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

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1answer
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How to completely uninstall and remove QGIS 2.8.1?

I want to uninstall and completely remove QGIS installation from my computer(windows vista). I have uninstalled it and when i try to reinstall it says it is already installed on the system.
5
votes
3answers
528 views

great circles in QGIS and export in 3857 webmap

My plan is to visualize great circles in a leaflet webmap. So coming from this great postgis article and R version I thought it would work like this in QGIS: create line from two points, store ...
5
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1answer
896 views
4
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1answer
371 views

How to horizontally align irregularly shaped point symbol to vector layer in QGIS?

Fairly new to QGIS and searching a method to graphically align my point symbols in the direction of the vector. The symbol represents a water valve in an irregular shape in close proximity to a vector ...
4
votes
2answers
3k views

Workflow for creating line features between two coordinate pairs in QGIS

I have a table of stream reaches with xy coordinates for their respective tops and bottoms. I'd like to convert the table to a feature, using the xy coordinates as the endpoints of the line. Any ...
3
votes
2answers
2k views

How to activate GRASS GIS 7 plugin in QGIS 2.8?

Apparently, my linux ubuntu setup of QGIS doesn't contain grass gis, although when I initially installed it last week I added grass gis to the command line. Anyway, I typed in once again and installed ...
3
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2answers
4k views

Converting/using ArcGIS *.style file for/in QGIS (QML or SLD)?

I have downloaded a dataset from a government organisation. it comes with a .style file. I use QGIS 1.8 on windows 7. Is there a way to use the .style file as a qml or sld? I have tried simply ...
16
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1answer
2k views

Can QGIS preserve layers when exporting to PDF?

In ArcMap, when you export data to PDF it preserves the layering within the PDF so that you can turn on/off individual map layers (within the PDF itself). When I export from QGIS to PDF, I don't ...
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3answers
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How to change null values raster values to 0 in QGIS?

I need help... I'm having problems with QGIS. I have some rasters that appear to have null values, even though I reclassified them to obtain a boolean raster :( How can I change the NULL values to 0?
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1answer
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How do I clip OSM basemap with a polygon?

I've created a map in qgis 2.0. The map uses the OpenLayers plug-in to add the OSM layer as a basemap. I would like to restrict the basemap to be visible only inside a given polygon defined in a ...
6
votes
2answers
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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.
5
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2answers
192 views

How can I modify the width and the precision of my database?

I have a database in txt format made of several columns of real numbers. Two column are integer, 17 are real (rounded to the first decimal) and 17 are real rounded to the second decimal. If I import ...
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2answers
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Total of attribute field of point layer per polygon layer

I have a polygon shapefile of many lakes, I also have a point shapefile of locations on those lakes where fish were caught. The point shapefile contains the attributes: Fisherman_iD, Fish_Caught, ...
5
votes
1answer
1k views

Identify Polygons on raster image

I have OS street view mapping as raster images. Is it possible (without the obvious of tracing each dwelling) to identify all polygons on each tile. To clarify, My ultimate aim is to produce a ...
4
votes
2answers
8k views

Which hardware configuration is necessary for QGIS?

What kind of hardware is necessary to run QGIS on Win XP? Closely related: Specifications for GIS desktop hardware
3
votes
1answer
429 views

QGIS display does not reflect projection

I have slight experience with ArcGIS, but am new to QGIS. I'm trying to set the projection of my map, and I understand that this is done by altering the CRS (coordinate reference system) of each ...
2
votes
2answers
4k views

Using scale bar units in QGIS composer?

I am using the scale bar of the QGIS composer (ver 1.8) and I don't understand how the whole thing works. Where can I set the units properly? The layers have idential CRS (WGS84), the settings for ...
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vote
1answer
1k views

How to go with…somewhat complex geological maps in QGIS?

Just a follow-up to this question QGIS: Line to polygon conversion. Not sure do i have to continue there itself... We are currently digitizing a geological map...which has 36 features in total. Some ...
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vote
1answer
4k views

Clip raster layer with *raster* mask layer in QGIS

Given two input layers 1. The clip layer - an arbitrary layer (though in my case it's a float 1 band geotiff) 2. The mask layer - a paletted raster in which every pixel is either NO DATA or a single ...
50
votes
5answers
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How to add Basemaps from Google or Bing in QGIS?

Like ArcGIS Desktop has the option of using basemaps from ArcGIS online, does QGIS have any such options?
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5answers
8k views

Identifying clusters in vector point data using QGIS?

I have a vector dataset of rural broadband data-points (how fast, etc.) and I'd like to explore if there are clusters of points with similar characteristics, and to plot polygons encompassing them. ...
12
votes
1answer
5k views

How to add labels outside of features?

I'm trying to achieve this kind of labeling using QGIS. Apparently, it doesn't seem to be easily supported. Would you have an idea for a workaround ? I managed to have circled text using ...
14
votes
4answers
4k views

How to place elevation numbers on contours with uphill orientation and position?

I want to orient my elevation labels uphill. Is that possible? I'm currently using the labeling tool from QGIS (not that one in layer settings). I want the labels curved and uphill oriented (and I ...
12
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3answers
8k views

How to create polygons with straight lines and right angles in QGIS?

I am running QGIS 1.7.0 on Mac OS X 10.6.8. When creating a polygon, how do I do it so that the lines are straight (90, 0 degrees, etc.) and when I create corners they can be right angles? For ...
9
votes
2answers
10k views

Converting point sets to polygon boundaries

I'm trying to convert sets of points to their respective polygon boundaries. I think this is something like a Voronoi diagram or Convex Hull, but not quite. I'm sure there's a technical term for it, ...
7
votes
3answers
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3D visualisation with open source GIS software [closed]

I'm searching for QGIS (or other open source GIS software) tools that can analyse XYZ data. Also I'm interested to hear about if anyone have migrated to non commercial software regarding geological ...
12
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4answers
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Is there a SVG symbol library for qgis?

Im currently using default simple symbol capabilities or dingbat fonts for point objects. Is there maybe a SVG symbol library for qgis that is a bit more extensive than that which is included? I've ...
7
votes
2answers
3k views

What are valid values for “data defined” labeling settings?

I'm using QGIS 1.8. I'd like to customize label features on an existing shapefile using the new label engine and it's "data defined settings" option. I'd like to know what the attribute table field ...
5
votes
1answer
2k views

QGIS on Mavericks

I have been trying to install QGIS on Mavericks and I have failed. Prior to installing QGIS, I installed GDAL using homebrew. I also installed Numpy, SciPy and pyqt using the detailed instructions ...
21
votes
8answers
36k 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, ...
15
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3answers
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Is there a way to manually place labels in QGIS?

Is there a way to manually place labels in QGIS? I have a map which has almost-duplicate labels in some places (e.g. E 1st St and 1st St) and I'd like to remove some of them. Also, I'd like to move ...
9
votes
1answer
5k views

How to fill gaps in SLC-Off Landsat 7 ETM+ Images with QGIS?

Explanation of the problem: On 31 May 2003 the Landsat 7 Enhanced Thematic Mapper (ETM+) sensor had a failure of the Scan Line Corrector (SLC). Since that time all Landsat ETM+ images have had ...
7
votes
3answers
1k views

Alternative to OpenLayers plugin for QGIS?

Are there any alternatives to OpenLayers plugin to have Google / Bing maps for QGIS projects? I need an high quality cartography (both aerial and street view) but OpenLayer plugin do not allow to ...
6
votes
2answers
732 views

How to symbolize features with NULL values in graduated symbology?

I have a polygon feature dataset, and an attribute from a different table that I join (one-to-one) within QGIS in order to symbolise the attributes as a choropleth map. However, not all polygon fields ...
5
votes
2answers
4k views

How to install QGIS on Centos 6?

I'm new on this; I really tried a lot before ask.. but nothing works. I did all that the qgis page says. Install ELGIS. after that i investigate and tried diferents comands.. but nothing works..the ...
5
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6answers
2k views

Creating multiple buffers using QGIS?

I'm new to QGIS and have no programming skills. Is there an easy/uncomplicated way to create multiple buffers around a line feature?
12
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4answers
6k views

Is it possible to connect to ArcSDE using QGIS?

Is anyone aware of any plugins, or any other way to connect and view data from an ArcSDE database in QGIS desktop?
11
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2answers
4k views

Running QGis from flash drive

How can I setup a portable QGis to run from a flash drive / USB-Stick? In the userguide for QGis 1.7 Wroclaw there is only mentioned the option of "--configpath". But to me it is not clear how to deal ...
10
votes
2answers
16k views

How to enable projection transformation in QGIS

My QGIS project has two layers, one layer is retrieved by Google layer plugin which fetches the static Google map image whose CRS is +proj=merc +lon_0=0 +lat_ts=0 +x_0=0 +y_0=0 +a=6378137 +b=6378137 ...
9
votes
1answer
636 views

How to call the interpolation plugin from the python console?

I would like to call the QGIS interpolation plugin function (TIN method) (Raster->Interpolate) from python console. I can't find the corresponding function within QGIS API or within the ...
9
votes
5answers
26k views

How to create a new layer from a selection in QGIS?

I have been using ArcMap for the last three years. But I am now considering switching to Quantum-GIS. Is it possible to create layers from selection in QGIS? I am using QGIS 1.7.4-Wroclaw. UPDATE: ...
4
votes
4answers
1k views

Checking if polygon fits inside another polygon using ArcGIS or QGIS?

How do I check if one polygon fits inside another polygon? Furthermore how do I automatically check if one polygon fits in other polygons of my shapefile? I have a shapefile with thousands of ...
4
votes
4answers
8k views

Measuring the distance between lines and points in QGIS

Using QGIS - I have a vector of fault lines. I have point data in the form of a csv which I have also loaded into QGIS. I need to know how far each point is from the nearest fault line then enter ...
4
votes
2answers
1k views

Get a pixel value

How can i do this operation: I want to get a pixel value fro the satellite image (Landat, GeoTIFF, 7 bands) using qgis-python. What operators should i use? (for example in qgis's Python Console) ...
2
votes
1answer
2k views

How to produce multiple maps with same layout for different layers' extents?

I have an area which is divided into several zones the borders of which I have defined as separate layers. The layers are defined by sql queries on a postgis table of line segments joined with a ...
22
votes
2answers
7k views

Does QGIS have the equivalent of ArcGIS's Layer (*.LYR) file?

Using ArcMap, it is possible to add a dataset (eg a shapefile) to the map, and configure the layer's properties (such as the symbology, table joins, switching some attributes off in the Identify ...
12
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6answers
5k views

How to identify duplicate attributes in a field?

I have a point shapefile with thousand of points. It has an ID code field that supposed to be unique. Every now and then the data entry clerk wrongly type the id creating duplicates.Right now I'm ...
11
votes
2answers
3k views

How to get FGDB support in GDAL 1.9 without compiling?

I was hoping that I could use the 'master' (nightly-build) version of QGIS to get fgdb support without compiliing (I'm not a developer and frankly have wasted days of productive time trying to get ...
10
votes
1answer
5k views

How to resample GeoTIFF images to the same resolution?

I have two geotiff images that I would like to resample the same resolution. If I use ArcGIS this would be easy to do. But using QGIS I don't know how to do this. Some help will be very appreciate. ...
8
votes
3answers
1k views

Calculating all distances from single points to multiple polygons

I have two layers: a point layer defining properties (95 objects), and a polygon layer defining plots of land associated with the properties (211 objects). Each point relates to one or more polygons. ...