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

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47
votes
2answers
23k views

How to get “.GDB” (Esri File Geodatabase) support in Quantum GIS (osgeo4w - qgis)

Following questions: Open Source Tool capable of Reading .gdb? How to access file geodatabase in Qgis? How to get FGDB support in GDAL 1.9 without compiling? I have spent around 2 days to find the ...
44
votes
4answers
16k views

How to build effective heat-maps?

Using ArcGIS, QuantumGIS, Grass, and/or GVSIG What are some of the tools and processes involved in building effective heat maps? What are the plugins involved? What are the major data requirements? ...
37
votes
11answers
5k views

Where can I find QGIS tutorials and resources?

After several recommendations, I thought I'd familiarize myself with the capabilities of QGIS. I downloaded the program, but apart from basic loading of data, I got lost (the help file wasn't much ...
32
votes
8answers
11k views

QGIS and gvSIG comparison

Many debutant GIS users are asking me which one is better QGIS or gvSIG. Since I use Qgis and I don't have any experience in gvSIG, I aways say that both are very nice softwares and the chose is a ...
31
votes
4answers
6k views

Migrate from ArcGIS to QGIS?

This is my first visit to and first question on this site, I hope this newbie question is suitable here. Our lab has about 10 projects in ArcGIS 9 (a couple are made in ArcGIS 10) that includes the ...
25
votes
2answers
6k views

How to style beautiful road maps with QGIS?

I am trying to design a beautiful map using Qgis. As I'm a software developer not a designer, I was hoping that this will be easy, but it isn't! There is a similar question here Qgis tutorials and ...
22
votes
3answers
5k views

Visualising WKT geometry string in QGIS

A very simple question: Is there a simple tool in QGIS to graphically visualise geometry formatted as text? Example geometry: "POLYGON((571178 6337246,571178 6402217,598061 6402217,598061 ...
22
votes
3answers
21k views

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?
22
votes
3answers
4k views

How to smooth a DEM?

I have a SRTM DEM and I want to create a shaded relief from it. I created the shaded relief in GRASS and the result is very nice, but a little rough becouse the area is near flat and the DEM is 90m in ...
22
votes
3answers
4k views

How to generate Tiles with QGIS

Is it possible to generate map tiles from QGIS? I guess QGIS Server must have a way to do it, but is there a way to just generate the tiles and save them to disk? With the new symbology renderer and ...
21
votes
3answers
3k views

What do I need to know, to develop a plugin for QGIS?

I wish to develop a simple plugin for QGIS, which will open some data, and some specific processing. I have quite a it of development experience with ESRI's Arcojects, but haven't developed with QGIS ...
21
votes
4answers
2k views

How to calculate terrain Curvature?

I have an elevation raster and I would like to get some basic terrain variables, such as slope, ruggedness, aspect or curvature. The problem is that I don't seem to have the possibility to calculate ...
21
votes
1answer
628 views

What does the adoption of Python by NVIDIA for GPGPU mean for GIS?

Today NVIDIA announced support for the Python language on its flavor of GPGPU (CUDA). Manifold GIS uses CUDA to enable some accelerated raster operations but it is not a programmable environment and ...
20
votes
2answers
16k views

How to calculate polygon areas in QGIS?

Hi I would like to simply calculate areas of a area-shape file in square meters or in acres (ha). I didn't find that functionality in the vector tools. Could anyone here help me with that?
20
votes
3answers
6k views

How to make a spatial view in PostGIS and add it as a layer in QGIS?

In PostGIS 2.0, what is the most efficient way to create a spatially enabled view that is viewable in QGIS? I followed the context of Part 2 of @Mike Toews answer to this question, and the view ...
20
votes
5answers
3k views

How to identify clusters in vector point data?

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. ...
19
votes
3answers
4k views

Optimal video cards for GIS programs

I recently purchased a Dell XPS-8300 (i7-2600|16 GB DDR3 RAM|64-bit Windows7) which I intend to use primarily for GIS programs. I bought a refurbished model because it was much cheaper and because I ...
19
votes
7answers
14k views

Removing small spaces between polygons

I have a set of polygons representing administrative districts. The districts were digitized by hand, and there are small spaces between polygons where the polygons should be touching. How can I ...
19
votes
6answers
3k views

Creating a small web-mapping/map-tiling service

I am looking for a small-scale and easy way to present one or more polygon shapefiles online (on a municipal website without any existing map-server infrastructure, to be precise). Right now, I'm ...
19
votes
4answers
3k views

Is there any model builder in QGIS or other open source GIS?

Like the model builder in ArcGIS Desktop to run simultaneous geoprocessing tools, is there any model builder available in QGIS or an open source GIS software.
19
votes
5answers
4k views

How do I get the best print quality from QGIS (and is Arc better)?

QGIS exceeds my expectations by a country mile. I am impressed. But; I work with people who use Arc and they have found the best resolution output images are made by creating PDFs. They tell me that ...
18
votes
3answers
3k views

How can I calculate the average width of a polygon?

I'm interested in examining the average width of a polygon that represents the road surface. I also have the road centerline as a vector (which is sometimes not exactly in the center). In this example ...
18
votes
2answers
7k views

How to convert an .mxd file to a .qgs file?

I recently tried to use QuantumGIS and I wondered if you can turn in a draft format ESRI mxd loadable qgs. This would avoid thematize the entire project. Thanks for your help.
18
votes
3answers
2k 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 ...
18
votes
2answers
13k views

How to access file geodatabase in Qgis? [duplicate]

How does one access data from an Esri file geodatabase in Quantum GIS? I've seen snippets of conversation that indicate it's possible with qgis 1.7+ and gdal 1.9+ but no clear recipe. I recognize ...
17
votes
3answers
267 views

Python literature relevant to QGIS

Python for ArcGIS is a book that I have been looking at. Does anyone know if this would be applicable in QGIS? I am not looking to write application/plugins, simply get better at understanding ...
17
votes
1answer
9k views

How to install a QGIS plugin when offline?

Due to various IT policies at my workplace, QGIS is installed on a machine that is not connected to the internet. I wish to install a couple of QGIS plugins on this system. I have downloaded the ...
17
votes
2answers
5k 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 ...
17
votes
3answers
13k views

How to clip a raster with vector boundaries?

I am using QGIS. I would like to clip a raster precipitation layer using an admin boundary layer that is vector data. However the geoprocessing tools seem to be usable only for vector data. How can ...
17
votes
1answer
704 views

Gravity/Huff model tools

I am looking for a way to simulate a gravity model using a point-based layer. All my points are assigned a z-value and the higher this value, the larger is their "sphere of influence". This influence ...
16
votes
3answers
2k views

How can I switch line direction in QGIS?

Something that is hopefully pretty easy. I would like to be able to swap the direction of a polyline/line in QGIS. I made a custom tool to do this in MapInfo a couple of years ago, however I can't ...
16
votes
1answer
3k views

How to define new custom projections in QGIS?

I'm trying to define a projection in QGIS. I want to add North America Albers Equal Area Conic. From the spatialreference site I copied the proj4 line: +proj=aea +lat_1=20 +lat_2=60 +lat_0=40 ...
16
votes
1answer
1k views

What's the status of Postgis 2.0 topology support in QGIS?

Having followed the Postgis developments over the past 6 months I have noticed a bunch of features which seem to be incredibly cool especially in the area of topologies and associating calculations on ...
16
votes
1answer
176 views

Can we create views over a raster table in Postgis2.0?

Is it possible to create PostgreSQL views over a table that contains raster data? I have succeeded in creating the view but the entry in raster_columns is not correct (all the raster info is ...
16
votes
1answer
380 views

How to create a QGIS Installer for Windows with GUI customization?

I'm trying to build a custom QGIS installer for Windows with a stripped down GUI. I customized the GUI using the customization function of QGis and saved it as a .ini file. The question now is: How ...
16
votes
4answers
587 views

How to do kernel density estimation with a physical barrier/ boundary in QGIS?

Does anyone know of a programme that will allow kernelling that takes a boundary into account in its calculation rather than simply masking areas that are impossible? So far I have found: GME add on ...
15
votes
4answers
340 views

Is the term “Quantum GIS” trademarked?

We need to link to Quantum GIS on a major official website. My legal department asks me if "Quantum GIS" is trademarked. Is it? Thanks -- Alex
15
votes
3answers
2k views

Visual Impact Assessment in QGIS or GRASS

Is it possible using QGIS or GRASS to perform a Zone of Visual Impact assessment? E.g. where can a 100m high structure be seen at a viewing height of 1.8m within 30km, taking into account elevation ...
14
votes
9answers
19k views

How to install QGIS on Ubuntu 12.04?

Has anyone had any luck with getting QGIS working on Ubuntu 12.04? I have tried the stable and unstable versions and with not luck. I also get the following: "Some packages could not be installed. ...
14
votes
6answers
5k views

Why is the performance speed between ArcGIS and QGIS so different?

Ok I am not a programmer but a prolific GIS user. I know that QGIS is written in C++ and ArcGIS in ??? but for most of my tasks lately I always try to use QGIS not only because it is free but due to ...
14
votes
6answers
4k views

Generate points that lie inside polygon

I have polygon feature and want to be able to generate points inside it. I need this for one classification task. Generating random points until one is inside the polygon wouldn't work because it's ...
14
votes
4answers
6k views

Join non-spatial CSV to spatial data in QGIS

I have a csv which has postcode data in a field, but it is non-spatial e.g. no Easting and Northing. I have a shapefile with postcode in a field and some additional data. I want to join the csv with ...
14
votes
4answers
2k views

What are data visualization and analyses pros/cons of QGIS over ArcGIS?

Many of my colleagues use GIS on a very sporadic basis for simple data visualization and basic analysis (clipping, buffering, etc.) and I am hoping to transition these non-core GIS people to QGIS so ...
14
votes
6answers
3k views

A SQL console in QGIS

I know QGIS comes with its field calculator, which is not bad. It also comes with ftools which permits several operations on geometry and attributes. But we often need more control and I haven't seen ...
14
votes
3answers
333 views

Is it possible to use symbols instead of colours to visualise raster cell values?

I have a raster image (GeoTIFF) with integer values. I know how to visualise raster values in QGIS using colormaps or similar, but I would like to assign symbols to each colour value instead - just ...
14
votes
6answers
3k views

What's the best way to produce a density map from weighted points in QGIS?

I'd really like to repeat the functionality of the ArcGIS Kernel Density tool - how could I do that? I would like to limit answers to easy-to-install free-and-open-source software – i.e. QGIS ...
14
votes
2answers
3k views

What's the relation between QGIS and GRASS?

I have been working with GIS and remote sensing in an university and professional environment some ten years ago (ArcInfo etc), so I have some experience even though somewhat outdated Right now I am ...
14
votes
5answers
1k views

Find pseudo nodes in free GIS software

Software gvSIG OA Digital Edition 2010 have tools topology for finding pseudo nodes in linear geometry. I set cluster tolerance 0.00002 and maximum number of errors -10000 for 20000 link count linear ...
14
votes
3answers
5k views

How do I load OSM vector data in QGIS 2.x?

In QGIS 1.8 I used the openstreetmap plugin to request data from the server, or open a .osm XML file, which produced 3 layers (polygons, polylines and points) in QGIS. This was great (give or take the ...
14
votes
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 ...