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

learn more… | top users | synonyms

3
votes
1answer
31 views

Performing least cost path analysis on QGIS using permeability scores for 60 points in network?

I have a map that is made up of polygons that apparently cover the whole area without leaving gaps, each representing a field, a wood, a road, a house etc. Each polygon has a score in the attributes ...
4
votes
3answers
73 views

Issues in Intersecting Voronoi Polygons With Other Boundary Shapes (QGIS)

I'm having problems in intersecting Voronoi polygons with another shape. As the image shows, I want to clip the Voronoi layer at the red costal perimeter of the UK so that the additional surface area ...
2
votes
1answer
37 views

Installing qgis-ltr or qgis-ltr-full with OSGeo4W or both?

I need some help with the installation of QGIS using OSGeo4W. I am using windows 7 and I want to install a 64 bit ltr release with all relevant dependencies and plugins. I choose to install qgis with ...
2
votes
1answer
41 views

How to get mean coordinates of features from a point layer?

I have a vector layer containing several points and I would like to generate the mean coordinates of these points, using QGIS only if possible. I'm looking for something similar to centroids, but for ...
2
votes
2answers
25 views

Creating a palette for categorized data displays

I regularly categorize data as follows: Prehistoric = blue Roman = red Anglo-saxon = green Medieval = yellow Post-medieval = brown Modern = grey Undated = white Is there any way to save this palette ...
3
votes
1answer
41 views

Accessing Command line options passed to QGIS exe

I am using QGIS 2.8, I am passing the raster image along with the qgis-bin.exe from the command prompt. Is there a way to access the name of the raster being passed along the exe in my plugin?
4
votes
0answers
61 views

Connect data from two different layers

I'm trying to connect data from two different layers to combine them in one new layer and continue working with them. Let me explain that a bit more detailed: The first layer contains data (and ...
1
vote
1answer
25 views

QGIS interactive gradient editor - already available?

i have found several links on the "new interactive gradient editor" - which seems pretty interesting and comfortable !!! the features shown in a youtube video are promising, but i didn't find any ...
2
votes
1answer
29 views

QGIS 2:14 - Border show-through on small Simple Markers

On small Simple Markers, 2.20000 mm or less, there is border show-through which I have been unable to eliminate with no pen or transparent border style. This is shown in the group of large and small ...
4
votes
1answer
63 views

QGIS: Batch export multiple layers to DXF

I have only had limited experience with QGIS. What i have: I currently have many different layers (water mains, sewer mains, drainage etc.). These layers are TAB files with attributed data. What i ...
1
vote
0answers
32 views

QGIS georeferenced image does not apear in the map area

I'm having issues with some georeferenced images in QGIS 2.10.1-Pisa. I generally georeference PDF's of new land subdivisions over aerial photos to get the layout of the new subdivision, generally ...
3
votes
0answers
37 views

QGIS 2.14: Missing list of algs in modeler (processing plugin)

I changed my QGIS-version from 2.8 to 2.14. I am very happy that v.net algs (grass7) are available now as part of the processing plugin. But now there is no list of algs inside the modeler - so no ...
1
vote
1answer
38 views

QGIS Lat/Long Postcodes Coordinates Being Placed Out At Sea?

I've read plenty of posts on this site regarding coordinate systems but none of them have helped solve this issue. I'm using Ordinance Survey Lat/Long coordinates for postcodes but a small number are ...
2
votes
2answers
60 views

postgis table - shapefile - mapinfo file [closed]

I have a .tab file with a ridiculous amount of columns (96). One of my colleagues at my new job wanted to update them manually one by one. I told him I could do that in an easier way using PostGIS. So ...
4
votes
0answers
102 views

I can't create/save changes in shape files on QGIS

I can't create or edit shapes in QGIS, the files are created on my system but cannot "fill" it with the features. I'm using QGIS 2.14.2 64bit Windows 7 This is the error i get when trying to save a ...
3
votes
1answer
46 views

Basic attribute table setup QGIS

I made several point shapefile layers. The properties only differ in their assigned colours. Each attrubute table consists of a single field "id" and each record is null. I now wish to assign a name ...
3
votes
1answer
55 views

How to Change the buffer distance from degrees to meters in QGIS 2.14 Essen?

I am new to QGIS and the whole field of GIS in general. My project and all its layers are set to the CRS of EPSG:26913, NAD83/UTM zone 13N. I am trying to use the geoprocessing tool Buffer(s) on a ...
5
votes
2answers
92 views

Subscript labels in QGIS legends

Is it possible to include subscript and superscript text in the title of a legend item in QGIS ? I have tried using <sub>some text</sub> but this just appears in the title with no change ...
3
votes
1answer
54 views

How to programmatically execute an overpass query?

I am working in QGIS using a gejson obtained from an overpass turbo query. After having defined some layer configurations and operations, I would like to update the geojson file with more up-to-date ...
3
votes
1answer
33 views

unable to render/view a postgis raster in qgis 2.14.1

I have successfully added a raster to postgis using the following: raster2pgsql -s 4326 -I -C -M 00N_030E.tif -F -t 250x250 -a test.00N_030E | psql -U postgres -d raster -h localhost -p 5432 I ...
2
votes
0answers
37 views

QGIS graphical modeler calculator

My question is about the calculator in the QGIS graphical modeler. I explain my problem issue first: I want to build a modeler that creates buffers around layers and makes a selection on a second ...
1
vote
0answers
18 views

Group location points that have a cumulative value 2000

I have a set of 400 locations (points) joined to a table having population attributes. I want to form groups of nearby locations such that the cumulative population is 2000, group can have maximum 15 ...
2
votes
1answer
35 views

How do I make a single polygon in a multi-polygon feature into a new feature?

I don't want to delete the polygon, but instead make it a new feature. There are over 100 polygons in the original feature, so 'split feature(s) parts' is not an option. None of the editing tools ...
3
votes
3answers
117 views

Statistics on classified raster overlaid with a polygon vector

I have a classified raster file and a polygon vector file. I need to overlay polygon and find out area occupied under each classification in each polygon. I am not familiar with R. Can you please ...
3
votes
2answers
41 views

How to use data from field papers to QGIS

I work on Field Papers and I need to get the information from the QR Scan code on the field papers on to QGIS. Can you please share how it can be done.
3
votes
1answer
45 views

Converting a NAD27 Lambert Conformal Conic custom projection to WGS84 using QGIS

I am trying to convert some points from NAD27 Lambert Conformal Conic (custom projection) to WGS84 using QGIS 2.8.9. I am using the datum transformation parameters for El Salvador published here: ...
1
vote
1answer
55 views

Positive Topographic Openness - do any FOSS tools (other than SAGA) provide this?

I'm looking for a FOSS GIS tool to provide Positive Topographic Openness on 32-bit Ubuntu. (which rules out ArcGIS) Normally I use SAGA GIS for this, but my Ubuntu setup is a bit messed-up after a ...
1
vote
0answers
31 views

$length calculation anomaly

A polyline layer's (green) length is being calculated via $length. Result: ~100 meters (EPSG 31466). A buffer of 5meters is created and via Voronoi Polygons (and several other steps) a centerline ...
2
votes
1answer
23 views

Get Altitude for Multiple Objects

I use QGIS and I has two layers: one with point objects (more than 1000) and one with surface (it is a version of DCW). I want compute altitude of all points. Basically, I want to get an array where ...
1
vote
1answer
19 views

Display card problem in the browser [closed]

I'm having a trouble with the extent. I don't know how to get them in QGIS and I need to display a map with two layers in a website. For this I used OpenLayers and MapServer as WMS server to serve my ...
1
vote
1answer
34 views

QGIS - Show count of same attribute in feature (on visible map or by same field)

In QGIS 2.14 I have a feature with two fields; Element Type (TF1, TF2, TF3, TF4) and Trail Nº (1, 2, 3, 4, 5, 6) Each Trail has multiple Elements. I.E. Trail 1 may have 6* TF1 and 2* TF2, while ...
4
votes
1answer
49 views

Make field in QGIS unvisible

I want to use some fields in qgis form but to make it unvisible in table. Is there any way to do it? Now if I make the field property unvisible - I can't use it in the form. I'll be glad to see any ...
3
votes
2answers
35 views

broken plugins with QGIS install

I have been struggling with this for a bit. I recently upgraded my qgis to 2.8.9, and now am having issues with the ftools plugin as well as the processing plugin. When I start qgis, I get this error: ...
6
votes
2answers
88 views

How to calculate the difference between two rasters in QGIS?

I have two similar rasters of the Mount Vesuvius and surroundings: one spans 20 kilometers, and the other one 50 kilometers. The two rasters are overlapping: What I would like to do is to create a ...
3
votes
2answers
70 views

How georeference a dxf file in QGIS 2.14?

In Illustrator I exported a PDF as dxf and inserted it in QGIS as Vector and obtained 2 layers as points and lines but it is misaligned and in a unknown location. I know georefecence a raster file, ...
0
votes
2answers
41 views

Digitizing Tools error in QGIS

I receive this message: Digitizing Tools: Amend Line is disabled because layer CRS and project CRS do not match. If I set the CRS of the layer the same as the project CRS (W84 Pseudo Mercator) is ...
3
votes
2answers
42 views

Search for textbits in QGIS

Is there a way to search for only parts of text in QGIS. Imagine I have a field in my attributetable called myField and I have several entries there, something like This is awesome Even more awesome ...
1
vote
0answers
29 views

Generate more nodes for routing

The following picture shows my routing database all set for querying loaded to QGIS. Red line is the road I want to select route from, yellow points are the vertices generated after running ...
6
votes
1answer
150 views

How to make a automatic updated date and time field in QGIS 2.14?

I want to make a date and time upadated field as I edit an attribute field in this format yyyy-mm-dd 00:00:00 (= 2016-05-08 11:04:00) - my local date/time. The data is in a QGIS 2.14 shapfile and ...
3
votes
1answer
37 views

incorrect skewed re-projected Grid lines in TileMill

I am working on a project in TileMill for the first time. I am trying to overlay a Graticule of the British national square grid. I generated a series of LineString for the grid into PostGIS, which ...
1
vote
0answers
22 views

QGIS - Split a line having attributes with UNIQUE constraint

I am using QGIS with a PostgreSQL/PostGIS database, where the lines table (named 'segments'), besides the integer serial primary key, has a UUID column having a UNIQUE constraint. Trying to split a ...
3
votes
0answers
25 views

GRASS7 r.water.outlet doesn't run correctly in QGIS 2.14.2

I am a new user of GIS software and I am currently facing an issue with the GRASS7 tool `r.water.outlet. I am a beginner with both Linux and GIS. I am using Ubuntu 14.04 with QGIS 2.14.2 and GRASS ...
1
vote
1answer
44 views

QGIS processing framework Python loading shapefile

I would like to write a Python script in the QGIS processing framework allowing the download of files from specific addresses. Instead of starting my script with: vectorLyr = vector I would like to ...
3
votes
1answer
60 views

Are calculated fields available in any database that Qgis can use

I'm trying to find a data storage method that can handle up-datable calculated fields (such as population density=population/area). I want to be able to alter the population as the data changes (like ...
1
vote
3answers
49 views

How do I separate .txt data into multiple columns when exporting to .CSV?

I have .txt data that is described as Lat Lon Elevation (meters) and when I export to .CSV in Excel it puts all data into 1 column. So when I import the data into QGIS it all dumps into 1 column, and ...
3
votes
0answers
53 views

Render Vector & Save as Raster

I am working with ENC files from noaa, specifically S57 format or ".000" to be as specific as possible. I am trying to render a layer or even the entire thing in a window but have had no luck. ...
1
vote
0answers
14 views

How to get the name of the layer on a map composer with a single layer?

I tried layer_property( 'layer', 'title') I would like to return the current layer from the map instead of 'layer'. (or list of the layers on the map?) Doesn't seems to works with layer_id or ...
0
votes
0answers
25 views

Activating LAStools - 'wrong value for parameter “Msys folder”' [duplicate]

Whenever I try to activate LAStools, I get the following error, despite setting the path as /Users/grant/LAStools/ - which is its actual location: Wrong value for parameter "Msys folder": ...
1
vote
0answers
37 views

Converting Shapefiles

Can anybody help me on how to convert shape files into .asc files? I want to convert layers from shape files into this format but I don't know how to go about it in qgis.
3
votes
1answer
59 views

How to convert from a local coordinate system to UTM (and vice versa) using mathematical expression

I have two coordinate systems- UTM Zone 23S and a local one with the following conversion from UTM to Local: EASTING: SQRT( (UTM_EAST-296787.355)^2 +UTM_NORTH-8095123.271)^2) ...