” messages from a standalone QGIS script?

I am running a standalone script for QGIS which creates a high resolution grid and clips shapefiles onto it. Works perfect if the cell width and height have a high values (in my case, >200m for both). ...
3
votes
1answer
216 views

How to offset polyline geometries (not symbology) using QGIS?

I have a polyline layer which has a road network digitized, up the center, in both directions however the polyline are sat "one on top of the other". I can display the lines separately by ...
2
votes
1answer
144 views

Automatically adding Z-values from a DEM to an already created polygon

We have excavated a very large 5.000 year old fish fence, which was documented by photogrammetry, and is now being digitized. I started digitizing the orthophoto in QGIS and everything is cool. Now ...
3
votes
1answer
152 views

Change layer datasource in qgis project with python

I have different qgis project with some layer and their datasource like ../my_path/my_file.shp. I need to insert this shp file to a remote db. For do it i use shapefile from PGeo module and it's work ...
3
votes
1answer
221 views

How to create a virtual field in QGIS by Python Console?

Is there any example about how to create a virtual field and subsequently change the attribute of a non-virtual field without wiping out the virtual field? Both are required to be done in the Python ...
1
vote
2answers
520 views

Generate PNG/JPG maps from multiple ASCI/GeoTIFF in Python/GDAL

I need to generate maps (saved in PNG, JPG or PDF) from raster files (for each file - one map) which meets following criteria; * each map has exactly the same color pallette, so that it will be easy ...
1
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0answers
101 views

Considering “holes” in Voronoi polygon creation in QGIS?

I am trying to create voronoi polygons in QGIS that would consider "holes" in the general domain. An example would be: I actually created the Voronois in this image using QGIS through the GRASS ...
2
votes
1answer
142 views

QGIS plugin problem, can't reach objects in a Qt-based Stacked Widget

I am creating a plugin for QGIS but am having trouble with the Qt components. I have used Plugin Builder and Qt designer to create all necessary files for the plugin. I want to use a QStackedWidget ...
2
votes
1answer
235 views

merge two DEMs of different resolutions? [duplicate]

I have two DEMs, the first one is in 30 meters of résolution and the second: 5 meters, and will like if there is a possibility of merging them to extend the area where I do my research?
0
votes
2answers
493 views

Points within polygon in QGIS [duplicate]

I have a shapefile with polygons. And I have a csv file with points. Now I want to know for each point in which polygon it is situated. Every polygon has a number, so I want to create a file where you ...
2
votes
0answers
35 views

Error using grass script v.lidar.edgedetection

I'm in trouble with the grass script v.lidar.edgedetection. When I try to filter an xyz format dsm the script starts but at the end of it an error message appears (see attached image). Somebody ...
1
vote
1answer
164 views

How do I create a spatial filter on a layer?

I have a layer that draws points in a PostgreSQL (PostGIS) database. The problem is, all points in the table are being drawn. I want to limit the points drawn to a spatial query. How do I limit the ...
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0answers
26 views

Track administrative changes with QGIS

I use QGIS. I have two shape files with the administrative boundaries in two differnet years. These boundaries have changed: some wards (smallest administrative area) remain the same, some are newly ...
4
votes
2answers
997 views

How to load a raster layer using PyQGIS?

I need to load a raster file from the provided file path. I wish to use it further in the Raster Calculator. I wrote a function which converts string (I assume it is a file path) to a raster object. ...
1
vote
1answer
133 views

QGIS processing script: Move points by specified distance and add segment

I try to move points (they come as WGS84, but I'm not sure if it works with unprojected CRS) by a specified distance and connect original and new point with a line segment with the below script, but ...