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

learn more… | top users | synonyms (1)

1
vote
0answers
18 views

how to calculate radius of curves in a polyline with QGIS

I have a polyline made of curves and I would like to know if there is a way in QGIS to calculate the radius of the curves?
1
vote
0answers
26 views

QGIS cannot open layer properties

I'm trying to open (vector) layer properties in QGIS 2.2.0 and 2.4.0 (Windows 8.1) and nothing is happening. The application freezes and not responding at all (requires cntrl+alt+delete to close). I ...
1
vote
0answers
23 views

ERROR 6: EPSG PCS/GCS code error when running QgsGeometryAnalyzer().buffer

I am trying to buffer points from a FileGDB in a PyQGIS script. I setup my environment with the following batch file and run the python script below. The problem is that I get ERROR 6: EPSG ...
2
votes
1answer
33 views

Speeding up processing of geotiff background for QGIS?

Originally I had an image as a mrsid file. That was very convenient as it was smaller and fast to pan etc. The down side was that every time I upgraded QGIS I had to go through the ritual of ...
2
votes
3answers
86 views

Is it possible to know which roads belongs to which districts?

I have two shape files: road layer and a district layer. Is it possible to know which roads belongs to which districts? I'm currently using QGIS.
1
vote
1answer
55 views

QGIS SLD in GeoServer

I rendert a beautiful with QGIS based on OSM data. Now I want to publish it via GeoServer. I am new to GeoServer but as far as I it does not accept SLD files created by QGIS. My GeoServer cannot ...
3
votes
0answers
23 views

Overriding the QGIS Feature Dialog

We are developing a QGIS plugin and would like to override the QGIS Feature Edit Form with our own Dialog. Have explored using setEditForm and setEditFormInit, but the init process appears to want to ...
2
votes
1answer
24 views

Broken Plugin: EOL while scanning string literal

I've written a python plugin, and it works perfectly on my pc (Windows 7). I've zipped the whole folder and sent it to the client. they report back with this (the name of plugin's folder is LTS): ...
1
vote
1answer
34 views

Convert and export lat longs from text layer - QGIS

I have imported a Text Delimited Layer that was a csv file with three fields id, lat, long. The layer shows up correctly and the values are in Feet. I need to convert the Feet to Decimal Degrees and ...
2
votes
3answers
163 views

Content for Introduction to GIS course using QGIS?

There is already a Q&A here at GIS SE on Where to find QGIS tutorials and web resources? but this is not a duplicate of that because it is about Instructor-led rather than On-line Training. For ...
0
votes
0answers
19 views

Problem with Performance when accessing selected Features from PostGIS layers in QGIS using Python

I have 2 PostGIS layer in my QGIS project. They have about the same amount of data and a similar structure except that layerX has its PK on a single column and layerY has its PK on 4 columns. When I ...
1
vote
0answers
12 views

How to read and write to .txt in layer properties, action tab?

I want to write a certain attribute to a .txt file using the action tab in the layer properties (combined with Hotlink). In the QGIS-2.2-UserGuide, on page 97, there is an example on how to do that ...
1
vote
1answer
54 views

Broken MSSQL provider in recent QGIS versions - has anyone experienced this?

I recently moved from QGIS 2.2 to 2.4.0 and in the process the MSSQL spatial data provider appears to have stopped working properly (behaviour is also the same with 2.5.0). QGIS will still connect ...
-3
votes
1answer
106 views

How to extract drainage line network from GRASS GIS and QGIS [closed]

Giving DEM as input is there any way to get drainage network? I am newbie to GRASS and QGIS ,provide any working examples in GRASS GIS and QGIS with procedure.
1
vote
1answer
46 views

leaflet and image popup from qgis export

I am a novice in using leaflet, I exported my map layers from qgis to a working leaflet map. i am trying to modify the popup to use the attribute so as to get an image popup. i am however stuck as i ...
1
vote
1answer
29 views

Geometry error in roadnetwork

I have a road network table. When I check st_isValid(the_geom)='f', I am getting an error: NOTICE: IllegalArgumentException: point array must contain 0 or >1 elements ERROR: Exception in ...
2
votes
1answer
28 views

QGIS Plugin development version compatibility

At this time latest QGIS version is 2.4 , QT Version is 5.3.1 and PyQT5.Are these version compatible with each other ? Once QGIS 2.4 is installed , how does one know which version of QT and PyQT(and ...
1
vote
1answer
55 views

What are the parameters for my connection QGIS

I am new QGIS, I was wondering what the parameters are for the New MSSQL Connection in the dialog window? Provider/DNS: ? when local ? tried leaving empty Host: ? when local ? tried my ...
1
vote
0answers
51 views

Convert polygon data into extreme lon/lat coordinates using QGIS

I'm very new to QGIS. I have a shape file of census blocks and want to use the data to plot points within each boundary using Google Maps api. I figure the best way to do this is to find the extreme ...
6
votes
3answers
145 views

How to combine raster and attribute table in QGIS?

I have some rasters representing string categorical variables. Each raster contains integers, used to translate the categorical variables. I have also the .csv tables giving the meanings of the ...
4
votes
3answers
170 views

How do I make data points different sizes based on data?

I am trying to plot sales data on a map using QGIS. I will add the disclaimer that I am a rookie at using the program. I added the different sales types by adding delimited text layers (utf16). The ...
0
votes
0answers
31 views

How to correctly render a raster Layer to GTiFF with QGIS python console?

I am trying to render a map from a raster layer. As recommended in pyqgis cookbook and here(osgeo.org) I use QgsMapRenderer(). I am able to produce a picture but it has not appropriate extent and ...
1
vote
1answer
40 views

How to create a photo-documentation in QGIS?

I would like to create a photo-documentation in QGIS for some real world objects. The photos aren't geotagged but I now their position on the map. If possible I would like to link them to a point ...
2
votes
1answer
51 views

Export raster from QGIS 2.4 to PostGIS

How can I export a raster file out of QGIS (version 2.4) into a PostGIS database? I am looking for a module or python script.
1
vote
2answers
102 views

Where/how to find ortophotos

I am very new to Geographic Information Systems. I have a very basic inquery; How do I get hold of the newest ortophoto of South Africa to use as a background map for my GPS data? I'm using QGIS but I ...
1
vote
0answers
57 views

drawing tools for (lines,polygon and points) in QGIS 2.4.0

I want to draw lines, polygon and points without necessarily creating a shapefile in QGIS. Please help
1
vote
1answer
48 views

How to create QGIS theme map?

I need to make theme map using diagrams like in MapInfo, can I do it in QGIS? Or can I create a surface using attributes?
0
votes
1answer
33 views

Delete empty attribute columns of a shapefile with QGIS or ogr2ogr

I have a shapefile with a lot of empty columns but many of them are empty. Using QGIS or ogr2ogr, how do I remove all attribute columns where everything is NULL?
1
vote
0answers
20 views

cadtool and spline plugins not working

Am trying to edit a line shapefile using a spline tool in QGIS 2.4.0 .Its drawing but the ok button is inactive. what could be the problem? Generally am trying to create a curved line.
1
vote
0answers
19 views

QGIS 2.2 - spectral profile for multilayer/time series

I am missing a spectral profile in QGIS which enables me to see the values for all bands of a given pixel. (absolutely necessary for multispectral and multitemporal/time series work) It seems, there ...
2
votes
0answers
18 views

Exporting attribute data from vector data by selecting object in QGIS?

I'm using QGIS (2.4.0), and i need to export the attribute data of the object i select (shapefile) to another file ( Excel, txt,...it is yet to be determined depending on the solution). I know how it ...
3
votes
1answer
76 views

Creating blended colour relief in QGIS?

I am mapping mountainous areas in QGIS 2.4 and would like to recreate the beautiful blended colour relief found, for example, in the map shown at http://maps.kartoza.com/Boosmansbos/. While I am ...
3
votes
3answers
46 views

Is there a way to shift data in an attribute table so that all attributes are moved to a different coordinate?

I have several shapefiles where the attribute table is composed of timestamped data that is appended to the coordinates. Because of the nature of my data, I need to apply a time lag so that the data ...
2
votes
1answer
31 views

Exporting QGIS shp file to dxf-Which dxf format?

As I understand it, dxf comes in a range of format types. QGIS (v2.0 'Dufour') can export any layer to a dxf file. However I have a hydraulic modelling package which relies upon importing the dxf file ...
2
votes
0answers
21 views

Using Space Syntax Analysis plugin for QGIS?

I'm trying to run the Space Syntax Analysis plugin for QGIS. I've added the metadata file that was missing, but it does not appear in the Plugin toolbar when I click on it. Can someone help me to ...
1
vote
0answers
16 views

Changing extent on a raster in QGIS

I rasterized a shape. The resulting raster (lets call it raster 1) has a different extent. I made a virtual raster with the original polygon and I tried to multiply the virtual raster with raster 1 ...
0
votes
0answers
24 views

Merging contour lines generated by gridded data

I have a set of gridded data, which I have used to generate contour lines based on separate values in the data. In the example provided the contour lines shown correlation coefficients. The contours ...
1
vote
2answers
42 views

How to get a contourline shape into ArcGIS or QGIS from an AutoCAD file

My question this time is about a request. I need to create an elevation profile and I know I can do that in QGIS 2.4.0 or ArcGIS 10.2. But first I need elevation data, information that is in AutoCAD ...
1
vote
1answer
26 views

32bit to 64bit topology errors

Can generating a shapefile from a pgdb cause topology errors due to floating point conversion? I am running into gaps in a line layer of really small distances (order of 10^-4; CRS EPSG:2227 usft). ...
2
votes
2answers
61 views

Is it possible to pan the map in QGIS composer?

I am relatively new to the composer feature of QGIS, and often have difficulty getting the map centred exactly where I want it. In particular the area of interest often moves when I set the scale. Is ...
1
vote
0answers
14 views

QGIS UTM zones - TIN interpolation plugin

I am trying to add a Z-variable to a vector in order to eventually calculate the volume or the zone using TIN. I was told I first need to set my UTM in order for my Z-variable to be recognized in ...
3
votes
1answer
58 views

Underwater terrain modeling

My task is to model the surface of a lake bed, calculate volume of it and visualize it as 3D a surface. I have acquired depth measurements in a small lake using echosounder. The precision should be ...
3
votes
2answers
60 views

Analysis of lines in a point in QGIS

I have 33 layers, 1 with points and 32 with lines. I want to extract/highlight the points where more than one line is intersecting. I have tried with buffers but I'm not getting anywhere.
1
vote
1answer
35 views

How to properly import QImage from PyQt4.QtGui?

I am starting with QGIS python console. Naturally, I came across the PyQGIS Developer Cookbook. While trying to cut my way through it, I encountered a lot of problems with "undefined attributes and ...
1
vote
0answers
16 views

QGIS - Auto-Update Color-Ramp to Current Display Extent

When displaying raster files in Qgis with the color-ramp stretched to the min/max values of the current display extent, the min/max values don't update automatically when zooming or panning to a new ...
0
votes
1answer
32 views

Is it possible to create one raster elevation layer from two different point layers in QGIS?

[I edited this question after recieving some helpfull comments from users]. I have two layers with X,Y,Z data. The data overlay only partly. Is it possible to create one raster layer with elevation ...
2
votes
0answers
39 views

best method for gridding or interpolating elevation data

I wonder if someone can recommend the best method for gridding elevation data in QGIS, GRASS or similar. The elevation data I have is collected along 1m spaced lines at approximately 1 reading per ...
3
votes
0answers
34 views

Is there a limitation on the numbers of layers that can be displayed in QGIS?

I have been looking for an answer to this question for the last several weeks, so hope that someone here has encountered the same issue and has a viable solution to my problem. I am currently using ...
4
votes
2answers
45 views

How to programmatically delete all inner rings of a polygon layer?

I have many polygon layers, each layer containing many polygons with inner rings. I know that you can delete a ring manually with QGis (Edit -> Delete ring). I need the python equivalent to ...
0
votes
0answers
20 views

What is causing this QGIS processing model to fail at r.mapcalculator

I can't figure this out. I can run a number of tools from the processing toolbox separately with success but when I string them together in a model it keeps failing (image of log below). It looks ...