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

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Exporting QGIS attribute table to excel [duplicate]

I have a million rows in the attribute table, with lat/lon columns that I want to export to Excel. Selecting all the rows causes QGIS to crash. Is there another way to do the export? The million rows ...
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0answers
97 views

gdal_merge.py aligns incorrectly at the seam of two GeoTiffs

I am trying to merge four GeoTiffs from the National Elevation Dataset (EPSG: 4269) into a 2x2 DEM using gdal_merge.py. For some reason, when it merges the upper two NED rasters, gdal produces a seam ...
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68 views

QGIS very slow startup on Mac

I am experiencing startup times of c5 minutes (!) for QGIS 1.8 on my Mac Mini with 2.4GHz processors and 8G RAM. I have just 4 python plugins and only a handful of shapefiles/data layers so I can not ...
2
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3answers
142 views

How to minimize the number of nodes in a polygon?

I'm building a web application that will be transferring polygons from server to client. Initially, the shapefile is coming from an external source that I have no control over. Often, I find polygons ...
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1answer
206 views

How to save a joined spatialite table when each table contains PKUID fields?

QGIS 1.8.0 -- QSpatialite 6.0.7 -- Windows XP I have spatialite tables joined together that I need to save as a single table, but an error-message says that QGIS can't save the table because there ...
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1answer
81 views

How to reopen a plugin-window in QGIS?

I am currently taking my first steps in playing around with programming a plugin in python 2.7 for QGIS 1.8. While my plugin does what it should, I would like to make it more userfriendly. At the ...
2
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3answers
163 views

How to classify shapefile data into groups?

I have a map with a shp file containing information on land use. The attribute table has over 10,000 rows. I need to classify this information into 6 groups to represent 6 colors on my map. I know ...
2
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1answer
130 views

GPL License - App only uses QGis components as a GIS display

I'm still not clear on QGIS licensing ... I am contracted to write a system that has nothing to do with GIS and GIS analysis, but goes around managing animal tags, and I want to use QGIS to draw on a ...
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0answers
13 views

Sextante Modeler Error “global name os is not defined” [duplicate]

I want to generate a model whic reclassify radter values. So i added Saga reclassify grid values tool to Modeler and saved the model. When i run the model i got this error both on Ubuntu OSgeolive 6.0 ...
0
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1answer
104 views

In QGIS can I show just the lines in a Postgis query? How can I do that?

I have three tables in Postgresql, each table with one layer of lines. I want to show the path of an initial line to another final. Is it possible executing a SQL query? Thanks My three tables are ...
0
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2answers
193 views

Why is QGIS reading in my CSV numeric data as string data, and how do I change it? [duplicate]

QGIS keeps reading in my numeric data from .csv files as string data. This means I have to figure out how to read it in with the proper data type, or convert it back to numeric inside of QGIS, ...
2
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3answers
157 views

How to delete polygons less than a certain area?

I'm trying to delete all polygons with an area smaller than a certain give value. Is this possible in qgis? The goal here is to delete all the islands off a map.
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2answers
136 views

Why is it so hard to download only a part of OSM data by attribute tag?

Is there any online service that allows to download only one thematic layer of the OSM data for a specific geographic region? For example all objects related to vegetation (trees, grassland,...), but ...
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2answers
174 views

SAGA, GRASS Raster values to null

I want to make the cells which values "1" to null in QGIS with Grass or Saga tools (exactly Saga).
0
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1answer
71 views

Is it possible to export an image that can be zoomed-in on?

I am using QGIS on a Mac. I would like to export my map so that the viewer can zoom in on it, just as I view the map on my QGIS canvas. I am not sure how to word what I want. If you see the map ...
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0answers
35 views

Print Composer doesn't display my map! [duplicate]

So I have created a map that I need to share with my coworkers. When I open Print Composer and add map, my map does not appear in the rectangle that I create. It is just blank. I try updaing the ...
8
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5answers
1k views

What is the best free web GIS browser?

Hi I have created several projects for several different clients. Each project has OS maps, shapefile layers from Government Bodies, Shapefile layers created, AutoCAD dxf loaded in (in various ...
2
votes
2answers
137 views

merging layer stored in PostGIS

I have a bunch of layers stored in PostGIS that I want to merge. I have spent quite some time investigating various approaches but I ket tripping over getting the GIDs to update properly. In the end ...
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0answers
430 views

Line to Polygon via Polygonizer in QGIS

My question is in the same vein as this one. I'm attempting to convert precipitation lines (Precipitación Media Anual) to a polygon for Mexico in QGIS using the Polygonizer plugin. After running the ...
0
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1answer
222 views

QGIS Trace Tool; Error

I have installed the traceDigitize tool from the experimental repository in QGIS 1.9.0 Lisboa. My understanding of the tool is that you have to: Add 2 layers to QGIS Desktop. My empty shapefile to ...
2
votes
2answers
148 views

How to determine the coordinates of the corners of the raster layer

How can we determine the coordinates of the corners of the raster layer? The image opens function QgsRasterLayer.
8
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3answers
599 views

Howto setup and use a remote GIS workstation (QGIS,GRASS,PostGIS)?

I'm using QGIS (and sometimes GRASS and PostGIS) on my 2009 MacBookPro for my thesis project. I was wondering (during an endless batch generalizing in QGIS) if I can set up a server so I can work from ...
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1answer
53 views

Is there any “proper” way of setting the viewport for QGis Time Manager?

I'm working on video visualisation for some geo data. Everything works fine for me except the viewport that the time manager plugin is using for image frames. It makes image frames size of actual map ...
9
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1answer
236 views

How to find the buildings (polygons) a user can see from a given location (point) and orientation (angle range)?

I would like to retrieve the set of buildings I can see from a given location (point -lat,lng) and orientation (interval of angles) + certainly with a given depth (e.g. 100 meters). Ideally I would ...
2
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2answers
312 views

How to calculate area in sq km of an ellipsoid shapefile

In QGIS, I often find myself setting up projects with an ellipsoid coordinate system (e.g. WGS84) so that the resulting maps have lat lon scales, etc. Often in these projects I also need to do some ...
2
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1answer
793 views

How to reclassify a float raster?

I have three rasters which represent distance (in metres) from certain things (bus stops, parks, libraries). I would like to reclassify these rasters so that they get integer values based on the ...
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0answers
556 views

Sextane script error (os is not defined)

I want to build an analysis script using Sextante 1.0.9 on QGIS 1.8.0. I find an example script in Youtube. I tried this code but never worked always getting error. People say that Sextante is ...
0
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1answer
59 views

Full Easting and Northing coordinates values cannot be encoded in GRASS r.water.outlet in SEXTANTE-QGIS

The Easting or Northing coordinate parameter accepts only 5 digits. The Easting and Northing values for my outlet are 6 and 7 digits long (integer). How can they be encoded in r.water.outlet? Can ...
3
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0answers
243 views

Error in uploading data in QGIS cloud

I want to publish my .shp file using QGIS Cloud plugin. I signed in to qgiscloud.com (free). On create new database it will auto create dbname='fbeudp_mfaphk' user='fbeudp_mfaphk' ...
2
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0answers
94 views

Raster area (QGIS) problem explained

I would like to know the area that each value in a raster has... The raster I have has values from 2-15 and I would like to know the area that each value is occupaying within my polygon... Thanks! I ...
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2answers
163 views

Qgis 1.8 is not recognizing sdw file

I'm running qgis 1.8, and trying to load a sid file into my map. It imports fine, but seems to ignore the sdw file that comes with it, as the raster shows up without any apparent georeferencing. Is ...
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0answers
152 views

Hardware specifications for QGIS

New to QGIS, running on a Mac with adequate RAM & HD space. Looking to future I find no real hardware specifications. I want to find more information, can someone point me towards QGIS forum that ...
3
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0answers
69 views

How to analyze the signatures for a Landsat clasification with Sextante in Quantum Gis

I’m defining my training data for a Landsat classification. I´m digitalizing the polygons with the field data in QGis and I want to analyze the signatures of the Landsat images to avoid errors. In ...
4
votes
1answer
835 views

OpenLayers Plugin 'traceback' error

I'm aware the 'traceback' OpenLayers plugin error has been dealt with before, so apologies for raising the issue once again. Unfortunately for me, the solutions posted were way over my head, e.g. ...
9
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2answers
346 views

Can I add an ArcToolbox tool to QGIS?

I have been using a publicly available tool in ArcGIS called SPreAD-GIS. It is a series of python scripts that are "implemented as an ArcGIS toolbox" (with tbx file). I am new to QGIS. Is there a ...
0
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1answer
150 views

Sextante grass folder incorrect?

What is the correct grass folder in Sextante? I alway get this message: The specified GRASS folder does not contain a valid set of GRASS modules. Please, go to the SEXTANTE settings dialog, and ...
14
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5answers
599 views

Can I transfer custom QGIS settings from one computer to another?

Can I export custom general settings from my QGIS installation to a file so that I can transfer the settings to QGIS on a different computer? Does QGIS have them already saved to a file located ...
0
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1answer
140 views

Saving part of OSM shapefile in QGIS as GeoJSON strips 'name' field to 25 characters long [duplicate]

I want to copy part of OSM data in ESRI Shapefile (downloaded from http://download.geofabrik.de/europe/ukraine.html ) and save in in GeoJSON to style later in Tilemill. After saving, I see that ...
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vote
2answers
146 views

Is it possible to change a Geotiffs CRS?

Hi I have created a Geotiff from the Bing Aerial photography. As it is automatically in WGS 84 it inserts perfectly into QGIS, however this image is of no use to me outside of QGIS. I need to ...
0
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0answers
38 views

Why are areas of raster and polygon after digitization not matching? [duplicate]

I have followed the answer given in this question:How to calculate the area of rasters in QGIS? I vectorized and calculated the area using geometry columns but I a faced a strange problem. When I ...
1
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1answer
50 views

Removing Plugin Repository sites that fail to load

New here & to QGIS. Loading several plugins I noted that several sites seem to not load ( example "catais.org" or "GIS-LAB.info". Cannot actually find this site(s), I assume they are defunct, ...
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1answer
108 views

How to change delimiter in attribute table of QGIS?

I have imported a .kml file into QGIS, and the data is all shoved together into a single field like this: Fine, it's pipe delimited - easy to change the delimiter like in LibreOffice calc imports I ...
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0answers
260 views

How to calculate average value within a polygon(in Qgis with Python)?

Now I have a point and polygon shapefile and I want to calculate the points' average value within each polygons How to do it with python? I tried to find out but google gives me a lot of raster ...
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2answers
274 views

area values determined with field calculator become null when saving

using field calculator in Qgis 1.8.0 to get the area, it shows just right at first but when I save it, the values become Null. help please
1
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2answers
273 views

cannot see map in composer

Sorry if this is a repeat, but I couldn't find an answer here. And sorry if the answer is completely obvious, but I do appreciate your assistance with my first QGIS map. When I try to use composer ...
7
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1answer
142 views

How to save python session in QGIS?

After running a lot of scripts in QGIS' python console, I have more than 10 dictionaries and lists, and I need these for further analysis. Is there a way to save python session, with all these ...
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0answers
245 views

SAGA kernel density error with Sextante Modeler

I can succesfully perform SAGA kernel density analysis with Sextante (1.0.7) in QGIS 1.8.0. But i want to built an automated tool for this job with Sextante Modeler. But i got foolish errors. This ...
2
votes
1answer
54 views

why can I only define 6 custom CRS?

Using Q GIS 1.8.0 - I am trying to create several custom CRS definitions for the purpose of rectifying several split areas of a census shapefile. In the "Custom Coordinate Reference System Definition" ...
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1answer
38 views

QGIS - Importing USGS DRGs

I have asked about this before. If I import a USGS DRG raster for Anchorage, Alaska using EPSG:26706 - NAD27 / UTM zone 6N all the UTM coordinates are correct. Now if I want to look at the ...
1
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1answer
156 views

Sorting points with QGIS

I have a very good idea of what I would like to do but I really do not know if it is possible with QGIS. I have points that each one corresponds to a group size and I would like to use GIS to sort ...