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

learn more… | top users | synonyms (1)

0
votes
1answer
33 views

Choosing database for spatial and nominal data for current QGIS version? [closed]

For a nature conservationist community we are running a database (Access) in combination with ArcGIS with data about position, number and species. Our new goal is to convert the data into a (spatial) ...
1
vote
2answers
40 views

Importing OSM data into PostGIS and display into QGIS

I am new to all the GIS thing but I need to set up a full GIS infrastructure for a project. I have installed a Postgres server with PostGIS. That is on ancient hardware for now, 32bits processor with ...
4
votes
2answers
53 views

performance problem with PyQGIS: manipulating attributes

I have selected a vector layer with attributes slope and area. I want to combine all the features with slope 0 to 5, 5 to 10, ... , 85 to 90. The original features are to be discarded, and new ...
3
votes
1answer
64 views

QGIS Field Calculator functions

Using QGIS 2.12.3, within the Field Calculator "Geometry" section, there are certain functions, such as "area", that also have a corresponding term beginning with a dollar sign, i.e. "$area". I don't ...
3
votes
2answers
57 views

QGIS: Updating labels based on delimited text layer

I have a csv file that I am joining to a layer, then creating labels based on the joined layer. When creating the delimited text layer, I include the option to watch the layer. At the time of ...
4
votes
0answers
26 views

QGIS Atlas: Filter maps based on attributes (more than one)?

I have a series of maps with the same geographic boundaries but with different set of points (from the same layer). I would like to create an Atlas where the change is based on the attributes. A ...
1
vote
1answer
30 views

QGIS symbology: where are simple markers located in the system?

I would like to know, where are simple svg-markers (for example the one that is defined as "regular_star" in .qml file) are physically located in the system? I searched the system and looked inside ...
4
votes
0answers
34 views

Can I clip a geodatabase vector layer in QGIS?

I have a Vector layer loaded from a .gdb (geodatabase directory). I'm seeing my contour lines fine. I've drawn a polygon on top of the area I want to crop on a new layer. I select Geoprocessing ...
2
votes
0answers
37 views

WMS in QGIS on very high resolution monitors

I have a 2560*1440 px monitor which is bigger than what some WMSes can take. The layer doesn't load properly. Obviously this is due to QGIS requesting an image that is almost as big as the whole ...
1
vote
1answer
42 views

Addresses coming up in wrong spot

The map in which i am building will be used by an Emergency backup 911 system. I am plotting addresses from a csv file and geocoding with google. To do a test I did 100 addresses in a town I am very ...
2
votes
0answers
47 views

Why this pyqgis code cause crash dump in QGIS?

In ArcGIS there is gp.EucDirection to calculate Euclidean allocation, distance, and direction around a point, Is there equivalent function in pyqgis or gdal? I wrote a script with help of gene and ...
2
votes
1answer
38 views

Cannot edit postgis in qgis

I am currently trying to edit a layer in postgis by using qgis, but still out of luck. I don't know what I am doing wrong, and I guess it must be a very basic issue since I haven't found any question ...
2
votes
0answers
24 views

save shape file as grouped/layered vector file

I want to get the 10m natural earth countries file into a mercator projection and then into a vector file (svg, ai, etc) where for each country, its main land and any of its islands are in a single ...
0
votes
1answer
47 views

rotate point along line layer

I have two layers: point and line (postgis or shp) The line layer represent a hiking trail. The point layer the mountain passes. The points are exactly on the same position like the node of the line. ...
2
votes
0answers
16 views

QGIS Server sending UPDATE… WHERE NULL to postgis in a WFS layer

I am running a Windows Server 2012 server. PostgreSQL 9.3.5, 64-bit POSTGIS 2.1.3 QGIS Server 2.6.1-2 QGIS Desktop 2.8.3 and 2.12 I am using a Microsoft Surface Pro 4 tablet using QGIS Desktop ...
4
votes
0answers
39 views

Different styles in same label

I have a multiline label made of 3 attributes made through an expression like: "Length" || '/' || "Level" || '/' || '→ ' || "Bearing" || ' ←' I'd like to make the Length and Level lines in ...
2
votes
0answers
28 views

Shapes & categories

I am very new to this so please only smile if a dumb question. I have divided the oceans into 31 regions. Each region has various sub regions, example I have region 08; of which it is further broken ...
1
vote
1answer
52 views

projection (WGS84, UTM) issue

I have a question about projections. I have a hillshade raster with UTM 31N projection (I reprojected this from WGS 84). I also have a satellite image that I need to georeference. For georeferencing I ...
1
vote
0answers
27 views

How to create buffers having regard to topography with QGIS

I want to create buffers of 25 kilometers around points in a point-shapefile with q gis. So far so good. My problem is that I don't need an air-line distance of 25 km around the points, but a "real ...
2
votes
1answer
97 views

Huge file size after averaging two rasters

After I average two raster files (singleband gray, initial size ~700MB each) through QgsRasterCalculator() with formula "Raster1@1/2 + Raster2@1/2" the size of the resulting file is 2.9GB. Is there ...
2
votes
0answers
34 views

Setting extent with python in QGIS in new project

Situation: I am trying to write a simple python script for QGIS. The script aims to load one layer, zoom to given coordinates, and 'place a pin' there. The coordinates will change every time I run the ...
3
votes
1answer
83 views

Automating QGIS project composer printing?

I have a large project which consists of around 10x QGIS project files. Each project contains a print composer with an atlas set up to generate up to 10 maps. What is the easiest way to automate the ...
2
votes
1answer
51 views

How to display different layers with different CRS in one canvas in a standalone application?

I am a freshman of the pyqgis. Now I load the raster and vector data in the standalone application. The two data are same area, but in my canvas, they are at different places. I want to know how to ...
2
votes
2answers
47 views

Adding more than one legend in QGIS Print Composer?

I'm using QGIS 2.8.4 and I can't seem to figure out adding more than one legend to my Print Composer. Say I want a larger map and then an inset map -- showing perhaps a different classification/color ...
2
votes
1answer
56 views

Is it possible to do parallel processing in GDAL and QGIS?

It seems when processing with large raster dataset in QGIS, It causes crash dump, for example in QGIS failing to complete clip or intersect and crash dump in qgis , Is it possible to use gdal parallel ...
6
votes
1answer
72 views

Reason for error when saving shapefile in a new projection

I tried to save a WG84 shapefile as a UTM 16N projection and got the following error: "Export to vector file failed. Error: creation of layer failed (OGR error:Failed to open Shapefile `HF patients ...
2
votes
0answers
26 views

Getting started with Qt and QGIS

I would like to use GIS data as input in a C++ program, to do some work around data before to pass them to the program core, then display some maps. I would like to do that with the QGIS C++ API. I'm ...
1
vote
0answers
29 views

Problems opening ArcGIS 10.3.1 .shp files in QGIS

I'm using QGIS version 2.12.1-Lyon for Mac and trying to import a .shp file that was apparently created with ArcGIS 10.3.1. I keep receiving the "invalid data source" error message no matter how I try ...
3
votes
2answers
106 views

QGIS: How to analyze relationship between two layers of points?

I have a layer of points that are patients who were readmitted to the hospital and a layer of points of patients who were not readmitted to the hospital. I want to find geographical factors that ...
2
votes
1answer
26 views

QGIS: Distance units in CRS layer: WGS 84

First post so please bear with me. When I run a vector analysis on two shapefile layers with multiple points, I get a distance as my answer. What are the units on this distance?
2
votes
1answer
30 views

Not all KML attributes import into attribute table

I have a .KML file that has placemarks that have four main pieces of data that I want to use in QGIS. When I do 'Add Vector Layer' and select my KML file it imports all the placemarks as feature ...
1
vote
0answers
39 views

Polygons get lost when doing Join attributes by location

I am trying to do the operation "Join attributes by location" in QGIS. I have a point layer and a few polygon layers, all of them in shapefile format. I want to sum the values of the attributes of the ...
1
vote
0answers
33 views

How do I change my “no data” values to get “true” values in raster calculator in Qgis

I have two rasters and I want to subtract the values from one of the layers. The first raster is a altitude raster and the second raster is depth values for a lake. I would like to subtract the depth ...
1
vote
2answers
48 views

Update field based on spatial query (QGIS)

I was an intermediate user of MapInfo and have recently converted to QGIS. I would often use MapInfo to add a column in boundary file A saying which zone in boundary file B it is contained in. ...
3
votes
1answer
29 views

Rasterize vector file using gdal.RasterizeLayer() without losing attribute information in python

Is it possible to rasterize a vector file with gdal.RasterizeLayer(), saving attribute as Raster value ? Like gdal_rasterize can do with : gdal_rasterize -a attribute -ts rasterXsize rasterYsize -l ...
1
vote
0answers
17 views

Editing a .dgb vector file on Qgis 2.8

I have a *.dgb file on landcover (vector format). I am however battling with trying to edit this file. None of the edit tools are active. I have changed the file to not read only.
1
vote
1answer
41 views

QGIS, how to create a grid that does not exceed the extent, constrained within the extent

I have to create a grid of 15mx15m over an area much bigger, 25000mx25000m. Of course it means that the grid will never properly fit within the extent, but it will exceed a bit (25000/15=1666.6667). I ...
1
vote
1answer
25 views

QGIS - does a tool exist to calculate the (PostGIS) polygons containing a given point?

This is the converse of the analysis provided by the fTools plugin "Points in Polygon": Given a single point and a list of vector layer polygons (PostGIS in my specific case), is it possible to list ...
1
vote
1answer
20 views

QGIS Way to join based on different length keys fields?

In QGIS is there a way to join a .shp file to a table when the keys are different length (by ignoring part of one set of keys?) For example .shp file key col like this 1500000US120730002001 ...
1
vote
0answers
13 views

QGIS .shp joined to xlsx.vrt; Classify works, Rule-based does not

Very simple set up. Tiger .shp file as a layer. Has a join to an xlsx non geo attribute table as a .vrt .shp has join on MTFCC to MTFCC in xlsx.vrt. xlsx.vrt, has a string field with a brief label ...
1
vote
0answers
11 views

qgis 2.8.1 date filter gives incorrect selection results

I am running QGIS 2.8.1 on ubuntu 14.04 x64. I applied a date filter to a shapefile using the layer Properties_General "Query Builder" button. So the query was "LOCATION START DATE" >= ...
4
votes
0answers
30 views

QGIS Color text labels the same color as the feature [duplicate]

Using QGIS 2.12.1 on Ubuntu 14.04 Desktop. What I have is a layer where each feature is a different color. I also want to label each feature but I want the label colors to match the feature colors. I ...
2
votes
1answer
79 views

How to create automatic parking bays

I have to draw all the car park spaces for several streets, I am asking for some advise, how is the best way to draw all those car park spaces? and (of 5 meters) applying some restrictions (Ej. like ...
1
vote
1answer
50 views

Hide only certain borders in QGIS?

I have shapefile (the 48MB just below the table here) showing borders of different levels in administrative hierarchies (e.g. borders within communities, between communities, and between federal ...
2
votes
1answer
25 views

How to use a SLD file from the QGIS console?

How to apply a SLD file to a layer in QGIS from the QGIS console? I tried this but it didn't work: # selecting the layer layer = iface.activeLayer() # Apply SLD on the layer ...
4
votes
1answer
67 views

WMTS not loading in QGIS

I'm using QGIS 2.12 and trying to load the following WMTS layer http://geoappext.nrcan.gc.ca/arcgis/rest/services/BaseMaps/CBME_CBCE_HS_RO_3978/MapServer/WMTS/1.0.0/WMTSCapabilities.xml from ...
3
votes
2answers
70 views

Trying to use LIKE in an expression in pyQgis

I want to select elements from a layer. The field I use is a string/character field. My code is as follows: expr = QgsExpression(ur'"myField" = \'valueILookFor\'') it = ...
1
vote
0answers
22 views

Problem with OpenLayers plugin [duplicate]

I use QGIS in my daily work, but since a few months back I'm unable to do this due the OpenLayers plugin no longer being functional. When I try to load a background map nothing happen - the canvas ...
2
votes
0answers
31 views

QGIS 2.12.3 Crashes on buffering line vectors

I'm using QGIS 2.12.3 and I'm trying to create a buffer of 100 mt around a line vector using the Vector - Geoprocessing Buffer tool, but qgis crashes at every try. I've already checked that the RS of ...
2
votes
1answer
29 views

pyqgis - Editing a feature - Is it possible to set a listener?

is it possible to set a listener that is fired when a feature is edited? What I imagine is this: A geometry is edited (e.g. cut operation) then a listener is fired. This event gives me back the ...