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

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5
votes
3answers
1k views

How to produce a singlepart featureclass with unique IDs for each spatially non-connected polygon?

What is the best method to convert a singlepart shapefile (i.e. one record that contains several non-connected polygons) into a mutlipart shapefile? --EDIT For clarification the original question ...
3
votes
1answer
86 views

How to exactly copy one installation to another PC?

I've installed qgis on one workstation using OSGeo4w. I've launched the installer from a local folder and I have downloaded source files on a remote mapped drive. Frequently I relaunch OSGeo4w to ...
3
votes
0answers
395 views

How to set up a QGIS project in MVS 2008?

I have built QGIS using Visual Studio 2008. I would now like to start using the QGIS API for Windows Development. Of course I have Qt installed on Studio I hope correctly. I am new to Visual Studio ...
3
votes
1answer
347 views

How to open a Spatialite non-spatial view in QGIS

I'm using Qgis 1.8.0, and spatialite 2.3 in a Windows Vista machine. I have a database in Spatialite, and I have created a view from one of its tables. When I open it in QGIS, using add Spatialite ...
1
vote
1answer
331 views

How to draw lines for diagrams?

Just before submitting bug: in Diagrams, there is possibility to use Position AroundPoint or OverPoint. Whatever I choose Line Options selection stays gray: I can't choose any line. So, I suggest ...
1
vote
1answer
211 views

It is possible to add A* to the pgrouting plug-in?

I am using pgrouting layer plug-in as described in this post: http://underdark.wordpress.com/2011/12/18/osm2po-part-2-pgrouting-on-osm-the-easy-way/ I am now able to calculate the shortest path using ...
1
vote
1answer
355 views

QGIS error when open project when layer via accesses the database

I changed from QGIS 1.7.3 to 1.8.0. Problem is that I can´t open QGIS Projects, QGIS crashes when there are layers involved loaded via access-database connection. I used eVis. What can I do?
1
vote
1answer
136 views

QGIS Crashing in Ubuntu / 'Save As' browsing

When trying to create a new shapefile in QGIS on Ubuntu, I get a crash whenever I browse to a folder to save the file. Has anyone else experienced this?
0
votes
1answer
287 views

Is there a limit for how many layers can be put into a group?

I am Running QGIS Lisboa 1.8.0 on a MacBook Pro. I have several vector layers with similar information which clutter the Layers panel. I created a group to put them in but when I drag and drop the ...
3
votes
3answers
896 views

How to speed up Postgis raster layer display in QGIS?

i've been importing some digital orthophoto geotif files into postgis 2.0.1 via raster2pgsql tool (i also made 3 levels of an overview table - pyramid). Then i tried to import the layer into qgis via ...
4
votes
1answer
114 views

Is it possible to edit a layer in QGIS while there is an active query?

I am new to Quantum and I am digitizing polygon layers using the editing features. I would like to apply simple queries ('date > 2012/08/01'), however while the query is active I cannot edit the ...
1
vote
0answers
354 views

Why is there a shift between OpenLayers and vector layer in print?

Sorry for my poor english. I'm a very recent user of QGIS (QGIS 1.8; ubuntu 12.04). Does anybody knows why the .tif or .jpeg or .pdf files I generate with the QGIS composer have different layers ...
11
votes
3answers
3k views

Is there a way to use “Select by Attribute” in QGIS using a python command?

is there a way to use the function "Select by Attribute" in QGIS using a python command? In my plugin the user should enter a value via a GUI and this value should be used in a function which selects ...
2
votes
0answers
209 views

How would I modify GPS tracker to accept two nmea inputs and gpsmarker to include a heading vector?

I use QGIS on a research vessel and wonder whether I could modify the QGIS 1.8.0 gpsinformation widget. I want to achieve two things. 1. Change the GPS marker to a boat shape which points in the ...
2
votes
8answers
6k views

How to convert from dgn to shp or dwg files?

I am a frequent recipient of microstation dgn files and don't like it because I don't have software to convert it to autocad. I do have ARCVIEW, but I can't edit the files. I have tried other open ...
2
votes
1answer
1k views

QGIS 1.8 not loading after install

I have just installed QGIS 1.8 on Windows 7. Once the install completed and I tried to open QGIS (via the desktop icon) nothing happened. I had this issue when installing QGIS 1.7. I was able to ...
4
votes
2answers
329 views

Is it possible to add a new line in a non-spatial table using Qgis?

While using QGIS, and having loaded a non spatial table (from a dbf or a Spatialite table), is it possible to add a new row to its table attributes? Normally in a spatial layer you have to use "add ...
2
votes
2answers
451 views

Mac OS 10.7 QGIS 1.8 Desktop Install Problem

I've downloaded QGIS-1.8.0-2.dmg and the required GDAL Complete 1.9 framework package and GSL framework. The frameworks are installed; however, when I try to start the installation of ...
6
votes
3answers
2k views

Is there a way to count the number of vertices of polygons and lines?

In QGIS, is there a way to count the number of vertices of polygons and lines in a given layer, and create a separate field containing these values? I suspect it's a function somewhere in the field ...
1
vote
1answer
72 views

Why does Delimited Text Plugin display red sample columns?

When importing a CSV file (with associated CSVT) using the Add Delimited Text Layer feature, sometimes the preview window displays a column of sample text in a red font. Does anyone know the reason ...
2
votes
2answers
2k views

Is it possible to extract Coordinates of Polygon Centroid in QGIS?

I have created polygon centroids using one of the "Geometry Tools" but I would like to extract the actual coordinates into Excel for further work. Is this possible?
0
votes
0answers
185 views

QGIS Invalid Data Source in raster calculator

I just installed QGIS and am new to it. I want to use the raster calculator, but after assigning a name to the output layer QGIS tells me "Invalid Data Source" and "filename.tif is not a valid or ...
9
votes
2answers
2k views

How to remove the border of a symbol?

I have a point layer in QGIS. I have created a graduated color scheme, but it doesn't look good because the border of all the symbols is showing and are overlapping (so you hardly see the color of the ...
7
votes
6answers
5k views

Rasterfile clipping error: Cannot compute bounding box of cutline

I have a raster file and want to clip it, a vector file is supposed to be the mask layer. I use the most obvious method (Raster->Extraction->Clipper). No matter what I do, I get this error (see pic): ...
0
votes
1answer
379 views

Is it possible to rotate items in QGIS Print Composer?

Is it possible to rotate items in Quantum GIS Print Composer? I just didn't found and before submit feature demand just double-check this. Pekka
4
votes
2answers
3k views

How to display both scalebar in kilometers and grid in lat/long degrees in Quantum GIS 1.8 Composer?

Also, how to display both scalebar in kilometers and both lat/long degrees and northings/eastings in QGIS 1.8 Composer? Layer is projected to UTM. Thank you.
0
votes
1answer
261 views

How to import multiple textfiles in one step

Is ist possible to import multiple textfiles (csv, tsv etc.) as layers in one step or do i have to do it file by file?
3
votes
1answer
1k views

Using Qgis server with Ubuntu 12.04

I realise there had been many posts on this subject but unfortunately I need to post again. I've been banging my head against this all day. I'm trying to get qgis server working with Ubuntu 12.04 ...
2
votes
0answers
300 views

Can hdf4 images be used in QGIS?

I'm trying to use hdf4 raster image in QGis 1.8. This image come from the MODIS satellite. I've loaded the file, it appears on the layer window bu it is impossible to see it on the display window. ...
10
votes
1answer
580 views

Is there a detailed description on the .qgs file structure somewhere?

Is there a detailed description on the .qgs file structure somewhere? I checked here: http://mrcc.com/qgis.dtd ("The requested URL /qgis.dtd was not found on this server.") and here- ...
1
vote
1answer
175 views

QGIS Crashes when writing to PDF

8 Lisboa. I have a very large mapper. Formatted to A1 size with a large area and constraints laid across it. Everytime i try to write to pdf it crashes. It is just due to the size of the file. I ...
7
votes
2answers
197 views

How to use Python modules as data providers in QGIS?

I don't know if it has been discussed in the past. Qgis data providers can only load native compiled libraries (.so, .dll, etc) that offer the required interface. Is there anything blocking to the ...
2
votes
2answers
2k views

Is there a way to automatically populate attribute values in Qgis?

We are using a Qgis/PostGis combo, where Qgis is used for adding features with attributes into a PostGis database. Is there a way to automatically fill the attribute data values with some ...
3
votes
1answer
3k views

How to reference to my in QT designer created buttons in python?

I have created an own QDialog (using QT Designer) with three push buttons. The names are pButton1, pButton2 and pButton3. After saving the file I created the ui file by using: pyuic4 ui_xy.ui > ...
0
votes
1answer
120 views

Why are grid and scalebar measures 1mm too long in a 1:10000 print?

I used qgis 1.8 to compose a map from the WMS-service of the Belgian NGI. I added a scalebar and grid to it. When I measure it by hand, the distance between the longitudelines is 101mm instead of ...
3
votes
2answers
2k views

How to convert a point grid to a raster?

If I load the original .csv file, I then have a map of the African continent represented by 14069 data points covering it at 40x40km resolution. Each data point shows solar radiation means across the ...
2
votes
2answers
216 views

Reducing a 100Km OS Map to usable size

I have downloaded a 100Km map from OS, but the problem is that it is far larger than I need and hence takes a long time to load every refresh in QGIS. Is there a way to cut down the size of the ...
8
votes
2answers
2k views

How to smooth large vector polygons from Raster

I have a landuse classification raster file (6 classes) of a large area. But I need it in vector polygons so I vectorised it. No problem so far, but the result is - of course - that every pixel is ...
4
votes
2answers
629 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
999 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
640 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
2answers
652 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
689 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
473 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
3k 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
14k 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
408 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
325 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
654 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
127 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 ...