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

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1
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2answers
362 views

Aligning data from PostgreSQL and ArcGIS Desktop in QGIS? [closed]

I am pretty new to ArcGIS and QGIS. I have loaded some geometry data in QGIS from my postgres database, then I have also loaded the same data in ArcGIS. Then from ArcGIS i have created a shapefile ...
1
vote
1answer
529 views

Why does ftools' difference tool fail?

I have an area polygon with rocks on it i want to use difference to map the soft (ground, not rocks) cover. to do that i try using the (ftools) vector>geoprocessing>difference getting an empty ...
4
votes
1answer
51 views

Is there a QGIS mailing list that only announces new releases?

Is there a mailing list for qgis that announces only new releases / new binary packages? Thanks.
2
votes
1answer
327 views

update tables data dynamically

Can u help me in creating a trigger and function so that every time i change the flag in table A the buffer distance should get changed and also its geometry field also , ie the polygon area? I have ...
5
votes
2answers
4k views

Can I export a polygon shapefile to a Garmin device?

I want to export the boundaries of a parcel to my GarminMap 60CSx. I downloaded a parcel map from the county, and I want to use it to walk the perimeter. Does the .gpx format support polygons? Or is ...
3
votes
0answers
101 views

How to digitize 90 degree angles? [duplicate]

Possible Duplicate: How to create polygons with straight lines and right angles in QGIS? In QGIS 1.8 is there a way to digitize buildings etc. with perfect 90-degree angles, Or, edit a ...
3
votes
1answer
297 views

Does QGIS DB Manager plugin lock PostGIS transactions?

I do most of my geospatial analyses in PostGIS 2.0 using PgAdmin III. I use QGIS 1.8 for visualizing my data but also for querying my database using the DB Manager plugin. Sometimes (quite often ...
4
votes
3answers
854 views

How to create an intensive map of Russia using QGIS or any other software?

I am trying to create an intensive (heat) map of Russia. I have an excel sheet of 36 Russian regions and their corresponding values. I know that there were similar questions: How to create a map ...
4
votes
2answers
2k views

QGIS exporting huge SVG [duplicate]

I'm having trouble exporting an SVG(or a PDF for that matter) from the QGIS print composer. I have a relatively simple map that should, when exported as an SVG, be maybe around 1MB in size, tops. But ...
1
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0answers
25 views

Where can I find the 1-band color raster plugin for QGIS? [duplicate]

Possible Duplicate: How to install “1-band color raster color table”? I'm searching for the 1-band color raster plugin. What is the essential repository? Or is there another tool for ...
4
votes
3answers
3k views

How to add points in degrees + decimal minutes to QGIS?

I try to add geocaches with x,y coordinates in a xls-table to qgis and convert to shp.file. Usally geocach-coordinates are like this: N 51° 29.440' E 011° 56.430' (WGS84) (in german its called ...
7
votes
4answers
2k views

Calculate polygon field based on neigboring polygon attribute

I have a vector shape with many different sized polygons each possessing an own class name (for instance "houses", "houses with offices", etc ...) I want to assign a new field to each polygon ...
9
votes
5answers
3k views

How to modify single Pixel values in QGIS?

I would like to modify a raster (pixel values) in QGIS. The plugins "value tools" can easily provided me with the value of the pixel of my raster. However I know know how to modify it. I have found ...
6
votes
1answer
6k views

Converting Shapefile to MySQL?

I have used Grass GIS imported a .shp file; I now want to export this file to MySQL. I understood that MySQL will contain the function of all three the files necessary in a Shape file system (.shp - ...
3
votes
1answer
741 views

Which parameter values should I use with QGIS Heatmap plugin?

I've read all the posts and docs about the heatmap plugin but can't seem to get it to work. The map is the size of the United States and has a little over 2000 points. I've tried small radi (1 ...
2
votes
1answer
293 views

QGIS & GeoTIFF clipping Error “-srcwin 5897 137 0 0 falls outside raster size of 11083x4158 or is otherwise illegal.”

I'm trying to clip a GeoTIFF file and unfortunately I'm getting the following Error "-srcwin 5897 137 0 0 falls outside raster size of 11083x4158 or is otherwise illegal." From another post ...
2
votes
1answer
77 views

Are there any document icons for the qgis mimetype?

In a default Ubuntu install (QGIS 1.8.0) no document icon is associated with the mimetype 'application/x-qgis-project'. As a consequence every saved QGIS document is interpreted by the OS as being a ...
5
votes
0answers
644 views

How to automatically format the legend labels? in QGIS

I have to do 10 maps (for a start) with "style" -> "graduate" with quantile mode. I need to format the label of the different ranges so that the legend looks comprehensible: Instead of having 1.0000 ...
20
votes
2answers
12k views

How to convert .shp into .gpx using QGIS?

I'm newbie using QGIS. I would like to convert .shp into .gpx. So, using Qgis, I open my shapefile and I tried to "save as" gpx but it gives an OGR error: creation of field ObjectId failed (OGR ...
1
vote
1answer
2k views

rpy2 installation ERROR “Tried to guess R's HOME but no R command in the PATH”? [closed]

I tried to install rpy2 (pip install rpy2). I want to use the SDAPP4 extension with QGIS (QGIS shows up the message missing rpy2...). The system tells me always the same error: Tried to guess R's HOME ...
7
votes
2answers
823 views

How can I make segmented roads appear as one line?

I am footling around with Quantum GIS and the British OS Strategi dataset. If I render the roads with a simple line style they look fine: However, if I apply something slightly fancier, it looks ...
5
votes
1answer
645 views

How do I allow users to select features with the mouse?

I am using PyQGis API to create a custom application. How do I allow users to select features with the mouse? Is there a mapTool for this? Surely with a product as powerful as QGis there must be. ...
7
votes
1answer
379 views

What constitutes a valid spatial layer when connecting QGIS to MySQL?

I'm trying to work with a MySQL 5.5 table using QGIS 1.8. I can do "Add Vector Layer", choose "Database", and successfully connect to the MySQL connection I previously set up. QGIS shows me a ...
1
vote
0answers
130 views

How can I access lost panels in print composer? [duplicate]

In QGIS, I no longer have access to the panels in the composition for printing window (layout, history, object properties). QGIS 1.8.0 on a Mac. What I already tried : The right click on the ...
5
votes
2answers
508 views

Extract certain area of contours/satellite images

I have 2 satellite images (jpeg2000 format) and 2 xyz-files from the same area. I am trying to extract certain region from the area including contour lines and the satellite image in order to import ...
1
vote
0answers
76 views

Problems with CRS in Qgis [duplicate]

Possible Duplicate: Raster incorrectly reprojected to OSGB(27700) The crs is clearly off when the gridlines run straight and the map lines run at an angle. I have set the crs to match the ...
20
votes
3answers
6k views

How to easily edit attribute data using Regular Expressions?

I am writing a tutorial for MSc students that uses QGIS. One of the tasks requires the attribute data to be modified (see pdf draft of tutorial here if interested ). The question is how to get them ...
2
votes
1answer
133 views

plugin 'hook' when writing with Python

Just a conceptual question... when writing a plugin using Plugin Builder 1.8.3, where does the script get connected to the application instance objects? As an example (taken from ...
1
vote
0answers
24 views

Qgis printing bug [duplicate]

Possible Duplicate: How to reopen hidden panels in print composer? I am new to QGIS and I have a problem with printing, After a bug, I do not have longer access to the functionality of ...
5
votes
2answers
553 views

Can you print cross-hatch area fills like they appear on screen?

I'm trying to use a cross-hatch symbol on polygons in QGIS. When displayed on screen, they look just fine - both in the map and in the composer. The problem is when they are rendered to an image ...
2
votes
2answers
610 views

Does “size scale field” in QGIS actually work?

I'm having mixed results with the 'size scale field' aka graduated symbols in QGIS. Some forum posts out there say this feature is broken - others can get it to work.
2
votes
1answer
85 views

What units are used in GRASS Rasterize?

What units are used in GDAL Proximity or GRASS Rasterize? - 'new size' parameter
1
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1answer
834 views

DLL load error with Gdal polygonize in QGIS 1.8 (windows 7) [duplicate]

Possible Duplicate: Qgis polygonize problem - DLL load fail [I had already posted this question, but was closed and redirected to a supposedly duplicate question. I'm re-posting since I ...
2
votes
0answers
144 views

How to make lines styles with offset join properly?

I want to draw the lanes of a two-lane street in different colors. I tried to apply an offset to a symbol layer which works fine for a single line but the ends of two connected lines do not join ...
4
votes
1answer
281 views

Exporting 3D geometry from PostGIS 2.0

I have a table containing 3D geometry in a PostGIS 2.0 database (the geometry is of type LINESTRING Z). I need to get the geometry out and into a DXF, DGN or 3D Shapefile. What is the easiest way to ...
7
votes
1answer
918 views

How to call GRASS modules in pyQGIS?

I wish to use a Grass module (v.to.db) in QGis, without the grass toolbox. I tried with the Python console, but to no avail : Using Sextante plugin but obviously it didn't know all the grass ...
1
vote
2answers
169 views

Is it possible to import SAGA colour styles in QGIS?

iam still using QGIS and SAGA independently in my productive use (despite the excellent SEXTANTE toolbox, which is sometimes a little buggy). SAGA has some very nice default styles and i am wondering ...
1
vote
1answer
177 views

Is there a straight way to copy or clone a QgsVectorLayer Object?

Is there a straight way to clone or "deepcopy" a QgsVectorLayer Object with python? Unfortunately the python module "copy" is not successfull with that. Thanks in advance! nikolaus
8
votes
3answers
2k views

calculate area of vegetations in a raster file

How do I calculate area of several vegetation types in a raster (.img file type) image. They are color coded. Am using QGIS (1.8.0) and ERDAS 9.2.
5
votes
1answer
529 views

How can I create a pollutant dispersion raster in QGIS?

As my previous questions have indicated, I am working on an air quality problem where I have a dataset of industrial emissions that consists of a location (long, lat), and an annual volume of ...
5
votes
1answer
909 views

Raster incorrectly reprojected to OSGB(27700)

Ubuntu 12.04, QGIS 1.8.0, GDAL/OGR 1.7.3, GEOS 3.2.2 Open a Spatialite db with OS Mastermap poly layer (EPSG:27700); Add OpenLayers Plugin (1.0) from QGIS offical repository; Add a Google Satellite ...
0
votes
0answers
615 views

Export dxf files for use in Sketchup

the export to dxf seems like it worked, but Sketchup will not import it. I don't think this is a Sketchup issue, as Sketchup imports other dxf files just fine.
2
votes
1answer
196 views

Problems with QGIS (v 1.8.0) layer labels [closed]

I have a PostGIS (v 2.0) layer representing lakes. The attributes "chinchar" and "chintrans" contain Chinese characters and Pinyin (Roman) characters in UTF8 format. When I use Layer -> Labeling in ...
2
votes
2answers
2k views

QGIS - extract raster values greater than 0

How can I extract values > 0 from an overall raster? I have a water level grid and a DTM from which I've derived flood depths (using the raster calculator) but obviously the final result contains ...
2
votes
2answers
679 views

QGIS 1.8 Did Not Install Properly— Will not recognize modules or DLLs— conflicting with existing PyQt?

I know this has been asked and re-asked, but I can't seem to get any of the proposed solutions to work. Upon clicking the start menu shortcuts to QGIS desktop, nothing happens. When I run from ...
2
votes
1answer
400 views

how to load a raster into the Map Canvas using QGIS Action

Is it possible to write an Action in QGIS that will load a raster into the current map canvas based on a url/path of the raster as specificed in the attribute table of a shape file? The shape-file is ...
3
votes
0answers
458 views

Problem connecting QGIS to MySQL [closed]

I'm trying to create a new vector layer and store it in a MySql-database, but when I test the connection I get an error with no detailed information at all. If I give an erroneus password I get a ...
2
votes
0answers
76 views

queried layer is not updating after drawing new feature in original shapefile

I have a project in qgis 1.8 where I added the same shapefile 3 times. On 2 of them I made a query. The third one is for edditing purposes. When I change the value of one of the features (in the ...
2
votes
3answers
3k views

How can I fix “ImportError: No module named qgis.core”?

First of all, I'm using Python 2.7.3, QGIS 1.8 (Lisboa) on Windows 7 pro 64 bits. Now let's go to the actual question: I have written some code (Python) that works well within the QGIS built in ...
3
votes
1answer
1k views

QGIS Attribute Table Not Displaying Data

Using QGIS and one minute I could see the attribute table, the next minute I couldn't. Using QGIS on Linux Mint 13. I tried purge/autoclean/reinstall to get a completely new download of all ...