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

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2
votes
2answers
79 views

Add a serial id column inside a view

Is it possible to create a new id serial column inside a view? I need it to be able to add my view in postgis I have made a full outer join on two tables I need a unique PK to load the view in ...
1
vote
1answer
31 views

Initalize plugin with current working directory?

Upon starting Qgis, a (currently under construction) plugin needs a means of checking the current project/legend/registry. This checksum would ideally occur upon startup automatically. As the plugin ...
2
votes
1answer
44 views

Error with adding map layer to QGIS?

I am working on a project on QGIS were a i have 50 geographical point i would like to put in map. The reference system is the UTM Zone 36S. I have successfully imported the coordinates but after i ...
0
votes
0answers
29 views

How to query a WMTS layer with a point layer in QGIS?

With the "identify" tool it is possible to query WMTS layers. Then, you can copy the acquired attributes and afterwards the clicked coordinates, then create a CSV file with attributes/coordinates. Is ...
2
votes
2answers
104 views

Batch add column to layers and add layer prefix in PyQGIS

I have a number of layers each with a prefix like A_ B_ and so forth. I'd like to: Add a column (text) called DENSITY to each shp Add the prefix letter from the layer name to each row in the ...
0
votes
0answers
26 views

Can I use custom icon in QGIS?

Some custom icons created in AutoCAD maps turns into dots on QGIS. Can I use a custom icon On the QGIS or a custom icon in AutoCAD can be displayed correctly on QGIS?
1
vote
0answers
28 views

Systematic inaccuracy in QGIS shape area

I’m trying to find out why I get different area figure in QGIS than in AutoCAD when I’m using the same shape file? What I did is I drew a shape in AutoCAD, imported it in QGIS and used the field ...
3
votes
1answer
76 views

Unsupervised classification in QGIS

I was trying to learn unsupervised classification in QGIS 2.6 following the tutorial video: https://www.youtube.com/watch?v=mI80eENtWSE When trying myself, clicked Run during the process it shows the ...
1
vote
0answers
32 views

Add vector tile sources to QGIS

Is it possible to add vector tile sources (using MapBox's protocol buffers format, or GeoJSON, or otherwise) to QGIS? If so, how? (My question is a bit similar to Can the new Mapbox Vector Tiles be ...
1
vote
1answer
30 views

How can I allocate a $rownum in reverse order in QGIS?

How can I allocate the $rownum value in reverse order in QGIS? I have a created a grid layer to use in an atlas and the ID allocated is from top left to bottom right - which is what I want if I want ...
1
vote
1answer
48 views

Different definition of EPSG:3857 in GeoTools and QGIS

I want to do some checking if my point lies in any of the polygons defined in shapefile. So, I thought that I will determine CRS from shapefile (created in QGIS), and use it for transformation (where ...
1
vote
0answers
45 views

QGIS 2.8 topological editing creating vertices

When using the node tool with topological editing enabled on a group of multiple lines, double clicking sometimes doesn't create new vertices. Instead, the line segment gets selected. When this ...
3
votes
2answers
57 views

Loading Grass 7.0 vectors in QGIS broken?

Running QGis 2.8.1 in Win7 (64bits), installed through OSGEO4W. When trying to load a Grass 7.0 vector file in QGis, the program will simply crash without any notice. I can load old Grass vectors ...
2
votes
1answer
81 views

New filter expression QGIS 2.8

I try the new filter expression with QGIS 2.8. I want to filter only the selected objects on a layer in my map. My expression is: import processing from qgis.core import * vlayer = ...
1
vote
1answer
81 views

“ImportError: no module named qgis.core” in standalone app

I am developing a standalone app (in Windows) using libraries from QGIS. When I run the script in cmd, I get the ImportError: no module named qgis.core. I read in several posts that I need to ...
2
votes
1answer
45 views

Go through items in a composer legend (QGIS 2.6)

I'm trying to develop a plugin in QGIS 2.6, which opens a composer, add a map and a legend, and (among other things) adjusts the legend. Is there a way to go through items in a composer legend with ...
1
vote
1answer
50 views

How to georeference two pictures that do not have crs in QGIS

I would like to take aerial pictures of my research plots an caculate NDVI and NDWI. How do I do that in QGIS?
1
vote
2answers
42 views

qgis: how to use 'max()' in an expression

I wanna make a rule-based style on the maximum value from a field. I set my expression like: max("fieldname") It returns every value instead of only the maximum one. Can anyone tell me the richt ...
1
vote
0answers
33 views

QGIS actions - get currently selected attribute column (with python?)

I'm trying to open files dynamically through actions. A simple example would be: Action name: OpenLink from PyQt4.QtCore import QUrl; from PyQt4.QtWebKit import QWebView; myWV = QWebView (None); ...
2
votes
1answer
36 views

How to select lines/polygons in QGIS CAD tool?

I'm intending to create parallel and orthogonal lines by using the CAD tool in QGIS. For each tool there is a button to select the feature before executing the tool. But though I fixed all the ...
0
votes
2answers
96 views

Does QGIS data work in Esri CityEngine?

Does QGIS data work in Esri CityEngine? I have a copy of CityEngine Basic and imported a shape file which have the street network and lots. Without ArcGIS I can't open data which have building ...
1
vote
1answer
55 views

Is there any topology handler in QGIS?

When importing autocad maps, sometimes topology will be chaos, this need to be amended. And when I add new topology in QGIS, how to save that to the postgreSQL? Is these functions included in QGIS or ...
1
vote
0answers
19 views

Is it possible to have a locked/different first page with QGIS Atlas printing?

It is possible set the first page of a QGIS Atlas different to the other pages? For example I want to create an Atlas document where the first page has a text introduction and a general map (not ...
1
vote
0answers
26 views

What are the wider capabilities of the QGIS atlas functionality?

Given that it is already understood that the QGIS composer atlas function makes it possible to print separate pages based on a 'coverage' layer, what basic range of functions/outputs can be achieved ...
1
vote
1answer
18 views

Trouble updating attributes of a layer based on another layer's attributes if features intersect in python, QGIS

I am trying to assign attributes from features in one layer that intersect features in another layer. When I run my code, I do not get an errors but it does not update the attribute field as I am ...
2
votes
0answers
29 views

How do I trick QGIS's map composer into chopping off the 000's in UTM coordinates?

In QGIS 2.8 (ubuntu), you can create a map with ticks and labels. I want the first two digits to be smaller sized, the next 3 to to be normal sized, and hide the last 3 digits. QGIS does not offer ...
1
vote
1answer
31 views

Making centeroids for vector grid

I need to add polygon centeroids to vector grid but I cant... i have output grid like polygon, but i cant choose layer to make centeroids I need it for R studio and pollution model of city, thx for ...
1
vote
0answers
24 views

QGIS Polygonize (GDAL) problem - Null value in attribute

Is it possible to use Polygonize in QGIS (GDAL) so that a line shapefile is converted to a polygon shapefile with an attribute(s) in the line file carried into the polygon file. I am trying to build ...
0
votes
2answers
52 views

How to get a layer that is not active with PyQGIS

I want to retrieve attributes of selected objects on a layer with PyQGIS. All example I see is for the active layer: vlayer=qgis.utils.iface.activeLayer() selected_bf = vlayer.selectedFeatures() ...
6
votes
1answer
128 views

HERE background maps in QGIS possible?

The OpenLayers plugin for QGIS allows one to add background maps from various sources to the data frame. These sources include OSM, Google, Bing, MapQuest, and Apple. However, Nokia's HERE Maps, is ...
0
votes
0answers
28 views

How to overwrite/change attribute values with QspatiaLite in qgis 2.6

I tried to work on the "tbl_datum_transform" table which is included srs.db data file. Just to let you know... i try to fill in the ntv2 - BETA2007 grid. How can i fill in something in the ...
2
votes
0answers
34 views

QGIS WMS Server

I have successfully installed QGIS Server on Ubuntu 10.04 Lucid. The QGIS project file I want to publish as WMS was created with QGIS 2.6.1 The data is stored in shapefiles, the GetCapabilties request ...
0
votes
0answers
66 views

Error loading plugin photo2shape even after installing exifread module

I am new to any GIS and have been exploring QGIS software so we can eventually apply this technology to our agency. I am trying to figure out how can I install the photo2shape plugin successfully. ...
0
votes
0answers
30 views

Print Composer, multiple maps. Advice please

Im using 2.6 and am struggling to get 3 different maps in one print composer. Better explained, 1 map with the county, the 2nd closer viewed with the town and the 3rd with the actual woodland. Its for ...
0
votes
1answer
28 views

QGIS - Labeling with expressions

some polygons in my map have a "name" (but no "capacity") and some have a "capacity" (but no "name") and some have both. I want to label the polygons with the "name" and the "capacity". Therefore I ...
1
vote
0answers
24 views

Locating Coordinate Reference System Selector on QGIS [closed]

I downloaded the latest version of GQIS last Friday(6/3/15). I can't locate the Coordinate Reference System Selector. I have tried clicking settings, custom CRS, add CRS, but can't find a way to ...
3
votes
2answers
62 views

Calculating unique ID value for a field in QGIS using python

I am trying to calculate a unique ID field for a vector layer in qgis, using python. I found some code to calculate attribute values, and tried to increment the value in the expression, but it doesn't ...
1
vote
1answer
76 views

Trouble with heatmap plugin in 2.6.1

When using the heatmap plugin, I am getting some insanely large numbers for the cell size field when setting the radius to 5000. I know that rows and columns are related to cell size x and cell size ...
1
vote
1answer
34 views

Exploding multipart features in qgis using python [duplicate]

I want to explode a multipart layer to singlepart in python. I see through the qgis gui there is a way to do it under vector--geometry--tools--Multipart to Singleparts.. which does what I need, I just ...
1
vote
0answers
19 views

Merge CSV file to Vector Layer using common attributes in QGIS python scripting [duplicate]

I have a vector layer and a delimited text (csv) file -- they both have the common attribute attribid -- how can I add the columns of the csv file to the vector layer merging on the the attribid key ...
2
votes
1answer
132 views

wine + LAStools in QGIS 2.8.1, Ubuntu 14.04

I can't get wine + LAStools to work in QGIS 2.8.1 (ubuntu 14.04). I only get the 22 open source functions that comes with QGIS. Outside qgis wine + LAStools works fine. My guess is that I am not ...
0
votes
0answers
26 views

Installing postgis_viewer.py for pgAdmin III

I have difficulties installing pgAdmin's plugin postgis_viewer.py. The official repository on GitHub gives this Web site for install procedure, then the former site gives this Web site for installing ...
1
vote
1answer
34 views

Trouble buffering a vector layer in QGIS with PyQGIS

I am working on a script that imports a .csv layer that has lat long coordinates, which I then want to buffer in feet. I've created a vector layer from the .csv file and tried to set the coordinate ...
0
votes
0answers
55 views

How to export a high resolution .tif of a map with QGIS Print Composer

I have an high resolution image of a map in QGIS using the print composer. It has 300dpi and the final map would be near 12gB big. The system is a virtual server with 128gb RAM, means there are no ...
1
vote
0answers
65 views

Create diagonals in polygon with QGIS or ArcGIS

How is it possible to create the diagonals in/of polygons and to calculate the length of this diagonals afterwards. It's for a lot of polygons so maybe a fast/automatic method would be nice. I ...
1
vote
1answer
30 views

Selecting Features from the results of topology checker in QGIS

Is there is any way to select or extract features from topology checker plugin in qgis?
1
vote
1answer
31 views

Enlarging polygons in a kml file

I have a KML file containing several hundreds of Polygon all around the globe, projected in lat/lon WGS84, decimal degrees. I need to enlarge all the polygons adding 23km at the top and at the bottom ...
1
vote
1answer
55 views

QGIS tool for aggregating population data in fishnet

I'm looking for a tool or method to aggregate a vector fishnet based on a minimum value. Specifically, I have a fishnet containing a population value and I would like to join together cells that ...
2
votes
1answer
47 views

QGIS - Label outside polygon

is it possible to place a label automatically outside its polygon? Marcus
-1
votes
1answer
32 views

Which Qgis for OS X Yosemite?

Which Version of Qgis can I install on a Mac OS X Yosemite Version 10.10.2 ?