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

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0
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1answer
48 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
1answer
24 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
43 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
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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
56 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
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0answers
30 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
98 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
38 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
87 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
52 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
60 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
75 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
28 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
32 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
110 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
28 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
37 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
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0answers
40 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
35 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 ...
2
votes
2answers
65 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
18 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
26 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
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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
12 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
80 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
52 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
26 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
74 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
71 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
34 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 ...
2
votes
1answer
43 views

Why is QgsFeatureIterator returning bad data?

This is a spin-off of another question I asked previously, but it has grown in scope and deserves its own thread. While iterating over a vector layer (shapefile) I included the following ...
1
vote
0answers
30 views

Choosing CRS to use for South Africa that will give map scale in meters in QGIS?

This has been a constant source of frustration for me. I can't seem to always get my map scale in meters in QGIS, even if I use a CRS that has map units of meters, e.g. Alberts Equal Area and others. ...
2
votes
1answer
32 views

Plotting points conditionally using cluster number in qgis

I have a set of locations such that there are partitioned into five clusters, I used the categorized property under styles to differentiate points belonging to different clusters using different ...
5
votes
1answer
49 views

Shapefile projections not matching up in QGIS?

To start off with, I'm very new to QGIS. I'm attempting to place a shapefile with locations for 3 substations on a map of Peniche, Portugal. The locations for the substations are given in latitude and ...
1
vote
1answer
20 views

QGIS - Have spreadsheet with col from 0% to 100% plus null want 100 bin gradient plus one more for null

Newbie alert. Have a spreadsheet with no geo; has a col with values in there from 0% to 100%, plus several blanks/nulls. Ideally would like a 100 step (bin) gradient fill from 0 (100% black) to 100 ...
2
votes
1answer
46 views

Adding new columns from other shapefiles - Land use density

New here but I've been following the stack exchange for a while to get many answers on my newbie journey in GIS. I'm trying to find out how to merge different point in polygon classes by column. ...
2
votes
1answer
30 views

Is it possible to change the default “symbol template” for layers added to QGIS?

Can QGIS be configured so that the fill symbols of layers added to the map automatically have a transparent border? I'm calling it a "symbol template" because I don't know what that's called in ...
1
vote
1answer
28 views

How to make colour tables in QGIS to use in multiple projects?

I would like to know how to make a colour table that can be saved and used across many projects. I am using this to colour rock types, for example: Rock one=blue Rock two= yellow Rock three= red etc. ...
1
vote
1answer
49 views

QGIS Processing Script will not Validate

I am writing a script for QGIS that will identify the perimeter of only external facing walls. The script is probably a little long to post directly into this post, but it is accessible here. The ...
2
votes
2answers
49 views

Split Vector Points/Polygons by Vector Grid and assign to relevant grid

I have 3 vector shapefiles (1: Point, 2: polygon, 3: vector grid) that I would like to combine so that the points and polygons are 'assigned' to the relevant grid cell within which they are contained, ...
1
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0answers
36 views

How to automate the QGIS Raster Interpolation Plugin using python console?

I have a rainfall data from 1961 to 2015 for each day of this years. I need to create a raster for each day with this configuration. Do you know how to automate this using this plugin and python?
4
votes
1answer
65 views

How to get r.drain to run in QGIS/GRASS?

I use the GRASS GIS extensions for QGIS (QGIS version 2.12.3 with GRASS 6.4) and I have a problem with the r.drain algorithm: I simply cannot make it work with a given starting point as a vector ...
3
votes
2answers
143 views

latitude/longitude to linestring or points

I have a gps file that I have converted to csv, I would like to convert a longitude/latitude to linestring if the next row have a diferent longitude/latitude (if the car mooved) and if not convert it ...