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

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6
votes
2answers
6k views

Create a polygon layer from point data

I'm currently using QGIS 1.8.0 I would like to create a polygon layer from a point dataset, where the size of the polygons relates to the resolution of the grid reference. The ultimate aim would be ...
4
votes
1answer
615 views

Is it possible to programmatically add calculated fields?

In the Memory provider described in PyQGIS Cookbook or in question How to create a new empty vector layer programmatically? I can see how to create a vector layer programmatically using standard ...
4
votes
1answer
1k views

How to zoom to point and place a pin?

Is there any means to combine the function of zoom to point and place a pin plugins in QGIS? Would it be possible to enter a xy co-ordinate and a pinpoint is placed at the point of the grid reference. ...
5
votes
3answers
2k views

Can I open ArcView 3 project files (*.APR) with Qgis? Is there a converter?

I would like to open files from an old ArcView 3.x project with Quantum GIS to work with the data. But this project data is saved as an APR-file, which I can not open with Quantum GIS. Is there any ...
5
votes
1answer
639 views

How to lock map labels for inset map in Print Composer?

OK, so I am making a print layout which has two maps, one an inset map with just a skeleton of a line layer and the other is the detail map at higher resolution. In the detail map, I want to show the ...
4
votes
2answers
495 views

Is there a way to load a kml raster super-overlay in QGIS?

I have created a set of tiled rasters as a super-overlay in Google Earth, and it performs remarkably well. Is there some way to load a super-overlay as a layer in QGIS? I am wondering if this could be ...
5
votes
3answers
612 views

Can I have Points, Lines and Polygon features in one QGIS layer?

I have a situation where planning is done on a "base map" consisting of rivers, contours, roads etc. There is a need to create a "overlay(s)" over the "base map" consisting of drawings, that could be ...
5
votes
1answer
1k views

How to automate the drawing of polygons (square) around a number of points in QGIS?

In QGIS (or alternatively any other scripting + GIS stack), how can I automate drawing a 100km x 100km square around a number of points, with the point being dead in the center? I'd need to loop ...
2
votes
1answer
327 views

Issue installing Qgis 1.8 Openlayers Plugin on Win XP

I recently installed Qgis on a Win XP PC. All seems fine. I went to install the Openlayers plugin using http://build.sourcepole.ch/qgis/plugins.xml and I get and error saying the plugins directory ...
2
votes
1answer
237 views

How extract data from SNODAS file?

I'm trying to extract data from a raster file from "Snow Data Assimilation System (SNODAS)" and convert it to a MMQGIS (plugin) grid layer (Hexagon) with QGIS. This raster file stores the snow depth ...
3
votes
1answer
517 views

Zoning and land lot map in QGIS

Our office is using QGIS to design zoning maps. Our maps display the zones in colors (area shapefile with "Zone" text attributes) and the parcels with a thin outline and the number as label (area ...
4
votes
1answer
532 views

How to start from scanned maps in qgis

What I have: A large TIFF covering parts of several contiguous sheets of the British OS 6 inch first edition. It has no georeferencing. It's just a series of scans which someone has stitched ...
3
votes
2answers
161 views

Connect QGIS to the custom application server

I'm new to QGIS and investigating how to migrate one home made GIS application on QGIS. The biggest difficulty for me now is to find the way how to plug QGIS to the application server that is being ...
2
votes
2answers
728 views

How to georeference a LANDSAT scene in QGIS 1.8?

I tried to georeference a LANDSAT scene in QGIS 1.8 but I failed. My first question is Can I use geografical coordinates as x,y coordinates of control points? or I need projected coordinates (from ...
2
votes
1answer
125 views

QGIS 1.8 map composition problem

I have recently installed QGIS 1.8 when I make a map with the adequate layer I switch to the map composition menu and try to insert a map in the white page. I draw the rectangle but nothing appears ...
2
votes
1answer
163 views

How to lock the legend in print composer?

I locked in the print composition (Druckzusammenstellung) the legend (attachment1). Then I saved the print composition and opened it (attachment2). But the locked legend is not locked? The changes ...
3
votes
2answers
2k views

How to upload polygon shapefiles to my GPS?

I used QGIS to create a table (*.shp) containing 3 polygons. These polygons represent "forbidden zones" that I would like to export to my Garmin GPSmap62st so once on the countryside, I'll can see my ...
12
votes
1answer
349 views

Open-source software for managing terabytes of different formats of geospatial data?

I have a problem that I am sure many GIS Teams or Departments have which is how to find, keep track of and manage multiple different datasets from multiple sources. I have read the responses from a ...
1
vote
1answer
203 views

run sql on Qgis

I want to do simple demo to our manager with quantum gis. i have buildings from my city with wgs84 projection on postgre sql database and also have non gis table which have who leaves this buildings ...
3
votes
1answer
219 views

Why can't I save my custom CRS?

I am unable to create custom CRSes in QGIS. The 'save' button doesn't seem to have any effect. My best guess is that I don't have permission to save in the folder or database where custom CRSes go. I ...
1
vote
2answers
536 views

Cannot get changeAttributeValues() to work in a loop

I'm trying to use QGIS to loop through a set of points, find their elevation from a DEM and use that value to update the point layer's attribute table. The loop works fine until I try to use ...
3
votes
1answer
2k views

Is it possible to increase/reduce features proportionally?

Is it possible with QGIS to increase or reduce features (polygons or lines already drawn) proportionally? Preventing me to redraw several times new polygons :) See picture above: Making it possible ...
5
votes
2answers
389 views

Can I load a country-size OSM file in QGIS?

I've tried several ways to display OSM data in QGIS, but none of them really worked well for me. For example, I've tried WMS layer, but when I try to print high resolution, it won't give me enough ...
1
vote
0answers
415 views

How to Sextante model builder within QGIS to convert KML to shapefile?

Are there any tutorials on how to use Sextante within QGIS? How I could use Sextante model builder in QGIS to convert KML to shapefile? This is a routine task and Sextante would really help. I am ...
3
votes
1answer
131 views

How to merge rasters with negative extents?

I'm trying to form a mosaic from two overlapping images of an old tithe map. I've used the georeferencer plugin using one of the images as canvas to generate a modified version of the other. I then ...
4
votes
3answers
243 views

Does QGIS have WMS-T (WMS with time) support?

Does anyone know if there's support for WMS-T in QGIS? Through the app I can add WMS layers, but I can't work with WMS-T (there's no place to set the time parameter). I been going through the the ...
5
votes
1answer
3k views

Importing KML in QGIS - what are all the node elements that QGIS looks for other than Name and Description?

Of all elements given at (ref: http://service.kmlvalidator.com/ets/ogc-kml/2.2/) only Name and Description seem to be recognized on importing KML using QGIS 1.8.0-Lisboa. I would like to know if this ...
1
vote
1answer
2k views

QGIS: creating lines from starting to arrival points?

Is it possible in QGIS to create lines from a table storing the X,Y-coordinates of starting and arrival points? So that a line.shp is automatically created? Or exists a plugin to achieve that? ...
5
votes
2answers
2k views

How to link to external files with relative path in QGIS actions?

Objective: I have point layers with attributes contain paths to external files (visio, autocad dwg...). I want to put them all in one folder together with the project file, compress the folder into a ...
4
votes
1answer
477 views

How can I reload a csv-file within qgis

I use Qgis to illustrate the results from my Matlab simulation. Matlab produces a csv-file which is connected to a shapefile within Qgis. At the moment I have to close and reopen Qgis to show the new ...
1
vote
1answer
323 views

How can I recalculate an attribute based on overlap with another layer?

I have 2 layers: The first one is a point Layer (converted from SRTM) with height information. The second one is a polygon layer (shows the forest). I want to reduce the height value - let's say ...
2
votes
2answers
665 views

How do I fix an error starting QGIS 1.8.0 on Windows XP?

I note that the installation of qgis completed successfully. However, the log procedure returns this message: "...... Estrazione: wvhpgn.gsb Estrazione: wyhpgn.gsb Cartella di destinazione: ...
3
votes
1answer
656 views

QGIS custom CRS for map of manufacturing shop floor

I'm working on a web app that shows a map of a manufacturing plant's shop floor. I've built it in Inkscape and QGIS, but when I try to load it into Tilemill, I get a CRS error. Specifically, it ...
2
votes
2answers
270 views

Why does the map legend not update in print composer?

I'm having trouble with the QGIS map composer: If I change the map in QGIS and reopen the map composer and click on update, the legend elements DON'T update! For example: Before one certain country ...
6
votes
3answers
2k views

How do I get the path of a project, or layer file in PyQGIS?

I am generating new raster files from vector layers on a project. I would like to save them in the same directory as the project or layer files. How do I find this path using PyQGIS?
0
votes
0answers
43 views

Only one row displayed when opening attribut table

When running the example data for Alaska, the attribute table view for Lakes only shows the first row. All lakes are displayed in the map view.
0
votes
1answer
301 views

How to debug QGIS installation problems on XP? [closed]

I'm installing Qgis (Standalone 1.8) on all the PCs of the town planning office where I work. All good for 4 computers, on the fifth installation does not work. Computers have all XP with SP3. In ...
4
votes
2answers
1k views

Create custom projection using either QGIS (or ArcGIS Desktop)?

I have searched for an answer to this but don't see anything relating to what I am trying to do. What I have are a series of Geographic Coordinates, Latitude, Longitude, Ellipsoid heights. What I ...
1
vote
1answer
169 views

QGIS python plugin, segmentation fault, what can I do?

I'm trying to write a python plugin to create an input file for an urban climate model out of three shape files. Unfortunatelly QGIS closes when I try to load the plugin. When I start QGIS from the ...
2
votes
2answers
2k views

How to create a map with states by attribute value?

I'm using Qgis, but I am quite familiar with R and python. So I could use any of these. I want a map of mexico but want to color the stats according to a certain variable. It goes from 0 to 100. So ...
2
votes
2answers
452 views

How to identify image footprints of an aerial photograph

I need a tool that will take aerial images with Lat, Long, and Alt in their EXIF data and produce foot prints of the images. We need to verify that the images cover the photographed area with proper ...
11
votes
2answers
6k views

How to check Topology in QGIS?

I have two Shapefiles with Polygons ( City and Forerst) Is there a Plugin who is able check the topology (QGIS)? Like "Knots do not overlap" or something like that? I dont want that they overlap. ...
7
votes
3answers
3k views

Loading geotiffs into PostGIS using raster2pgsql

I have an issue with loading some Ordnance Survey raster data into PostGIS. I have been using the following raster2pgsql command to load a tif that I have placed in my C:\Program ...
3
votes
2answers
842 views

How to densify a polyline according to a specific length? [duplicate]

Possible Duplicate: Add vertices to lines I am using QGis 1.8.0 I would like to densify a polilyne according to a particular length of segment (ex. 200 m). I know it is possible with other ...
5
votes
1answer
640 views

Create point between two points with given distance or length

What I have: Coordinates of Point A and Point C and therefore vector and azimuth from A to C What I want: Coordinates of Point B (between A and C) with a distance from A to B of 35.2 meters. ...
3
votes
2answers
416 views

Looking for qml specification

Where I can find qml specification which is used for store symbology information in QGIS? Try to googe it - no result.
0
votes
1answer
1k views

Ogr2Ogr doesn't work with QGIS 1.8

I'm trying to use Ogr2Ogr.exe to import some shapefiles. It came installed with QGIS 1.8. When I try and run it, i get the following error: C:\Program Files (x86)\Quantum GIS Lisboa\bin>ogr2ogr ...
7
votes
2answers
10k views

How do I change the data type in attribute table in QGIS

I have county data in which the FIPs (actually State FIPS and County FIPS combined). I have data imported as CSV with the sames FIPS data titled STCounty. However, the shapefile FIPS is listed as a ...
4
votes
1answer
4k views

What's the proper format for WKT linestrings when importing into QGIS?

I'm trying to run the following test CSV through the Delimited Text plugin as WKT data: oid,Line 1,LINESTRING((45.554194 -122.686101, 45.433001 -122.762632)) 2,LINESTRING((45.432505 -122.598327, ...
2
votes
1answer
244 views

How can I add individual geoprocessing tool, for e.g. buffer onto the toolbar in qgis?

I am no programmer so I do not understand how to create a plugin to add a button to the toolbar. Is there another simpler way to do so? I only need a few tools from the ftools suite and do not want ...