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

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2
votes
1answer
777 views

Could not commit changes to layer X

I am editing a layer's (Z) attribute table. I made some columns, used the field calculator to fill them up, made some more, went back and deleted some and then tried to save the edits and got the ...
2
votes
1answer
222 views

How to avoid colliding parallel lines in QGIS Composer

I am preparing a map which is concerned with showing two line features and there relative location to each other. The line features are 20 m apart and at a scale of 1:50 000 or bigger on A3 I want to ...
2
votes
2answers
930 views

How to install DTclassifier for QGIS?

I want to install a dt-classifier plugin I have downloaded from a web page (http://gis-lab.info/qa/dtclassifier-eng.html). I unzipped it to the qgis plugin directory but it won`t show up in my plugin ...
2
votes
1answer
216 views

QGIS Console error Libgrass

Just installed QGIS 1.8. on Mac OSX Installed GSL Install GDAL 1.9 Complete Installed QGIS keep getting this console error message in QGIS. Failed to load ...
2
votes
2answers
187 views

“show only visible features” doesn't seem to work

I'm trying (unsuccesfully) to place the attribute table next to a map containing the same in print composer. Let's say for example my map in the primary window contains 6 districts and my map in the ...
2
votes
1answer
1k views

Where can I find QGIS Cartogram plug-in?

Can anyone point me in the right direction of the cartogram plugin please? I've had a look on the net but can't find what I'm looking for. Thanks
2
votes
1answer
1k views

Extracting all intersections from polyline shapefile using QGIS?

I would like to extract all the intersections from a polyline shapefile and print their addresses as text using QGIS. Is there a straightforward way to do this? My polyline has address ...
2
votes
2answers
861 views

Selecting Part of a Polygon

I have a dataset, in shapefile format, for agricultural land grades in England. It is divided into 7 categories in its attribute table. As the file is a large file and I only want a small section I ...
2
votes
1answer
483 views

How to add EPSG:5235 to QGIS?

First of all I should say I am new to EPSG and QGIS world.Then I want to Georeferced Raster image to EPSG:5235 in QGIS. But in Qgis I can't found above EPSG. How I add this EPSG to Qgis ? Pls help ...
2
votes
3answers
952 views

Communication Between Browser and QGIS Server/QGIS API

Suppose I have QGIS server up and running with some vector data. Now a user accesses this data from a webpage. Would it be possible in some ways for the user to send a request to the QGIS Server and ...
2
votes
1answer
526 views

QGIS apply style to shapefile

I'd like to create a Categorized style in QGIS, classify with it data in a shapefile and then save the shapefile with the new categorized style. Is it possible?
2
votes
1answer
343 views

Can't load PYQGIS

I get this error; any comments Couldn't load PyQGIS. Python support will be disabled. Traceback (most recent call last): File "", line 1, in ImportError: ...
2
votes
1answer
151 views

Reproject an aerial layer in QGIS and then open with ArcEngine?

I have an Aerial layer (.SID file) which I would like to re-project in QGIS, then I would like to open it in ArcEngine. I've figured out how to do this with vector layers in GGIS, its just a right ...
2
votes
1answer
200 views

Sandbars feature extraction from satellite image

I want to know if we can analyse the permanancy of sandbars from a satellite image? Whether the formation of the sandbar is permanent or temporary.
2
votes
1answer
540 views

How to create a button with QGIS

Comment créer un bouton avec QGIS? Bonjour, Je suis nouveau sur le site et je suis francophone, je cherche à crée un bouton avec QGIS mais je n'est pas arrivé à faire ce petit exercice s'il vous ...
2
votes
2answers
866 views

How to transpose the lat/lon coordinates of a shapefile?

I need X to be Y and Y to be X (switching lat/long) within the polygon shapefile. If it were a point shapefile I know I could simply reverse the lat/long or x/y parameter and import from a table. I'm ...
2
votes
1answer
202 views

How to move the last vertex till the last angle is squared?

I have problem using Orthogonal Digitizing button from CAD Tools plugin menu. It moves the first point of the polygon by holding ctrl key pressed and pressing right mouse button till the last angle is ...
2
votes
1answer
998 views

Adding or removing values in style tab (layer properties) of QGIS?

I'm new to QGIS and have recently been testing the software as my org plan to migrate from ArcGIS to QGIS in the near future. I often use the 'Add values', 'Remove values' and the group values ...
2
votes
1answer
801 views

How to convert decimal point to comma in QGIS?

I am working with data in Colombia where decimal points are written as commas. I would love to create a new column in QGIS that would convert all decimal points (periods) to commas for the purpose of ...
2
votes
2answers
712 views

How do I batch export maps for sub regions of a dataset with qgis?

I have a national level dataset consisting of polygons, polylines, points and rasters. I would like to export a map for every sub region (border defined by a polygon shapefile). Is there a simple way ...
2
votes
2answers
764 views

How do I create a negative to positive value raster with neutral 0?

I have a raster layer with a band with values from -137 to 9229. I want to create a color scheme showing how far from 0 the positive numbers are in one color, and how far from zero the negative ...
2
votes
1answer
1k views

How do I automatically fill a table column?

I would like to solve basic problem. I need to automatically fill the table. How is in Qgis possible to fill it like : if column SPECIES contain string DOG -> write to column CODE integer 1? Thanks ...
2
votes
1answer
1k views

How to add USGS DRG WMS to QGIS?

Is there a WMS server, which I can be added to QGIS, that displays USGS DRGs? If so please explain how? Thanks
2
votes
2answers
1k views

How to control line width in legend in QGIS?

I have a map in which I am defining the sizes of various features in map units. When I come to generate a pdf of the map, using the Print Composer, the map itself is fine, but when I include a legend ...
2
votes
1answer
710 views

How do I subdivide and edit polygons preserving topology?

I'm using QGIS. I have a layer made up of many adjacent polygons - let's call them "countries". I currently use the Atlas plugin to export each "country" polygon to a .png file. I want to further ...
2
votes
2answers
1k views

How to set up a plugin repository for QGIS?

I am working with python plugins for QGIS.I developed my plugin and created .zip file including my .ui,.py and resources files.In order to incooperate this plugin into QGIS i created .xml file ...
2
votes
1answer
481 views

A software architecture for viewing/editing roads and routes

I have a routing software module which uses PostGIS/pgRouting to calculate routes. The road network is generated from an .osm file with osm2pgrouting tool. I need to enhance the functionality of the ...
2
votes
3answers
691 views

How to align TIF and GPX layers in QGIS?

My initial layer is an OS tif file, with its associated tfw. I can zoom into the area I want, no problem. The CRS is OS 1936 (and that's the project CRS as well). I download a 'track' layer from an ...
2
votes
1answer
33 views

Why do labels in exports using HERE tiles appear tiny?

I am trying to export images from the QGIS print composer, the exported image has a basemap that is loaded from an XML file following this questions method. The export doesn't look at all like the ...
2
votes
1answer
39 views

How can I add a second Toolbar Button and Dialog to a QGIS plugin built with Plugin Builder?

I want to create a toolbar with 2 buttons, each button opening a different form. The steps I followed are: Created a plugin using Plugin builder Created a toolbar with 2 buttons by doing the ...
2
votes
1answer
34 views

QGIS Python variable not updating after new features are inserted

I have the following script that sets the a feature id automatically after a new feature is digitized. I added the function inside the project's Macro section inside openProject() function: The ...
2
votes
2answers
68 views

Slope Analysis in QGIS

I am New to QGIS, I have the Contour Information in the form of Line Features, How can I do a Slope Analysis. Is it Possbile at all ? For Reference I am attaching the Image. the lines in the ...
2
votes
1answer
42 views

How to render mixed geometry from one table?

I have a table in postgresql with mixed geometry, but it is not accessible in QGIS. I am running QGIS version 2.8.2. Is there any plugin to install for QGIS to render multiple geometry?
2
votes
1answer
62 views

“unexpected indent” in the script

I'm using a QGIS 2.8 in windows 10. I have 2 scripts that are working separately but when I write both in just one script, it doesn't work. The 1st script is to load one raster to QGIs with a defined ...
2
votes
1answer
56 views

Displaying data from a partitioned PostgreSQL / PostGIS table is unacceptably slow in QGIS

I have two very similar datasets of 27 million polygons stored in PostgreSQL / PostGIS. One is loaded as a single table, with spatial indexes and regular indexes on key fields. The other is ...
2
votes
1answer
28 views

How to set zero value of reflectance number of land using QGIS?

I try to get SST (Sea Surface Temperature) data from Landsat image using QGIS, but I don't know how to set zero value of reflectance in land area using QGIS. Does anyone know of any method to set ...
2
votes
1answer
32 views

Line density map in QGIS

I would like create something like that in QGIS: http://2.bp.blogspot.com/--EFSaghZ92s/VqQXXIoE4AI/AAAAAAAABKw/KGkoB8zZ6K8/s640/scs2%2Bmap.jpg I have a huge amount of points and I can import in QGIS ...
2
votes
1answer
36 views

Converting NAD 83 State Plane Maryland Feet Coordinates from lat/long and vice versa using QGIS?

I need to convert a list of lat/lon points (in.csv file) into NAD 83 State Plane Maryland Feet and vice versa. I know it can be done using ArcGIS, but I only have QGIS. I am also quite new to ...
2
votes
1answer
48 views

Why is my attributes table greyed out for raster layers?

I am trying to view attribute data for a SRTM geotiff but for some reason I cant view the data.
2
votes
1answer
30 views

How to connect QgsMapLayerComboBox to QgsDataDefinedButton

in Qt Designer there is the possibility to use directly QGIS custom widgets. In the UI I added a QgsMapLayerComboBox (to get the layers added in the legend) and a QgsDataDefinedButton. What I would ...
2
votes
1answer
38 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
43 views

QGIS: How to modify the appearence of selected attributes [duplicate]

I am using QGIS version 2.14.1 (Essen). When I open the attributes table of a layer, I select some data which is then highlighted in yellow on the map. I was wondering if it is possible to change the ...
2
votes
1answer
70 views

Styling a heat map based on point attribute, not density

I have a point dataset generated from getting the centroid points from a fishnet/polygon grid. I combined these points using a spatial join to give them an attribute of 'pressure' which is an integer ...
2
votes
1answer
76 views

Calculating total area overlapping specific raster DEM color interval whose boundaries are confined by another vector?

I know this sounds quite difficult, but maybe it isn't for you or at least it shouldn't if I explain it correctly. (I'm using QGIS 2.14) I'd like to know to calculate total area overlapping a ...
2
votes
1answer
60 views

Why do quickmapservices basemap labels shrink when printed?

I am using QGIS with quickmapservices for my basemaps. In the composer the image looks good, with labels appropriately sized. When I go to print the PDF however, the scales on everything is much ...
2
votes
1answer
13 views

Quartiles from Raster Layer band

I'm building a plugin from QGIS, and I need to extract the values from the quartiles from a band in a raster layer. Does anyone knows how it is done?
2
votes
1answer
53 views

Coordinates calculation using QGIS

I am quite new to GIS software. I use QGIS. I have a question that might be trivial. I would like to derive the coordinates (Y and X) for an area. Just to make an example: I have two regions A and B. ...
2
votes
1answer
28 views

Qgis - How to count text values

My issue is to count text values from vector layer. I got a layer with streets for one of administrative region and it's names in column. It looks like this Id Street_name XYZ XYZ ABC XYZ . . . ...
2
votes
1answer
28 views

Corners of GeoTiff's not lining up after doing gdalwarp EPSG:3006 -> EPSG:4326

I have some GeoTiff's that are in EPSG:3006 (SWEREF99 TM) atm, and I'm trying to convert them to EPSG:4326 (WGS84) because some other software needs it in this projection. But after doing the ...
2
votes
2answers
98 views

Is it possible to restore lost PRJ-Files?

Currently I am working on a project with QGIS (2.14.1). Therefore I need to add old (but important) shapes that were drawn by a colleague. Somehow most of the .prj-files are missing - I don't know ...