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

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3
votes
1answer
129 views

Is it possible to label bar charts?

I have added bar charts to my map and this works fine. But I have no idea how to add values to the bar chart. For example one bar shows the value of 2000 and another shows the value of 2100. Is it ...
0
votes
0answers
9 views

Clipping rasters in Qgis

I'm having some problems clipping rasters... I started clipping my raster using extents, but I saw that the clipped raster is different from the original raster. I created a virtual raster to use as ...
0
votes
0answers
13 views

Routing and Validating trip mileage with open source software

I am looking for ways to validate mileage charged by our contractors. They are paid from a central location to a customer, and then from the customer to a drop off location. I use QGIS for a bunch ...
0
votes
1answer
16 views

Cannot load postgis layer from sql string in pyqgis

I'm trying to load a layer using the following code in qgis python console: sql = "(select the_geom, ID from mytable)" uri = QgsDataSourceURI() ...
1
vote
1answer
19 views

In QGIS, is it possible to save graduated styles to use on different columns?

I'm using QGIS to produce thematic maps of 9 quantities (given in 9 columns in the attribute table) which have values broadly within the same range and I would like to plot them using the same ...
1
vote
1answer
18 views

How can you create a depth raster from a DTM and a polygon in QGIS?

I have a DTM raster and a flood outline in polygon format - how do I create a depth raster for the flood outline (i.e. flood level minus DTM level)?
3
votes
1answer
26 views

Using QGIS to create a table of correspondence between two area layers

I have two area layers over a map of Australia, and I want to know if it's possible to use QGIS to create a table of correspondences between them. The Australian Bureau of Statistics provides ...
0
votes
0answers
11 views

How to reference a number variable in r.mapcalc within QGIS graphical modeler

I need to run the following formula in r.mapcalc: (xor(abs(A-B),abs(A-C))>120)*A I would like to however use a user defined number input variable instead of the 120. I already have this variable ...
0
votes
2answers
21 views

kml does not overlay correctly in QGIS

In QGIS, when I insert a kml contour that was created in Google Earth, it appears misaligned in respect to all the other layers. Note in this image how the red contour is moved upwards with respect ...
2
votes
0answers
40 views

Double labels in QGIS

I want to create labels like a fraction using data from two columns. I have tried to use: "Field" || '\n' || '――' || '\n' || "Field2" but it doesn't look good. How can I do it using other method? ...
1
vote
1answer
96 views

Analyse slope gradient from LiDAR .asc data

I'm new to using QGIS. I have purchased some LiDAR data which downloads as .asc format, is there a way to analyse the terrain slope angle from this data or does it need to be converted into DEM? ...
10
votes
4answers
4k views

How to create equidistant points in QGIS?

I am trying to create points (new layer) at specific distance along the road (existing layer) in QGIS. This gives solution for ArcGIS. How to achieve this in QGIS? This one explains how to create ...
0
votes
0answers
15 views

insert row into postgis query table in QGIS

I find I am using QGIS (2.4) more and more as a client for PostGIS database tables with geometry, but also for tables without geometry, partly because it's good just to use the one application and ...
1
vote
0answers
13 views

How to create a svg item onto Map Canvas in QGIS API?

I'm working on a project with QGIS-2.4.0 API using C++. I need to load some svg files to the application for displaying as symbols. QGIS API has a class named QgsMapCanvasItem, which is an abstract ...
1
vote
0answers
23 views

Creating Form in QGIS

I want to create a form for editing attributes in QGIS. I have a lot of question and hope somebody can suggest how they work or where I can read about the next elements of form: Classification List ...
0
votes
0answers
15 views

Is there an editing function in qgis cloud? [on hold]

does someone know if an editing function exists in qgis cloud? or maybe is planned?
1
vote
1answer
28 views

Reprojected Shapefile does not align with Openlayers Plugin

I am based in NSW, Australia. I have a shapefile that when I underlay with the openlayer plugin (google satellite), the shapefile is skewed despite all my efforts to correct it. I changed the ...
1
vote
0answers
38 views

Dark Object Subtraction QGIS

I'm trying to do Dark Object Subtraction (DOS) for a Spot2 and 4. I have calculated the TOA reflectance and now want to get the at surface reflectance. Using QGIS I would like to know how I can do ...
2
votes
1answer
27 views

How to store a password during one QGIS work session?

I'd like to get into qgis-plugin development, but am rather new to both python and QGIS development. I intend to write a plugin which connects data from a mysql database to shapefiles. As the data is ...
3
votes
2answers
35 views

QGIS doesn't create the correct projections when creating new shp files

I received shapefiles exported from ArcGIS with EPSG:2227 as the CRS, which should be: +proj=lcc +lat_1=38.43333333333333 +lat_2=37.06666666666667 +lat_0=36.5 +lon_0=-120.5 +x_0=2000000.0001016 ...
1
vote
0answers
14 views

Can HTML annotations be autogenerated for each location in QGIS 2.4

Can HTML Annotation Boxes be autogenerated on the whole map, linked to locations, and always have the same html file loaded for all of them?
4
votes
0answers
250 views

How do I install Orfeo toolbox and Qgis 1.9?

I'm having a lot of trouble getting Orfeo toolbox and Qgis 2.0 working. I followed the qgis wiki instructios, added the ppa, installed qgis 1.9 (it's beautiful, great work!). But when i tried to ...
0
votes
1answer
119 views

Problem executing Mean Shift Segmentation

I have a problem executing the Mean Shift Segmentation in QGIS with Orfeo Toolbox. I put all the parameter to execute and then, nearly 5s after appear the message that SEXTANTE could not open the ...
0
votes
2answers
50 views

How to style graduated using size-scale field

Is it possible to style based on size-scale field using graduated symbol but instead of using color ramp, I would like to display its size. I would also like to display this in the legend in the map ...
2
votes
2answers
54 views

Deleting unconnected lines with QGIS

I am using a road map in shapefile format in order to calculate a route between two points. The map is downloaded from OpenStreetMap and it has small unconnected lines that are messing up my routing. ...
10
votes
4answers
9k views

Changing CSV layer attribute value from text to number in QGIS?

I read in a CSV file for linking to a .shp file. All the variables that are just numbers came in as text. How do I change the text variables to numeric in QGIS?
1
vote
1answer
44 views

Setting up QGIS Server at low cost for small user community?

I want to setup QGIS Server at a low cost for a small user community (mainly me). Parameters: Some data is private so something like qgis cloud not an option (not enough money for paid option). ...
1
vote
1answer
42 views

How to use bold text in QGIS font marker symbol?

Is it possible to use bold text with the Font marker symbol in a QGIS (point) layer?
1
vote
0answers
53 views

Cannot Save Edits to File Geodatabase Replica in QGIS 2.2

When trying to edit a File Geodatabase Replica in QGIS 2.2, everything works as expected until the user saves their edits. When pressing save, all edits revert back to their original state with no ...
4
votes
1answer
186 views

How to include streaming media into an OpenGeo system to monitor live-tracked animals?

I am wondering how to include streaming media (video), or camera feeds, into an OpenGeo system to monitor live-tracked animals. I am currently doing so with different applications, but I want to do ...
4
votes
1answer
114 views

Calculating a Unique ID on a Subgroup of Polygons

I would like to assign a unique ID to polygons in a dataset. The catch to my issue is that I would like polygons that fall within a polygon to have the same unique ID. My example is related to ...
0
votes
1answer
124 views

Merging Raster: ImportError: No module named _gdal_array

When I try to merge rasters I got following error message: _gdal_array = swig_import_helper() File "C:\PROGRA~1\QGISDU~1\apps\Python27\lib\site-packages\osgeo\gdal_array.py", line 18, in ...
2
votes
1answer
33 views

QGIS Intersection problem

The QGIS Intersection tool is not working for two shapefiles in Version 2.2 or 2.4 (haven't tried earlier versions). I get a new shapefile with all the attributes, but no features. However, when I use ...
1
vote
0answers
23 views

Is there a way to automate POI collection from websites?

I am searching for an easy method to get lots of points geotagged/georeferenzed into several shape files. I am working at a project where I need to collect all parcel shops in germany (but I will try ...
1
vote
1answer
31 views

What's the reason for this Invalid Layer “Cannot open GDAL dataset …” error

When adding a rasterfile with QGIS python console there appears an error when the first letter of a rasterfile to be added is not written in capital letters. Why this behaviour? Example case1: ...
0
votes
2answers
854 views

How to fix ImportError: cannot import name MAXREPEAT on Ubuntu 12.04

I have problem with installing qgis 2.0 on ubuntu 12.04. If I don't install qgis-python plugin then qgis starts normally but I can't access python console in plugins. If I install that plugin then I ...
3
votes
2answers
224 views

Load and display a layer using PYQGIS

I'm having a go at using pyqgis from within the QGIS python console to load a layer from SQL Server and display it. I feel like I'm part way there but I'm having a real issue getting the layer to ...
2
votes
1answer
383 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 ...
1
vote
2answers
2k views

Exporting shapefile to PostGIS database in QGIS

How do I export a vector shapefile to PostGIS database? I am asking what format I have to export it.
5
votes
1answer
100 views

Is there a simple way to sort layers alphabetically in QGIS?

I am working on a big GIS project and not being able to sort the items in the Layers panel is giving me hard time. I can have up to 250 layers in the Layers panel. I have a special naming scheme for ...
0
votes
0answers
30 views

How to combine Polygons and points? [on hold]

Sorry for the basic question. I'm using qgis. I have two layers, one with points (a file that contains addresses with latitudes and longitudes linked to several variables), and another layer (a ...
1
vote
2answers
130 views

Using Qt Designer to Create a Form in QGIS that can search for a specific point in a layer

Good Day! I would like to ask if you can create a form in Qt Designer to create a form that can search for a point on the map using data that the user will provide such as the Name. I am currently ...
1
vote
2answers
58 views

Creating counties in QGIS

I have a raster map (a photocopy I took from an Atlas), and a vector map of the UK. The raster map shows pre-1890 Scottish county borders. I have geocoded the map so that the raster borders overlap ...
3
votes
2answers
225 views

Per-pixel (statistical) calculations on a raster stack using GDAL

In R, it's relatively trivial to perform per pixel calculations based on a raster stack (e.g., get std.dev for each pixel on a 12 layer GeoTIFF). Unfortunately, the speed is less than desirable when ...
3
votes
2answers
179 views

How to calculate the square root of a feature attribute?

I have a polygon shapefile with over 16k features. Each has an attribute (Double, Precision(10) Scale (2)) that I am trying to calculate the square root of, and store in new field. Is there a tool, ...
4
votes
0answers
36 views

How do ESRI and QGIS calculate scale values of geographic projections?

Does anyone know how (from which location) scale values are calculated in ESRI products and QGIS for geographic projections? The only thing I've noticed is that QGIS is changing scales when you pan ...
0
votes
1answer
137 views

ArcMap reports that PostGIS polygon data is self-interescting

I have an ESRI File Geodatabase of data that I upload to PostGIS using FME. Seeing as I have to have the data in PostGIS for other purposes, it would be great to view the data in ArcMap straight from ...
0
votes
1answer
110 views

How Can I Merge Geocoded Addresses With a Shapefile and Export One Table?

I currently have two layers in my QGIS (v1.7.3 for Mac) project -- one being a Pennsylvania State House shapefile and the other being 166 geocoded addresses (for which I used 'Add Text Delimited ...
14
votes
1answer
346 views

How to query OSM for all beaches facing west? - QGIS preferred

I want to identify all beaches on this planet (or a given subset of it) that are facing westwards (+/- 20-30 degrees). My idea is to use OSM as the data source. Extracting all polygons that have the ...
4
votes
1answer
141 views

QGIS 2.0.1 linking table issue, MSSQL 2008 database

I'm trying to link tables in QGIS 2.0.1 and MSSQL 2008 database. I can link them but when I try to open the attribute table QGIS throws an error and shuts down creating a *.dmp file. I saw that ...