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

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How to export shape file to SpatiaLite

I have a shapefile with one layer. I can open it with QGis. Now I want to convert this shapefile or layer to Spatialite database. How can I do it? Is it possible to do with QGis?
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3answers
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How to move vectors to specified coordinates in QGIS?

I have a layer of vectors located around, say, (100, 100), and I want to move them to new coordinate like (1000, 1000). How should I do it? Preferably using QGIS.
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2answers
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How can I join several raster files using QGIS?

I'm new to QGIS. How can I combine multiple raster layers into one layer? The raster images are of different areas with very little overlap. The goal is to bring numerous town plats into one project. ...
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5answers
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Get Raster Values from a Polygon Overlay in Opensource GIS Solutions

I have two layers. A polygon-shape-layer with many tiles and a raster-layer containing CORINE 2006 land cover with many categories in a colourmap. I want to obtain for each polygon in the shapelayer a ...
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Is it possible to export GeoPDF from QGIS?

Is there any plugin for QGIS which would help me in exporting the map document as a GeoPDF ?
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Are there open-source alternatives to ArcGIS online that can be hosted on my own server?

I know this might be too broad topic. But I am looking for web-GIS portal similar to ArcGIS online that is self-installable (configurable) to be hosted in my private server. The main features should ...
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2answers
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Is it possible to manually correct a raster DEM (OpenSource)?

Is it possible, to correct a raster DEM by changeing the raster-cell-values manually, like by "painting"? My DEM (ASTER) have one small error where the elevation is about 300m below the actual ...
12
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4answers
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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 ...
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3answers
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How can I iterate over map layers in QGIS python

I'm having trouble figuring out how to iterate over map layers. I can access the currently highlighted layer in the table of contents via iface.activeLayer() but I want my code to operate on all ...
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3answers
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How to programatically check for a mouse click in QGIS

I want to know how to check for a mouse click in QGIS. I am trying to write a python plugin and want to provide functionality similar to the "Select Single Feature" tool that already exists in QGIS. ...
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2answers
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How to concatenate labels in QGIS?

I'm using QGIS 1.8 on windows XP machine and I try to do a concatenation of several fields to label the names of my local roads in the attribute table, but I can not find the correct syntax. The first ...
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2answers
560 views

How to clean such a bad shapefile for routing ?

I am trying to clean a shapefile to make it usable for routing with pgrouting, postgis, postgresql. Here an intersection, it seems to be connected but when we zoom …. It is not: Same here : ...
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How to convert a vector layer to raster?

In qgis in the raster menu there is an item "convert vector to raster". This behaves strangely - I do not understand how it is supposed to work. I can select a vector file, an attribute and an ...
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2answers
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How to handle multiple map frames with different layers in one print layout?

Often I need two (or more) map frames in map layout to present different data next to each other. It is easy to make multiple map frames in QGIS Print Composer. BUT... It is in the nature of my work ...
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4answers
14k views

Feature comparison between QGIS and ArcGIS for Desktop [closed]

I am learning to use QGIS and ArcGIS for Desktop but I cannot find the differences between them. What are the differences between the capabilities of QGIS and ArcGIS for Desktop?
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Is there a way to use “Select by Attribute” in QGIS using a python command?

is there a way to use the function "Select by Attribute" in QGIS using a python command? In my plugin the user should enter a value via a GUI and this value should be used in a function which selects ...
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2answers
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How to join external tables with a shapefile's attribute table in QGIS?

I need to join a .csv table into an attribute table of a shapefile. I wanted to do this with QGIS and i don't seem to find anyway of doing it. I know that the mmqgis plugin does it, but my shapefile ...
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2answers
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polishing qgis map for publication using inkscape

I have a problem modifying the map I created in QGIS. I need to add some text on the map and axis labels. Apparently, labels cannot be rotated in qgis, so this I need to do in inkscape or in a related ...
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1answer
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Merging adjacent polygons in shapefile that has been split at tile boundaries?

I'm currently using building data from the Ordnance Survey Vectormap District and I've noticed that a lot of building polygons are split in 2 because of the way the OS split up the shapefile. This is ...
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1answer
350 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 ...
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5answers
5k views

Is it possible to connect to ArcSDE using QuantumGIS?

Is anyone aware of any plugins, or any other way to connect and view data from an ArcSDE database in Quantum GIS desktop?
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2answers
381 views

How to sort by multiple fields at the same time?

Is it possible to sort multiple fields at the same time in QGIS? For example, I'd like to sort a table by state name, and then within each state, sort by county name. This would be the same as the ...
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1answer
992 views

How to define Winkel Tripel in proj 4.8.0?

I have QGIS with proj 4.8.0 installed. I'd like to add Winkel Tripel projection which seems to be defined as +proj=wintri But that definition string does not work. Is this a bug in my proj version, ...
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0answers
265 views

Qgis 2.0: Disable log messages? [closed]

Is it possible to disable log messages in QGIS Dufour? When I work in QGIS 2.0, log messages increase to more than 2000 and it makes QGIS very slow. Then I save project and open it again, then QGIS ...
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4answers
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How to model a graveyard - one point per deceased or one per grave? [closed]

This is a continuation of my previous question about our project on how to economically get away with the implementaion of a graveyard in a GIS system… On the graveyard we can find Regular ...
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3answers
679 views

How to update file locations in QGIS projects?

I don't know if there is an answer to this question, aside from the obvious. I have about 30 different QGIS Project files for 30 different clients. Each is saved onto my computer and all their ...
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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 ...
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4answers
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shp2kml license expired, looking for free solution

So I work for a small African non-profit. I do all the GIS and data work. Most of the layers I create, I convert to kml layers so my boss can then use them quickly and easily in Google Earth. But now ...
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6answers
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How do I make a heat or Choropleth map that uses polygons in QGis?

I've been playing around with the heatmap plugin for QGIS and I am wondering if it is possible to make heatmap with using a similar plugin/tool that uses polygons as well as points? I would like to ...
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2answers
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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. ...
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4answers
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How to create equidistant points in QGIS?

I am trying to create points (new layer) at specific distance along the road (existing layer) in QGIS. This gives solution for ArcGIS. How to achieve this in QGIS? This one explains how to create ...
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How to perform Raster Reclassification in QGIS?

Is there a way to do reclassify a raster image to Qgis? In Arcgis you can do that in Spatial analyst Tools→Reclass→Reclassify Any ideas?
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1answer
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How can I uninstall Quantum GIS that was installed using OSGeo?

I installed QGIS using OSGEO4W, and would love to know how to uninstall it, because when I go to "Control Panel > Programs > Uninstall" the program does not appear in the list of installed programs. ...
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2answers
462 views

How do you protect your PostGIS credentials when using QGIS 1.7?

I'm fairly certain this should be a community wiki, but I don't know how to make it one. So if an admin sees this please change if appropriate. So.....How do you protect your PostGIS database data ...
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1answer
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How do I build a custom form for entering attributes in QGIS

I've done this many times in ArcGIS and ArcPad but I don't even know where to start building a custom form for data entry in QGIS. I would like to do this for field operations--QGIS would make a good ...
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1answer
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How do I calculate the latitude and longitude of points using QGIS?

I'm trying to figure out how to calculate the lat/long of points using the QGIS field calculator. Is there an easy way to do this? I saw a previous related question, but it deals with a more advanced ...
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2answers
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Is it possible to create Thiessen polygons around nodes in QGIS?

Is it possible to create Thiessen polygons around nodes in QGIS? e.g. http://en.wikipedia.org/wiki/Voronoi_diagram
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1answer
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How to produce high-resolution DEMs from new Sentinel-1 data?

This is a general question relating to the new Sentinel-1 data. I'm interested in the potential for using this data to create high resolution DEMs in GIS (I use QGIS), to investigate archaeological ...
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1answer
279 views

How to copy the color styling to a color column in a layer's attribute table?

I have a polygon layer in QGIS that I have applied a random color style to each polygon. Under Layer Properties -> Style I selected a Categorized style and then generated a random color ramp. I added ...
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3answers
318 views

What is the most appropriate journal for publishing a paper about data collection with QGIS and mobile equipment?

I am a QGIS user, and a few months ago, we used QGIS on a PC Tablet to collect data on nesting birds on a cliff directly on the field. The principle is to have QGIS installed on a PC-Tablet with an ...
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2answers
9k views

How to open a GeoJSON file with mixed geometries in QGIS?

If I have a GEOJson file, for example a file named test.js with inside the following: { "type": "FeatureCollection", "features": [ { "type": "Feature", "geometry": {"type": "Point", "coordinates": ...
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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 ...
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1answer
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How to create desire lines in QGIS?

How can I show the flow coming from an Origin-Destination matrix as desire lines? I need a result like the one in the picture below. I need to scale them proportionally to its value (coming from a ...
11
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1answer
3k 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 ...
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2answers
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Moving points onto lines (~neighborhood)

I do have two vector layer, of which one is a point layer based on "events" by remote sensing and the second one is a line layer from local research. In my case these are earthquakes and tectonic ...
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How can I map a matrix of origins and destinations in QGIS?

I have a central point on a map, and I have other points in a separate layer (the location of a venue, and the origin cities of the venue visitors). Is there a plugin which would generate output ...
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How to use label classes, expressions, and annotations?

I've always found that when it comes to python, vector analysis, QGIS gives ArcGIS a run for its money, hell some of the qgis plugins exceed ArcGIS's performance by a few hours; however, I always have ...
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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 ...
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1answer
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Is it possible to take automatically a “screenshot” of my selected feature in QGIS using Python?

I am implementing a tool which allows the user to create a profile of a feature (in my case urban parcels). Is it possible to automatically take a screenshot of this feature (displayed in a QGIS ...
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1answer
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Is there a way to access QGIS plugins in Python?

Is there a way to access QGIS plugins in Python? I'd like to write a script to do some geoprocessing, and I'd like to use the clip, regular points and convex hull tools in fTools, as well as the Road ...