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

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0
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1answer
5 views

QgsFeatureList features as QStrings

I am catching the selectionChanged signal and passing the selected layer to the registered method. Once here, I want to know the features that were selected. I do this with a call to ...
4
votes
0answers
45 views

How to do Manhattan Voronoi on QGIS?

I've spending last two weeks trying to discover how to do a Manhattan Voronoi on QGIS. For the difference between Manhattan Voronoi and "normal" Euclidean Voronoi, please check this link Can someone ...
2
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2answers
15 views

QGIS Mosaicing with null values in images

I have a set of landuse landcover data which needs to be mosaiced. Whenever i try using QGIS Raster>miscellenous>merge tool. giving no datavalue as '0', it returns either (A) ' Traceback (most ...
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0answers
19 views

C++ and Quantum GIS

I wish to develop/customize with a combination of C++ and Q GIS (Windows OS). I downloaded QGIS but couldn't find header (.h) and library (.lib) files. Where can I find them?
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0answers
14 views

Programmatically modify layer datasource on project save event (QGIS)

I have a QGIS plugin which allows users to add WFS/WMS layers to the map. I would like to be able to scramble the user ID part (token) of the uri when the project is saved/closed and then use my own ...
1
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2answers
69 views

How does one export the list of stored WMS-servers in QGis?

Could anyone point me as to where QGis stores the list of WMS-servers you added? I have built a fairly large list of WMS-server on one computer, but the QGis-project file which gets accessed by my ...
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0answers
21 views

QGIS custom form and autocompleted data entering with “validation check”

In Qt-Designer I created a custom form where I can choose serveral species names in two different combo boxes. This combo boxes are linked via "value relation" to the accordant non spatial tables ...
1
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0answers
23 views

length and width of polygon

how can i find polygon's length and width in Qgis(regular polygon and irregular polygon)? i have area and perimeter but possible to have length and width ?.
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0answers
9 views

argument 1 has unexpected type error when parse xml with ElementTree

I try to make plugin in QGIS Dufour to open and read xml metadata and then to show some information in metadata i try to parse it with ElementTree and then show it in QLineEdit, this code i use to ...
6
votes
3answers
146 views

Merge images first, or georeference first?

I'm wanting to georeference and vectorise some features from scans of the OS 1896 Town Plans that I have purchased from the NLS (http://maps.nls.uk/os/london-1890s/info.html). The scans provided are ...
0
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0answers
18 views

Help Qgis cloud [on hold]

I need help for one problem. I want to publish my map, but they are one error for load data, i have my firewall shutdown, the shp don't have spaces and -., but the error persist. You can help me? One ...
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0answers
14 views

QGIS-QT designer. How to create a form that allows editing elements linked by one to many relationship

I know this question has been already asked on this forum, but I really have not found any answer, not here, not anywhere. My question is simple, I have a Spatialite DB having one spatial layer (Pole) ...
1
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2answers
35 views

Where are QGIS application setting file(s) stored?

I have some application settings (Windows/QGIS v2.0) that I would like to pass to other users (such as those settings defined under Settings menu>Options>Rendering tab). In ArcGIS they are stored in ...
1
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0answers
22 views

Is there a decent algorithm in QGIS Process Modeller to create a grid?

I am using Process Modeller to automate merging several vector layers and then creating a grid to cover the extent of the merged layer. There are functions which already exist which are not listed in ...
0
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0answers
12 views

QGIS: graphical-modeler to calculate area of polygons

I'm trying to calculate the area of polygons using the field-calculator in QGIS (2.0.1). If I do this manualy it works fine, but if I do this using the graphical-modeler I get NULL as area for every ...
1
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0answers
32 views

How can I see the overlay of two features (point & polygon)?

I am trying to open two digitized layers, one containing points in a region and second which I have downloaded separately for the region as polygon layer. I would like to overlay two of these layers ...
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0answers
8 views

Why there is no output (path) for Dijkstra in pgrouting

I have a road network table and I am implementing pgRouting. everything was working fine previously but now there is something odd here. I am getting no route now. I am checking through sql query in ...
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0answers
15 views

not able to use R 3.0 in qgis 2.0 desktop version

I have installed Qgis 2.0 desktop and R 3.0 . when i want to access R scripts in Qgis gui, not able to work why. may i know whether it is correctly installed or not. i have given R folder path ...
0
votes
1answer
28 views

How to use QGIS field calculator to delete style code?

I am struggling with following issue: How to delete style code before id codes x.x.xx.. and the }s in the end? Examples below. Any help appreciated! {\fArial|b1|i0|c0|p34;A.B.11} ...
0
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2answers
35 views

How to make multiple qgis mapbook pages in 1 pdf?

Is it possible to export a mapbook in QGIS 2 with multiple pages all in one PDF? Thanks
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0answers
27 views

How to add Georeferenced PDF as layer to QGIS 2.0?

I have some georeferenced pdf's that I would like to open in Qgis. I have read that GDAL version 1.8 and higher will support pdf, and I have GDAL 1.10 installed with Qgis 2.0 on windows 7, But when I ...
1
vote
1answer
36 views

Spatialite Table Difference in QGIS

I am see differences between tables when I view them in spatialite-gui and in QGIS. I have created a table, added columns, and updated the columns in spatialite-gui. Within spatialite-gui I can view ...
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0answers
16 views

Error: .asc is not a supported raster data source

I am new using QGIS and struggling with this error "...... .asc is not a supported raster data source" when trying to add a ."asc" file as a raster. I downloaded the files from ...
0
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0answers
25 views

QGIS locks up when loading shapefiles [on hold]

I have QGIS loaded onto a handful of computers within an organization. One of the computers is giving me a headache. When I try and load any shapefile from a network share, QGIS 2.2 or 2.0 freezes. ...
0
votes
1answer
29 views

Mac QGIS files to Windows Arc GIS compatibility

If I download QGIS on to Mac will the shapefiles and layers I create be compatible with ESRI ArcGIS 10.1 on windows?
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0answers
14 views

Error 14: Could not open CRS database

I am using Python Console and loading a Vector Layer using python commands. When the layer is added, QGIS first asks for the CRS to use, but I don't have all the CRS listed out to select the Reference ...
1
vote
1answer
46 views

extract shapefile attributes from raster colors

I have two layers: a shapefile with states and counties (shp) a raster file (with colors and some text and borders, but not a perfect map) (tiff) I want to use the colors in the raster file to ...
-2
votes
0answers
50 views

List of GIS software that runs on a server [on hold]

OK, I searched to see if this had been asked, but couldn't find it. I'm looking for a list of GIS software that will meet my needs listed below. Runs on a web server (this is where the other lists ...
0
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0answers
21 views

HTML Annotations

I am trying to insert html annotations into my map. I was hoping they would be interactive and pop up as you move over or click on a feature, but they don't seem to function this way (that I can ...
1
vote
2answers
52 views

QGIS Select by Expression

A basic QGIS 2.2.0-Valmiera, Select By Expression - Field Calculator question. Introduction I am a geologist searching through a geological database (see attached figure). I have a shape file and ...
-5
votes
0answers
24 views

How to add button in google maps where i have polygon? [on hold]

we are plotting polygon on google map using script.I want to add one button where my polygon plots. Using Front end as .net we are plotting polygons in google map.We need to add one clcked button on ...
3
votes
1answer
126 views

Unable to get python-qgis-common on Kubuntu 14.04

just upgraded my Kubuntu from 13.10 to 14.04 LTS and lost all plugins. Found out that "python-qgis-common" is not installed. Tried to install it but was told that it depends on "sip-api-10.1" which ...
1
vote
1answer
26 views

Split a line feature using nearby points

I have a line shapefile and a point shapefile, and the line has its own segments and its attribute table, the point shapefile has points near the line above, not on it and the close ...
0
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0answers
15 views

QGIS 2.2 Changeing txt data in theme table not working

A week ago I upgrade from QGIS 2.0.1 to 2.2 and try to edit some simple point themes I made recently. To my surprise, QGIS 2.2 randomly - not allways, does not allow me to change text I type into text ...
1
vote
1answer
148 views

QGIS crash Ubuntu 14.04

Encountering a crash when requesting QGIS 2.2 to access data on desktop machine. Running Ubuntu 14.04 LTS. $ qgis Warning: loading of qt translation failed [/usr/share/qt4/translations/qt_en_AU] ...
0
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0answers
12 views

Split/Erase/Differentiate polygon by polygon within a same layer

Is it possible to split a polygon with a polygon within the same layer in QGIS ? As in the image, i want the Polygon 2 to be split & the pointed area has to be retained as a separate polygon. ...
0
votes
1answer
17 views

Building with MinGW 4.8

I'm working on a project where we would like to add QGIS features to an existing Qt application. The Qt application has been built with Qt5.2.1 using MinGW 4.8 and thus I think I need to build QGIS ...
0
votes
1answer
35 views

QGIS 2.2: GDAL Grid (Interpolation) Error

As much as i understand Raster -> Analysis -> Raster (Interpolation) can provide me with a terrain file out of a shape file with a Z coordinate. I select the input and output file and a Z field. It ...
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0answers
31 views

back up of qgis file

Can we recover a previously saved version of qgis file? For example: I have saved my qgis file about an hour but I need the yesterday's back up of qgis file. The file which does contain today's saved ...
0
votes
3answers
40 views

How do I use QGIS 2.2 to plot some locations on a map (of the US by zip code)?

I am a newbie to QGIS. I just installed it on my MAC Airbook with Mavericks. How do I simply plot a few locations on a map of the US? All of the tutorials I can find on the web are for older ...
0
votes
1answer
42 views

Excel Nad83 table to gpx-Total noob

I have some waypoint locations that I have entered into a spread sheet in Nad83 the format of table looks like this NAME, -, -, UTM ZONE, Easting, Northing, -, Comment 1184236, 1, CP, 15, 451596, ...
1
vote
1answer
24 views

Including two different maps in one QGIS Print Composer

How do I use print composer in QGIS 2.0.1 to produce a final product with two different maps on the same sheet? I can't figure out how to use the 'add a map' button to add anything other than a ...
1
vote
0answers
47 views

How to get Drainage Divide and Streams from DTM

Does anyone know how you can get a map like this attached, having the digital terrain model? I'm sorry, but I do not know what is the exact technical term in English for them. I hope you understand ...
0
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0answers
29 views

Why do the SHP lines in QGIS Android look jagged (very simplified)?

I use QGIS for more than five years. I'm trying to make my way with QGIS Android for a while now. For some time I experience the following problem with the "nightly build" 2.0.1-Dufour: the SHP lines ...
1
vote
1answer
19 views

QGIS: Clipping a line layer using a polygon and getting an empty shapefile

I am using QGIS 2.2.0 and want to clip a line layer (roads) so that only those inside a polygon are shown. When I do this using Vector->Geoprocessing Tools->Clip I only get an empty shapefile as an ...
2
votes
0answers
22 views

Programmatically change layer position in the table of contents (QGIS)

I am trying move/position a layer to the bottom of the TOC by using addTopLevelItem on all other layers. I unsure how to reference the layers as QTreeWidgetItem's. def bg_bottom_level_item(self): ...
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votes
0answers
22 views

MODIS images set CRS and reproject

I am developing a plugin which reads MODIS images, and I know that MODIS images are in sinusoidal projection and I need to set that CRS and project the image to WGS84 (epsg 4326) in python. I search ...
0
votes
1answer
23 views

QGIS 2.2 - expression string builder to ignore NULL values

Simply put, I would like to create a rule-based filter whereby you add 2 columns together and you get a certain colour as a result. However, some fields in Column_1 may be NULL and those exact same ...
2
votes
2answers
29 views

loss of attribute data when copying between layers

I am trying to copy points from one layer to another in QGIS 2.2 The problem I get is that all the attribute data from the copied points is missing when copied onto the new layer, the columns show ...
0
votes
1answer
38 views

In QGIS are there similare construction tools to ArcGIS?

For a project we are using ArcGIS to reshape autogenerated features. For that we often use the construction tools polygon, rectangel, circle, etc in ArcGIS. The right angle is also an often used tool. ...