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

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1answer
335 views

How to convert images from the South African co-ordinate system to WGS84 lat/long?

I have a number of orthophotos for an area in South Africa, but they are projected in the South African co-ordinate system which measures a location in meters from a central (uneven) meridian. These ...
4
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3answers
1k views

What's the easiest way (style wise) to publish my MapInfo map as WMS?

I've downloaded data for my country from OSM and let a GIS expert to style it for me in MapInfo pro. (I have TAB files and .wor - workspace). When I tried converting them to SHP (for QGIS) I've ...
3
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1answer
123 views

Points warped when exporting to shape

I have recently purchased a Trimble GeoXH (used) and have done a few surveys. I have done differential correction in Trimble Pathfinder Office and all points seem fine. When exporting to shape and ...
2
votes
1answer
1k views

How to get attributes of overlaying polygon layers by a spatial query?

I am new to QGIS and would like to merge selected data/attributes out of the attribute tables from overlaying vector objects on different vector layers without creating new additional layers. Is ...
2
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0answers
171 views

How can I map polygon value distribution?

I'm surveying an area and have a z-value attached to each polygon. In comparison to the area I'm studying the polygons are quite small. What I'm trying to do is show the distribution of this value. ...
1
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1answer
235 views

Merging data in Quantum GIS

I have a set of postcode boundary data that currently goes down to the most detailed level possible, like this: AB1 2CD I would like to 'simplify' the data so that it just shows the first part of ...
13
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3answers
785 views

Why Do Colors Look Darker When Printed on Paper?

I made a map with a terrain-colored relief-shading in the background. I then exported them as PDF from Print Composer in QGIS. But when I print the PDF onto paper: the shaded-relief color in the ...
5
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1answer
525 views

How to emulate a specific vector grid in QGIS?

I would like to analyze data included in a pdf file. The file contains information on characteristics of 16km grid cells for a specific study area. The file also includes a map displaying the grid. I ...
0
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1answer
706 views

How to fix crashes after update to Ubuntu 12.04?

Some weeks ago I had updated Ubuntu at the 11.10 version, but I had started having problems with QGIS 1.8: I installed the program and launched it, but it didn't open and crashed continuously. I ...
1
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0answers
207 views

How does QGIS execute Python plugins?

I am trying to run a python script from within a python plugin. The script runs a CGIHTTPServer in a separate thread. It works as expected when executed from the command line and i can issue requests ...
2
votes
2answers
413 views

How to import qgis.core to python IDLE?

I try to follow the step in How to import qgis.core to python app? to import qgis.core with Python Shell. But when I type set PYTHONPATH=C:\Program Files (x86)\Quantum GIS Wroclaw\apps\qgis\bin it ...
2
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2answers
446 views

How to create a “Datum-less” projection in QGIS?

I want to use QGIS to do some georeferencing and image registration. On ArcMap10 I can define an "Unknown Projection", basically a default metric grid, and use it as a grid for georeferncing. In QGIS ...
6
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1answer
361 views

Generalize large polygon-file

I have a large polygone file with landuse information (6 classes). Its vectorised from a raster classification so the polygons are all angular. Any of my tries to generalize with v.generalize (sneaks, ...
0
votes
1answer
292 views

QGIS Crashes when selecting > Settings>Project Properties

I am new to QGIS and this forum but have not found a related problem with a solution. Running Quantum GIS 1.8.0, on Windows 7 Pro Running the software, the first action I would normally take on a ...
2
votes
1answer
221 views

How to align labels using Label toolbar?

I'm worried I'm missing something terribly obvious here: how do you set the alignment (left / centre / right) for feature labels? I'm referring to QGIS 1.8, and using the 'Label' toolbar, rather than ...
9
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2answers
1k views

What to do with -3.4e+38 nodata values?

I am trying to process some bioclimatic raster files, such as can be downloaded from http://www.worldclim.org/current (bioclim set). They seem to have nodata values set to -3.4e+38 according to QGIS ...
4
votes
2answers
270 views

Why are “capture line” etc not available?

I have a question about QGIS which I just started using. I loaded a shp file and want to edit different elements, but the tool for drawing a new line or adding new points does not appear. I can add a ...
2
votes
1answer
196 views

Why shapefile loaded in canvas always appear in random color?

I created the simple frame .UI file, compiled with pyuic4, and tried the ShapeViewer.py to load the shapefile "world_borders.shp". However, the map is always loaded in different random colors every ...
1
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1answer
240 views

QGIS Python error on OS X while trying to simplify shapefile geometries

I am trying to reduce the file size of the shapefile by simplifying geometry in QGiS on OS X. But I get the following error... An error has occured while executing Python code: Traceback (most ...
3
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2answers
311 views

How to generalize polygon attributes in a regular polygon grid?

I'm trying to generalize the attributes of a set of polygons(let's say they're census blocks with a population property) into another, overlapping set of polygons(let's say it's just a grid with no ...
1
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0answers
30 views

qgis projections from Michigan's CGI data [duplicate]

Possible Duplicate: How to reproject from Michigan Georef to WGS84 in QGIS? I'm importing shapefiles into QGIS. These files were created by the state of Michigan, primarily to be used in ...
2
votes
1answer
2k views

How to fix missing ippj-5.3.dll error in QGIS?

I try to install OSGeo4W but when I tried to run it appeared an error message about ippj-5.3.dll is missing... does anyone know what happen?
2
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1answer
279 views

Warning: QNetworkDiskCache::prepare() unable to open temporary file

When I run qgis 1.8.0 on Linux and load a WMS layer from a remote server I get messages (in terminal) saying Warning: QNetworkDiskCache::prepare() unable to open temporary file Downloading tiles ...
2
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0answers
134 views

How to geocorrect in qgis?

I need to fit a utm wgs84 tiff raster to a topomap in the same projection. I use GCP and it invariably fails. The first raster uncorrected rater superimpose well, the "geocorrected" raster is ...
4
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1answer
298 views

How to add a geometry to an existing feature that was created with NULL geometry?

I have a simple SpatiaLite geodb loaded in QGIS with one table. There is a POINT geometry field and some alphanumeric data. In some cases I can record data about a specific site, but the coordinates ...
2
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1answer
2k views

Using clip tool in qgis - contours to exact map area

I am using QGIS. I am trying to clip contours and water vector layers to the exact size of my map (polygon layer). Sometimes it works; sometimes the program crashes before completion (at the same ...
3
votes
1answer
341 views

How to use scale -rule based renderer in QGIS?

I wish to render a shapefile of builindings such that at scales below 1:5000, they have a border, and above 1:5000, they do not have a border. For this, I went into layer properties, selected ...
7
votes
2answers
120 views

How do you obtain the execution times of processes in qgis?

I am working on QGIS. I need to determine how much time QGIS needed to finish a specific task. I have been unable to get execution times for the processes. What is the proper way to get processing ...
1
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0answers
22 views

Retaining original thematic colors in a USA source shapefile [duplicate]

Possible Duplicate: Adding Layerfiles (.lyr) to Qgis New to QGIS and need a lot of help! I am using QGIS with MAC - I have downloaded a USA thematic map but when I open it in my system it ...
3
votes
1answer
244 views

Labels with white (or other color) background

I tried to give my labels somekind of box and a backgroundcolor (or boxcolor) in QGIS, but i couldnt find the right option. My labels are not readable because my layers are too dark. I found offset ...
4
votes
3answers
2k views

How to style points in QGIS based on multiple attributes

While trying to find a useful way having earthquakes displayed, I noticed that it isn't that easy to manage. I'd like to be able to recognize the "Magnitude", "Date", and "Depth" from the style of ...
3
votes
2answers
464 views

How to create a standard deviation map from three rasters in QGIS?

I have 3 normalised (0-100) raster maps. Is it possible to get a map which shows the standard deviation? I'd like to see the areas with smaller and higher std deviation. Thank you!
3
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1answer
683 views

How to remove a vector QgsVectorLayer from QGis python plugin

I managed to add QgsVectorLayer in QGIS through a python plugin, for example: vl = self.iface.addVectorLayer(uri.uri(), layerName, self.dbConn.getProviderName()) But how can I remove it?
2
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0answers
11 views

updatation query along a point [duplicate]

Possible Duplicate: GIS QUERY on point and buffer All, I have a PostGIS/Postgresql DB that has one table in it. One with point geometries and the other that represents buffer as polygons. ...
2
votes
1answer
740 views

How can I fix QGIS PostGIS Manager error 'shp2pgsql' is not recognized?

I have QGIS 1.8.0 installed via OSGeo Installer and work on win 7. All I need is to upload the shapefile to the database via this plugin. Unfortunately I am receiving an error: Something's wrong: ...
4
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3answers
97 views

GIS QUERY on point and buffer

I have a point table and the buffer geometry is created around the point. I have defined the if the point is within the buffer_distance then its value is =1 and if it is outside the buffer its value ...
0
votes
1answer
477 views

How to improve OSM layer resolution in OpenLayers plugin while exporting?

I'm having trouble with the OpenLayers Plugin exporting a map to a png or pdf file: The output resolution of the exported osm-layer is very, very poor. Zooming to 100% in the png file shows big ...
2
votes
1answer
105 views

Error message 'Module qgis.v.kernel.rast.py not found'

How do I repair this error in QGIS: The error message was received whilst trying to run v.kernel from the modules list. I can however run v.kernel from the GRASS shell. A while ago, I installed ...
0
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0answers
42 views

Point to Polygon [duplicate]

Possible Duplicate: Create new polygon layers from postcodes latitude & longitude I'm running QGIS 1.8.0 I have a list of points that I need to convert to one polygon. So far I have ...
0
votes
1answer
725 views

Transform Shapefile from WGS84 to NAD83 using QGIS? [duplicate]

Possible Duplicate: How to reproject a vector layer in QGIS? I have some shapefiles whose CRS is WGS 1984 and I have some shapefiles whose CRS is NAD 1983 State Plane Illinois East. I want ...
6
votes
2answers
1k views

How to compile QGIS with GRASS on Ubuntu?

I am on Ubuntu building qgis with grass plugin. I have build grass code separately and used --prefix to provide the path GRASS_PREFIX is /usr/local/grass-6.4.2 and GRASS_INCLUDE_DIR is ...
4
votes
1answer
139 views

Problem opening a shp in another application

I helped a colleague converting waypoints from a gpx file to a shape file. My colleague has only arcMap. I gave him the shp and when he opened it in ArcMap, it did not show anything in the attribute ...
5
votes
1answer
71 views

Geographic locators within Polygons

I have a list of geographic locators and a boundary file. In QGIS, is there any way merging them together to create a lookup saying this boundary contains these locators? Not the number the actual ...
7
votes
1answer
225 views

Why is QGIS 1.8 crashing when exporting to PDF?

I want to export for example this: but qgis crashes. Sometimes with an error message std::bad_alloc. But: My Mac has 8 GByte RAM and "just" 5,... something (of 8) GByte are used, moreover there is ...
6
votes
3answers
1k views

Delete multiple features easily in QGIS?

I have a vector layer being rendered in QGis. I want to delete various features in the layer. I'm currently deleting each node by selecting the node through node tool and then pressing the delete ...
8
votes
5answers
297 views

How to ensure uniform colour for DEMs?

This is a silly question, but one I've been trying to figure out for a while. I have two Aster DEM tiles, one next to the other. How do I ensure uniform colour for both?
2
votes
1answer
368 views

What is the easiest way to let a user upload overlayers to openlayers (Geoserver/Mapserver)?

I need to let a user upload vector layers he created with QGIS or MapInfo professional to my website (using OpenLayers as client and either Geoserver or Mapserver as WMS). What will be the easiest ...
2
votes
1answer
190 views

Road graph tool crashes, but works with sample shapefile [closed]

When I try to calculate the distance between two points using the "Road graph" plugin in QGIS (1.8.0-2, on OSX 10.8.2 ML), QGIS just crashes. It does work with the sample shape file from ...
3
votes
1answer
1k views

Why do OpenLayers layers appear shifted in map composer?

I'm having trouble with the OpenLayers Plugin of Qgis and the map composer: If I create an OSM-background layer and if I want to export this, the OSM-Layer looks perfectly all right in the normal ...
3
votes
0answers
146 views

Are there any known problems using GPS connection in Android version of QGIS? [closed]

I install QGIS both my netbook (windows win7 starter) and My tablet (android 4.0). I can used GPS option in windows version and I can save location points from GPS. However, I could not manage same ...