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

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4
votes
2answers
583 views

Looking for a functionality in QGIS to find all neigbours in a polygon layer

I am looking for a functionality in QGIS to find all neigbours for each polygon in a polygon layer. The result should be a table with 2 ID-Columns: one for the polygon and the second for the ...
4
votes
2answers
932 views

How do I split polygons into line segments?

How can I split my polygon file into "segements"? The lines should be broken up like this picture shows:
2
votes
3answers
553 views

Is there any way to reproject multiple layers in QGIS?

I'd like to be able to consolidate not only the layers of a QGIS project (using QConsolidate) but also the projections used by each layer. On-the-fly projection reduces performance in QGIS, and this ...
3
votes
1answer
593 views

Is it possible to set the project CRS via a Python command?

Is it possible to set the project CRS of an project in QGIS via a Python command? In my case the user should open QGIS, start my written plugin and this plugin will load spatial data which has the ...
3
votes
2answers
653 views

How to join lines in QGIS for later using “lines to poly”?

After successfully merging lines (using snapping) with merge_selected_features i got nice result - one merged line. Next thing was to make polygon from created merged line. Result is not nice - it ...
10
votes
1answer
402 views

Is there a way to add system date in print composer?

Is there a way in the Print Composer of QGIS to create a label that will automatically update the date (systems date) instead of having a label that you have to manually have to update?
7
votes
3answers
2k views

How to create a new Spatialite database in QGIS

I've been trying to create a new spatialite database within QGIS 1.8 (SpatiaLite Version 3.0.1; QSpatialite 6.0.3) and keep getting this error: "The SQL query seems to be invalid. no such table: ...
15
votes
8answers
12k views

Can QGIS open KMZ files?

I know I can add KML files once I have unzipped the KMZ files, but is there a way to open KMZ files directly? When I try to open a kmz file on QGIS 1.8.0 on Windows XP, through the all files filter, ...
2
votes
0answers
391 views

Is it acceptable to store OSGB36 data as geometry in SQL Server?

I've set myself a project of getting some geo data into SQL Server but before I get started doing any of the big jobs I wanted to see if I was on the right track. All of my data is for the UK and is ...
1
vote
1answer
320 views

How can I convert my scale bar from milimetres/ degree into metres or kilometres using QGis?

I am making a map in print composer. I am trying to add the scale bar and it's appearing as a box with a zero digit inside it. What should I do to make it display properly?
4
votes
1answer
597 views

Is it possible to create a point within a Polygon (not a centroid)?

Is it possible (without writing Python code - sorry I'm not a developer) to create a point layer from a polygon layer but ensure the point is within the polygon? The ftools centroid tool is cool but ...
2
votes
2answers
126 views

Why does exporting labels with buffers take so long?

I set white borders for text (city names) in qgis. If I export the map without white borders it exports quite quickly (png 600 dpi). If I set the white borders it takes hours! Is there any way I can ...
2
votes
1answer
250 views

Shouldn't QGIS read the proj definitions from the spatial_ref_sys table?

I have serveral layers in PostGis that use a custom projection. I added the projection SRID and it's deffinition to the spatial_ref_sys table but, when I load the layer in QGis, I get the "Coordinate ...
1
vote
1answer
341 views

Is it possible to edit Delimited Text Layers in QGIS?

GIS beginner here... I have a tab-delimited text file that I'm importing into QGIS just fine. But I try to edit the attribute table, the little pencil-looking button is grayed out, and it's not ...
2
votes
1answer
431 views

How to manage null values in QGIS

I made a merge of several AsterGdem blocks near Egypt and Israel. I have portions of the Dead and Mediterranean Seas. Since near Galilea elevations are below sea level this makes the following problem ...
10
votes
1answer
790 views

Is it possible to take automatically a “screenshot” of my selected feature in QGIS using Python?

I am implementing a tool which allows the user to create a profile of a feature (in my case urban parcels). Is it possible to automatically take a screenshot of this feature (displayed in a QGIS ...
2
votes
3answers
2k views

Convert coordinates to geometry (polygon) using QGIS

I have an Excel sheet with grid data including geographical coordinates. I know that the coordinates represent areas, i.e., a multi(polygon). However, the data lacks geometry information. I'm looking ...
0
votes
1answer
280 views

python qgis.core import error caused by spatialite libraries

I have an error when trying to import qgis.core to python: >>> import qgis.core Traceback (most recent call last): File "<stdin>", line 1, in <module> ImportError: ...
4
votes
3answers
356 views

Why does the layer list context menu not open anymore?

I cannot access layers properties (i.e. change color, filter by query, anything). The mouse right click doesn't do anything. Is there a way restoring qgis to default? Ubuntu 12.04, QGIS 1.8
1
vote
1answer
421 views

Is it possible to convert a Geoserver SLD to Quantum QML format?

I have a web application which runs on Geoserver. I am migrating my application to desktop and am struck at applying the same color schemes and symbology. I am not able to find a way to convert SLDs ...
4
votes
2answers
2k views

Does OSGeo4W install a 32 bit or 64 bit version of QGIS?

I just want to know if you are installing Qgis via OSGeo installer on a windows 64 bits OS (XP, vista or 7) Does it install a 32 bits or 64 bits version of QGIS? Usually the stand alone installer ...
2
votes
4answers
1k views

Qgis: How to display special characters German “ÄÜÖß” in a Map?

I have a shape file with names for Regions. These don't seem to contain special characters but ugly hyroglyphes. What can I do do display them correctly. If I import the shape as UTF-8 it doesn't ...
0
votes
2answers
235 views

Why doesn't QGIS accept my manually altered geospatial column?

I have a table with a geospatial column with srid 28992 but noticed that if i try to show it in QGIS (v1.9) on any openlayer map (through the OpenLayers plugin) it is off by a few hundred meters. ...
0
votes
1answer
148 views

QGis : superimpose 2 rasters georeferenced (adjustment)

I am pretty new in QGis and I encounter the following problem. I have 2 rasters, let's say, "cadaster" and "tranchot". The raster "tranchot" was georeferenced from the raster "cadaster" with QGis. ...
6
votes
1answer
333 views

How to generate non-merging buffers in QGIS?

I'm using QGIS to construct some fixed width buffers from a coastline shapefile. Is there a way to easily handle overlaps/ median lines? (I'm not sure if there's a particular term or phrase I should ...
-1
votes
1answer
3k views

Opening TIFF DEMs in QGIS

I have files, in Tiff format, downloaded from ASTER-GDEM. Can I open this file with QGIS? If yes, how? Thanks in advance
2
votes
1answer
1k views

pyqgis: How to get features of selected geometries

I wonder if anybody could provide an example how to get the attributes of selected Features? I tried the folowing Code in the python Console - but I'm stuck at the point where I'd like to get the ...
2
votes
1answer
135 views

Color depending on attribute

I'm trying to set the color of a vectorlayer feature depending on the feature attributes with PyQGIS. How do you acces the attributes of a vectorlayer feature?
0
votes
1answer
225 views

Edit multiple tables with the same structure at the same time?

does anyone know how to edit multiple tables at the same time? I have multiple .tab files and I want to change the order of the fields. Is there any way to do this for all of them at once. They all ...
3
votes
3answers
1k views

How to digitize polygons from georeferenced raster file

I used QGIS to georeference a raster file of a custom US map. The map has features which are not strictly defined by state borders. I would like to digitize the map by creating contiguous borders for ...
1
vote
1answer
2k views

How to export Symbology from ArcGIS to Microstation or QGIS?

I am using ArcGIS 10.1 and trying to figure out how to export my symbols of elements in ArcGIS to CAD or QGis readable format. Problem is, that I can only export symbology to Style, or export map to ...
1
vote
2answers
2k views

Clean way to install gdaltools plugin for QGIS on OSX

I have qgis 1.8.0 on osx mountain lion and am installing the gdaltools 1.2.29. I have run into a problem that a number of people are seeing. The plugin cannot find my gdal python (see below). ...
1
vote
1answer
174 views

what raster format for r.los in qgis

What raster format should I use to create viewsheds in QGIS using the grass r.los plugin? I am using the Ordnance Survey Opendata DTM (tried both ascii and shapefile formats) and srtm geotiffs but ...
0
votes
1answer
307 views

How to save bookmarks with names?

When I create a bookmark the name and project that I enter are not saved when I click Close. The manual says there should be an OK button but there isn't. Using QGIS 1.8 thanks!
0
votes
2answers
506 views

Primary key field hidden on attribute table added to QGIS

I'm having the following issue with QGIS. Adding a sqlite text table (Layer > Add Vector Table) QGIS hides the primary key field (having name id). I understand also QGIS uses this field as unique id, ...
0
votes
1answer
462 views

How to insert images in print composer?

I do not seem to be able to paste an image from mac i photo to QGIS print composer. When i click on add image I get a blank box with no photo. Also when I click to add a label I do not seem to be ...
1
vote
1answer
124 views

QGIS systematically guesses wrong CRS

QGIS (1.7) systematically applies the wrong CRS when adding layers (or shapefiles from a given lot). They should be NAD83__MTM9 (EPSG:32189), as can be inferred from the prj-file, but the ...
1
vote
0answers
401 views

Does QGIS read NAS data?

I wonder if it is possible to load German NAS-Data into QGis or to convert them to Shapefiles. I'm using QGIS 1.8 on Ubuntu 12.04. Thanks I'm sorry, I thought I did - NAS is the new ...
3
votes
2answers
246 views

Is there a Legend Limiter in QGIS?

Is there in QGIS a function or a plugin that works similar to Legend Limiter in ArcGIS? The attribute I want to show in my legend has many possible values, I want my legend to only show those values ...
0
votes
0answers
153 views

QGIS 1.8 problem with rendering polygons in WGS84 on Ubuntu 12.04

I'm using QGIS 1.8 on Ubuntu 12.04. If I add a polygon layer in SHP format and WGS84 projection and start to zoom in, from a scale of 1:200.000 aprox. polygons on the edges are not drawn anymore and ...
2
votes
1answer
242 views

Is there an itemSelectionChanged Signal in Attribute Table?

The QgsVectorLayer class emits a selectionChanged() signal . If a QGIS user for example selects a record in the Attribute Table of a Vector Layer - a selectionChanged() signal is emitted an can be ...
5
votes
5answers
1k views

How to generalize and vectorize a LandUseClassification raster file?

I want to vectorize that rasterfile with its 6 landuse classes. The classification is very noisy and have to be generalized before. The result should be a polygone vector file. I use SAGA, (GRASS) ...
14
votes
5answers
1k views

Find pseudo nodes in free GIS software

Software gvSIG OA Digital Edition 2010 have tools topology for finding pseudo nodes in linear geometry. I set cluster tolerance 0.00002 and maximum number of errors -10000 for 20000 link count linear ...
2
votes
0answers
267 views

Setup of development environment of QGIS on windows with qt creator

Can anyone help me in setting up environment for working on QGIS on windows using qt-creator? I am using qt creator version 1.3.1,qt version 4.6 and QGIS version 1.8. Thanks.
4
votes
3answers
3k views

How to convert the file with projections in meters to Lat-Long in QGIS ar Erdas Imagine?

I have file in Lambert Conformal comic formate for the data of Australia, Its cordinates are in meters. I want to convert it into the Lat-Long system. Which Projection, Spheroid and Datum I should be ...
1
vote
2answers
990 views

shape file coordinate system

I added a shape file of Iran to Qgis. 'Tehran' has 35.6833° N, 51.4167° E coordiantes, however Qgis shows Tehran with 4772860,31296767. How i can view coordinates of a city or location in latitude ...
3
votes
2answers
2k views

How to change position of columns in attribute table?

If I have an attribute table with columns A B C D, is it possible to move the columns to different positions, say, B C A D? When making a new column with the field calculator it would be useful to put ...
2
votes
1answer
365 views

Could not commit changes to layer X

I am editing a layer's (Z) attribute table. I made some columns, used the field calculator to fill them up, made some more, went back and deleted some and then tried to save the edits and got the ...
4
votes
7answers
3k views

How to get OS Mastermap data into QGIS?

I have been tasked with getting OS Mastermap topography data into QGIS system to compliment our other map layers. The data comes in .gz format. Which I am told needs to be decompressed before I can do ...
1
vote
1answer
572 views

Openlayers Overview and OpenLayers versions

I have installed OpenLayers and the Openlayers Overview plug-ins but I am not sure if they are working. I can create new 'open' layers from the Openlayers plug-in drop down, but when I try to add a ...