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

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3
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1answer
56 views

How to change the “application_name” of a PostGIS-connection in QGIS?

PostGIS offers a view called pg_stat_activity, where you can see all the active connections to the database. This view includes the interesting column application_name. When a connection comes from a ...
2
votes
3answers
65 views

Strange coordinate system [closed]

Here's an extract of a feature from the web that I converted to geojson using qgis. However, the coordinates are not standard are at all and when trying to actually preview it on the web it fails, ...
2
votes
1answer
34 views

PyQGIS: How to get the list of valid layers in TOC?

To get the list of TOC layer names I used the approach suggested here: for layer in QgsMapLayerRegistry.instance().mapLayers().values(): print layer.name() But this method is not reliable due ...
1
vote
2answers
59 views

Is it possible to split a picture taken with a regular digital camera into real spectral RGB channels?

I have no idea how the sensors inside a camera work. I know I can take jpeg and separate the R, G and B channels but I have no idea whether these channels are the real red, blue and green in visible ...
1
vote
1answer
20 views

How to remove group filter applied via Python-console (setSubsetString) of QGIS?

I need to quickly applie (and then change/remove) the same filter for about 100 layers in my QGis project (all put together in one group). Since there is no implemented solution right now (a feature ...
1
vote
1answer
22 views

Adding New Linear Feature using QGIS?

I am new to QGIS (2.6.1) and am having trouble adding a new linear feature to an existing layer. I have set tolerances and digitized the vertices of the line and it terminates with a large green X at ...
2
votes
0answers
31 views

Create a sript for “point sampling tool” of QGIS

Is there any way to create a python script to the "point sampling tool" plugin from QGIS? I have a very large number of Netcdf files which I want extrat the values from pixels to a irregular points ...
0
votes
1answer
25 views

in a single vector layer I have a three of polygons with different field values (e.g1,2,3). How Can I color each field value polygon differently?

In a single vector layer I have a three of polygons with different field values (e.g1,2,3). How Can I color each field value polygon differently? To explain a bit more my three polygons are showing ...
0
votes
1answer
28 views

Bing Aerial metadata in QGIS

I am using Bing Aerial imagery within QGIS through the openlayers plugin. How can I find the dates of the images that are within the map canvas? Thank you Becky
1
vote
1answer
26 views

Is it possible to not show node in editing mod QGIS

I actually have a plugin that allows me to draw on a vector layer (I made it based on the FreeHand Editing Plugin). When a mouseMoveEvent is detected, it creates a new point on the vector layer and ...
0
votes
0answers
38 views

Setting up QGIS-web-client on windows server 2012

Recently I've started working on a project which will require a website written in C# (.aspx) and will also use the free and awesome QGIS-web-client. Because of this I've decided to use windows server ...
0
votes
0answers
22 views

QGIS File Geodatabase Vertices missing

I am adding Data from a File Geodatabase to QGIS. Everything is working fine, but the drawing of a specific Line subtyp (first image). It looks like, QGIS can not draw the circle properly. An export ...
1
vote
1answer
45 views

QGIS 2.8 starts with an error and I am not able to run Python console

I have installed QGIS 2.8 - Wien on Linux Red Hat 7. Unfortunately when I start the application I got this python error: {Couldn't load plugin 'processing' from ['/usr/share/qgis/python', ...
3
votes
2answers
68 views

Need a vector format that is editable in QGIS and supports >10 character column names

For reasons, I need to create a new column in a vector shapefile with a name longer than 10 characters, and export to mapinfo TAB format. I know .shp's don't support >10 character column names, so ...
0
votes
0answers
29 views

Raster (Tiff) to KML for Google Earth Overlay - QGIS

I am trying to convert some raster files to KML in QGIS for overlay in Google Earth. They are really huge Tiff files as I processed them from 3 meter DEM datasets. I have been searching the web and ...
1
vote
1answer
29 views

Classify values from table

I would like to classify several values from a vector table with field calculator in 5 classes based on standard deviation. Example: value = 3.3, mean = 2.5, std deviation = 0.7 and class #5 is ...
2
votes
0answers
24 views

How to automatically refresh canvas after saving layer edits

After saving a layer edit in QGIS 2.8.2 (Win7) I've to press F5 or change the map section to refresh the canvas. This is quite annoying when working with dynamic PostGIS views. Is there a way to ...
1
vote
1answer
40 views

How can I implement animation with lines using QGIS TimeManager?

Among all the examples I saw, I can only find those with animated dots. I need to implement a time slider based on each link's capacity, and display different colours according to the magnitude. ...
1
vote
0answers
26 views

Zonal Statistics for multiple rasters

I'm trying to create a timeseries of raster data (one layer per year) by polygon (Administrative regions). Is there any way in QGIS to perform Zonal Statistics for multiple years (without having to ...
0
votes
1answer
8 views

Hub Distance - 'Layer not found'

I am trying to calculate the distance between a polyline (River) and multiple points. However after installing the MMQGIS plugin and running a Hub Distance between the two layers the error comes up ...
1
vote
1answer
42 views

Using the Function Editor to replace special characters

I am attempting to use the new Function Editor within QGIS 2.8.2. I have a field called LAND_NAME with hundreds of rows. What I'm trying to do is find and replace all "special characters". In ArcGIS, ...
2
votes
1answer
34 views

How to display map tips only for one layer?

I'm relatively new to QGIS. I added the hover labels to my map using the Map Tips. My issue is that it makes hover labels for EVERY layer on my map. I only want it to make labels for one layer. Is ...
1
vote
1answer
11 views

QGIS Graphical Modeler Help editor does not save

Is there a special way to save whatever text you're writing in the Help Editor for a QGIS Model? I've been trying a few times, apparently just after I click ok, even though I immediately click "save" ...
0
votes
0answers
38 views

Python snippets from QGIS

Out of curiosity and perhaps for practical reasons, is there a way to obtain Python snippets from QGIS 2.8 the same way you do in ArcGIS? Please don't redirect me to some other question that looks ...
2
votes
1answer
146 views

How to fill a hole - with islands within?

In QGIS I have simplified a layer. At the end of the simplification process (using GRASS v.generalize), my final layer "lost" a polygon: see white space in image: How can I recreate a polygon which ...
2
votes
2answers
34 views

How to list data in the attribute table in the same order as I selected the data?

I have a map that consists of a number of pipes that are connected to each other. Is there a way I can list data in the attribute table in the same order as I selected the data? For example: I select ...
1
vote
1answer
18 views

Change page setup in composer window using the QGIS API

Is it possible to use the QGIS API to change the orientation within page setup in the composer window. We have a plugin that builds a map template based on user defined options. When they choose to ...
4
votes
1answer
151 views

Why can't I copy values from a virtual field to a non-virtual field using PyQGIS?

Using the python console, I am trying to copy values from a virtual field into another non-virtual field. Both fields are integer types but I get NULL in the non-virtual field. I followed the answer ...
1
vote
0answers
66 views

Using GPS to field walk through a LiDAR scene

I am doing field surveying for archaeology using Lidar. If I attached a USB GPS to my laptop would it be possible to track where I am "in real time" on the Lidar as I am field walking? I'm wanting to ...
2
votes
0answers
25 views

Delineate new political boundary in dataset

In the political area I'm working on, there has been a recent formation of a new city, legitimized with government plebiscites and resolutions etc. Geographically speaking, it's still the same land ...
3
votes
2answers
83 views

Understand QGIS errors when importing .csv file

I am trying to import a .csv file as a layer in QGIS and keep getting a number of errors that I don't understand. Is there any documentation of QGIS errors available? Or can you point me towards a ...
1
vote
1answer
52 views

Cannot install “Processing” plugin on MacOS + QGIS 2.9.3, fresh install

I have just installed a new MacBook Pro and QGIS, everything is fine but this strange error if I try updating or reinstalling the "Processing" plugin. The plugin is broken. Python said: cannot ...
1
vote
1answer
37 views

Joining Parcel/Building Attributes Based on Coordinates

GIS noob here: I downloaded a building footprint shape file for a city and imported it as a vector layer in QGIS. I was hoping to see street address information in the attribute table, but there was ...
2
votes
0answers
26 views

How to make a model with more than 2 input layers for buffering and merging?

Would it be possible to add more inputs to Buffer and Merge? From what I can see there is a limit of two input layers per both. As far as I know this is possible in ArcGIS's Model Builder but from the ...
3
votes
1answer
42 views

How to change font color in one column of attribute table in Composer reports?

How do you change the font color in just one column of the attribute table included in QGIS's Composer? I would like to have the numbers listed in color red just for one column out of four columns in ...
1
vote
1answer
59 views

How to create a line between a point and nearest neighbour using python (template included)

I have 2 shapefiles - one is a series of points, the other is a polyline. I want to draw a straight line between each point to the nearest point on the polyline. This question has already been asked ...
1
vote
1answer
24 views

Adding point layer in QGIS from SQL Server failing

I just downloaded QGIS a few days ago (version 2.8.2-Wien) but I am not able to get it to work as I thought it would. I tried pulling in spatial data from sql server (a "geometry" column containing ...
0
votes
0answers
13 views

GRASS watershed analysis add storm inlets

Try searching for this with no luck. I am using r.watershed to delineate flow directions, subwatersheds, etc. All good, except that storm drain inlets, culverts and subsurface drainage courses are ...
1
vote
1answer
111 views

Problem with Memory storage type in PyQGIS when updating with auto form

I have a layer of "Memory storage" type (Memory provider) which I created with Python. When editing=on and updating values using the attribute table interactively everything works as expected, i.e. ...
0
votes
1answer
29 views

Combining multiple overlapping rasters - retain maximum value?

I have 40 overlapping raster grids (derived from flood modelling software) that I want to combine in such a way so as to retain only the maximum value in any of the given rasters at each grid ...
0
votes
1answer
50 views

How Can I Create a Tin from Elevation Points in QGIS

I have a shapefile of points with values that represent elevation at the given point. I know that I can create a TIN from these points, but the fields in the TIN do not represent the elevation. ...
1
vote
0answers
13 views

Does fixed classes exist in QGIS?

I'd like to create several images of voronois polygons in QGIS; each images having differents values joined to the voronois. I tried to load a qml style with the values I want to keep (8 classes : ...
1
vote
0answers
14 views

Overlapping polygons: how to sum attribute values for areas where multiple polgons overlap [duplicate]

I have what seems to be a fairly simple problem but I cannot find a solution. Any help would be much appreciated. I am working in QGIS 2.8.1. I have a shapefile of polygons, each of which has a ...
0
votes
1answer
55 views

Combine several rasters in QGIS

I have a problem combining several rasters into one big raster. Particular annoying is, that I had this problem once before and solved it, but I can't remember how. Unfortunately the other ...
0
votes
1answer
34 views

QGIS DB Manager - load as new layer not loading

After successfully running an SQL query on two tables and some results in 3 columns, I would really like to be able to display it in the canvas. Apparently, that function is not doing anything, not ...
1
vote
0answers
40 views
+50

Editing data in QGIS Server via WFS in AutoCAD Map (2015)

I have a QGIS Server up and running. I can consult my layers using WMS protocol and edit them using WFS protocol in QGIS or lizmap web client for example, but I am not able to make it work in AutoCAD ...
2
votes
0answers
32 views

QGIS' Join Attributes by Location not working from Python script

I have a shapefile with points, and a shapefile with polygons. I want to sum the attribute value of all points that are within a certain polygon, and I'd like to do this for each polygon in my ...
2
votes
1answer
27 views

PyQgis - saga:catchmentareaparallel parameters

in PyQGis i want to use saga:catchmentareaparallel algorithme, in the parametres there is an optionnel arguments , and i don't want to use theme , what is the value should i put on the argument?? i ...
2
votes
0answers
16 views

Relative path in layer styles in spatialite

is there way to store default style in relative path in spatialite??it has layer styles table,and a column 'f_table_catalog'.and in this column pathes are absolute,In Qgis project options i set ...
1
vote
0answers
36 views

Algorithm for re-numbering duplicate feature IDs based on distance along line (PyQGIS and QGIS 2.8)

I've got something working for QGIS 2.8 using Python 2.7 on Windows 7, but I am missing an important part of the puzzle. I'm trying to develop an algorithm to number homes. I've now come to a point ...