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

learn more… | top users | synonyms (1)

0
votes
1answer
188 views

QGIS still not rendering WMS layers

Similar to Neil's question of March 8th 2013: QGIS not rendering WMS layers I can down load the BGS 1:50K bedrock and superficial deposits maps OK, but they don't render except at scales greater ...
1
vote
0answers
129 views

How to export the legend (Layers Panel) as an image in QGIS using the Python console?

I want to export the Legend (the Layers Panel) as an image using the python console.
1
vote
1answer
260 views

How to calculate highway lengths using QGIS? [closed]

I need to create a network of highways in 8 states of the USA. Eventually, I need their length, the speed and if possible average daily traffic volume, I don't know how to extract this information. ...
1
vote
2answers
103 views

How to bring all “tourism:attraction” from points table and polygon table together?

Im using OSM data as osm2pgsql-import (from extract.bbbike.org). And I want to draw all attractions ("tourism" = 'attraction'). The most of the attractions I found in the planet_osm_point table. But ...
0
votes
1answer
140 views

How to convert boundaries in image to polygons in QGIS

I have an image from a cities districts and their boundaries and I need them as polygons in QGIS. I tried "Raster -> Conversion -> Polygonize (Raster to vector)" as described here, but that ...
0
votes
1answer
427 views

Using gdal merge correctly?

Currently trying to use gdal_merge within qgis to stack three raster bands, the command it's showing is like this: gdal_merge.bat -separate -of GTiff -o out.tif "LC80190302014126LGN00_B4.TIF" ...
4
votes
2answers
416 views

How to select all files in a directory for merging in Processing?

I'm writing a generic script which involves writing shapefiles to a directory which are then merged together. After writing the files out to the Output folder, I'm trying to get the ...
0
votes
1answer
274 views

How to colour contour lines in .shp file when the lines are not meeting in QGIS?

I am doing bathymetry analysis, where I would like to color the contours one by one in the case land is rising (or sea level going down). There is a comprehensive explanation about coloring contours ...
1
vote
0answers
105 views

How to calculate the area of overlapping buffers within a single layer

I am very new to GIS, so don't know if this is EXTREMELY easy or impossible. I have GPS coordinates for stores (about 15000) for which I have created a buffer zone around each store location ...
1
vote
1answer
81 views

Is it possible to set symbol layers always on top?

Is it possible to set symbols always on top, also if the layer with the symbol is drawn under another layer? Example: My layer order is like that: Streets (top) Buildings Landuse (bottom) The ...
1
vote
0answers
72 views

Why does the “calculate” button remain gray in Group Stats Plugin?

I'm trying to use the Group Stats Plugin. I found your tutorial and I wanted to post a comment but I have seen that it is not possible then I thought to write here. Unfortunately I can not use the ...
2
votes
2answers
829 views

How to resample a raster to higher resolution in QGIS?

I'm fitting a SDM using R. A requirement is that all environmental predictor layers have the same extent, origin and resolution. I have high resolution bathymetry data (25m) that I will resample to ...
1
vote
1answer
92 views

How can I convert SRTEXT to PROJ4TEXT with QGIS

I have a SRTEXT like this: GEOGCS["My Data",DATUM["Not specified (..... I want to get PROJ4TEXT of this STREXT. Can I get it from QGIS. Because I want to insert it in Postgresql SPATIAL_REF_SYS ...
1
vote
1answer
52 views

Attribute table in map composer is limited to 99 rows. How to change it?

I am using Qgis 2.2. I am about to create a cadastral index map, which are showing the parcels in specific gridcells, also there is an attribute table connected controlled by an atlas function. So by ...
2
votes
2answers
723 views

Using ST_split to split a line feature using nearby points

I have a line shapefile and a point shapefile, and the line has just one segment and its attribute table, the point shapefile has points near the line above, not on it and the close ...
1
vote
1answer
57 views

Why are some QGIS 2.2 bar graphs not displayed?

I created a vector layer containing all European countries and some double information about them. I'd like to show this information for every object in a bar graph. My problem is that the bar graphs ...
1
vote
1answer
1k views

TIFF to MBTILES conversion on a mac

I have a large number of tiff files (map tiles) along with tab and tfw file types as part of an Ordnance Survey download. This is for an offline iOS app. I managed to get the tiffs into QGIS with ...
0
votes
2answers
318 views

Where to find Metropolitan Statistical Area (MSA) KML data? [duplicate]

Hello GIS stackexchange, GIS is not my field, so I apologize if my question is very basic. I need this data for a odd job at work. I have been unsuccessful in finding the data from Google ...
1
vote
1answer
34 views

QGIS Custom CRS has some glitches

I am georectifying scanned versions of Survey of India maps, which are in Everest spheroid and india_nepal datum. The exact parameters are: +proj=longlat +a=6377301.243 +b=6356100.2284 ...
0
votes
0answers
78 views

Converting/clipping KML to shapefile in QGIS without truncating field information (data)?

While I am clipping KML file by using polygon shapefile in QGIS, filed information (data) are truncating .Anybody can suggest a solution for this one.The same data losing issue occurring, at the time ...
0
votes
2answers
523 views

Exporting to 2D (Arcview 3.0 compatible) shapefile in QGIS?

I need to run my shapefiles through a web mapping application which is incompatible with 3D shapefiles. At present I run them through the FME Universal Translator in Mapinfo, which enables you to ...
2
votes
1answer
40 views

Update joined table fields when a MySQL database is updated

Using Qgis I joined feature tables with tables from a MySQL database. I imported the database's tables as new vector layers. Is there any way to update the joined table's fields each time the MySQL ...
1
vote
0answers
608 views

QGIS GRASS plugin missing!

I just installed QGIS version 2.2.0-Valmiera on my mac with OS X. First I installed all required frameworks. QGIS is running, but the Grass plugin is not existing. In the toolbox the grass tools are ...
1
vote
1answer
56 views

Why does Points in polygon create empty PNTCNT column from OSM points?

I tried to use the Points in polygon tool in qgis 2.2.0 and it worked fine as long as I used my own points. When I tried to 'count' the points generated from OSM layers both from dowloaded ...
4
votes
1answer
180 views

Can I use a QGIS geometry in a Python PostGIS query?

I have a "Python Init function" for the attribute form in QGIS, which is called when I add a new geometry. I can access the geometry of the newly created feature like this geom = feature.geometry() ...
1
vote
1answer
366 views

Labels appear and disappear for no apparent reason using QGIS?

I'm going through the Alaska sample data tutorial for QGIS 2.2.0. Some of the lake labels appear and disappear at different scales when zooming. At 1:314,460 Becharof is visible, but Lower Ugashik ...
0
votes
1answer
76 views

How to put marker on vector layer with lat/lon on QGIS [duplicate]

I have a vector layer, and bunch of lat/lon values. I want to put markers on the vector layer for each lat/lon pair. I have never used QGis, would you help with it. thanks.
-1
votes
1answer
311 views

Convert Road layer shapefile into a graph

I'm going to use Astar algorithm to find a path between two selected points.And I used the following code for that.Is there any way I could convert my Road Layer shapefile into a graph, which can be ...
1
vote
0answers
162 views

QGIS 2.2.0 GRASS not worked

I use QGIS 2.2.0 on Windows 8 64 bit. I try to install use Standalone installer and OSGeo4W and still get the error And then i start GRASS C:\Program Files (x86)\GRASS 6.4.2>grass64 ╬╪╚┴╩└: ...
1
vote
0answers
185 views

How to add a large inset svg or pdf in QGIS 2.3 print composer?

I have a 48x36 wall map that will include 5 large inset maps, the largest of which is almost 11x17. Due to a bug with html annotations, I need to export each inset individually then include them as ...
1
vote
1answer
360 views

QGIS Slope Classification Issues

I am very new to QGIS for the primary purpose of creating a slopes layer so we know where slopes are above 15% or 20% or whatever we finally decide. I have used our DEM to create a slope geotif and ...
1
vote
1answer
157 views

How to filter data by category, then map only maximum-value row for each?

I'm building a consolidated map of all transit systems in my area in QGIS. I have a GTFS dataset of bus lines, and it includes shapes for every trip on every route in the system (as it should), but ...
2
votes
1answer
1k views

QGIS contours smoothing and cleaning

Trying to utilize the contour extraction QGIS tool but having trouble creating smoothed contours. The smooth, generalize, and dissolve tools have not worked for me. Also the plugin for contours ...
2
votes
1answer
114 views

Is it possible to create Rule-Based Styling with $geometry intersecting a second layer?

I am trying to create a rule-based style based on geometries from another layer. I have found an example that does exactly what I want, except that it uses a geometry from WKT: intersects( ...
4
votes
4answers
331 views

How to make an editable City Map from OSM data?

I want to make a map of Cardiff, Wales, showing features useful to tourists, e.g. roads with road names, parks, museums, other POIs, etc. I want the final map to be clear to read - simple roads and ...
1
vote
1answer
117 views

shp2pgsql data appent without gid

I have a shape file, I opened it in QGIS that has columns in attribute table named CITY_NAME, POPULATION and I have a database table in Posqgresql that has columns named gid (primary key), ...
1
vote
1answer
476 views

Convert shape file to kml without losing symbols

I am using QGIS 2.2 and want to convert a shape file containing point coordinates with userdefined svg-symbols to a kml file. Everything seems to work. The orginal file is in WGS 84 / UTM zone 32N ...
3
votes
2answers
141 views

Method for automatic aggregation of polys with sparse data

I am part of a project on presenting health related data on maps. In order to maximize the analytical usefulness of the data, we wish to divide them into as small areas as possible. However, to ...
2
votes
3answers
2k views

Calculating slope in percentage with QGIS

I'm working with QGIS, v. 2.0.1. I have several soil types. They are (amongst others) described with slope indications. I already calculated the slope from the DTM in degrees, but as description of ...
2
votes
1answer
288 views

How to add an interpolation raster from the python console in QGIS?

I'm trying to add an interpolation layer based on an existing vector layer by using the Python Console (initially in the menu Raster/Interpolation), but can't find anything related in the ...
0
votes
1answer
271 views

How to open QGIS using VBA?

Using VBA, I want to open QGIS (the actual GUI) and execute a simple script through the Python console or the editor.
0
votes
2answers
727 views

How to add polygon height in QGIS or PostGIS?

Is there an easy way to set the height of polygons in QGIS or PostGIS? I am trying to visualize polygons by turning them into volumes (same shape at the base and roof, but with walls). I would then ...
1
vote
2answers
246 views

How to split a (road) buffer using the centerline?

I have a road centreline dataset which I have buffered using the road width. I used the standard QGIS buffer tool. I realise for my analysis I actually need to split the road buffer in half and ...
2
votes
1answer
715 views

How to undo misclicks while drawing a polygon?

I'm trying to draw some polygons in QGIS 2.2 and I lose it, because everytime I misclick, I don't find a way to undo that point and start drawing again. I'm sure there's a way. Does anyone know it?
1
vote
3answers
43 views

Adding combined footage to points from the beginning of a line

I'm trying to add the footage of each point from the beginning of the line to the end. There are around 4k vertexes between the two ends that I need to put the footage from the beginning of the line ...
1
vote
1answer
566 views

Reprojecting a raster DEM from meters to feet using QGIS?

Is there a tool in QGIS that does the same as reprojecting a raster DEM from meters to feet as in ArcGIS's 3D Analyst > Raster Math > Times ?
0
votes
2answers
352 views

How to make a routable graph from a Point and a Line shapefile, using Networkx?

I have one shapefile which consists of all the streets in the study area, and another shapefile which has points representing origins and destinations. I would like to know if it's possible to find ...
1
vote
0answers
15 views

QGIS DBmanager import file append not working [duplicate]

I am using QGIS and connecting to Postgresql database. I want to import shapefile data into database table via DBmanager tool. But Append data to table selection is inactive like following image. I ...
2
votes
1answer
109 views

Is there a way to clip a polygon layer according to DEM elevation?

I have a polygon layer on top of a DEM. Is there a way to clip the polygon layer according to elevation, ie the clipped result being only those areas of the polygon layer between x and y altitude? ...
0
votes
1answer
65 views

QGIS GRASS plugin: r.composite quality loss

When using the r.composite tool within the GRASS plugin in QGIS, the result raster has a cell size of 150x150 while the input rasters have a cellsize of 30x30. Can this be overcome somehow or is this ...