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

learn more… | top users | synonyms (1)

1
vote
2answers
452 views

How to mask out features outside of the Coverage Layer for Atlas plugin? [duplicate]

Using the Atlas plugin for qGIS how do I set the coverage so that it will only highlight the feature(s) I want but still show the surrounding features as grayed out areas? This would have been easy ...
1
vote
2answers
2k views

Adding .e00 data into QGIS

I wonder if anyone can advise me on how to go about adding .e00 data into my QGIS project. I'd be very grateful for any advice, or a hint on where to find it. Thanks TVZ
1
vote
1answer
2k views

QGIS: creating lines from starting to arrival points?

Is it possible in QGIS to create lines from a table storing the X,Y-coordinates of starting and arrival points? So that a line.shp is automatically created? Or exists a plugin to achieve that? ...
1
vote
1answer
3k views

How to convert a regular point grid to raster? [duplicate]

Possible Duplicate: How to convert a point grid to a raster? I´d like to convert a regular grid (25 meter) of points (XYZ) to a raster. I have tried the GRASS-tool r.in.xyz but I always get ...
1
vote
1answer
498 views

how to open layers with multiple geometry types in qgis?

I recently had some difficulties opening some MapInfo TAB vector layers in QGIS because each MapInfo layer contained two different geometry types: point and line. The MapInfo layers had originally ...
1
vote
0answers
2k views

Error when importing shapefile to Postgis database

I was trying to import shp to postgis database and i get the following error: Importing with configuration: adresy92, public, geom, C:\Users\tomek\Desktop\adresy92, mode=c, dump=1, simple=0, ...
1
vote
2answers
981 views

Interpolation of contours (from one “main-contour-shapefile”)

I calculated, that the best and smalest possible äquidistance (equidistant) for my map is 30m. After I generlized my DHM, I extracted contours of a intervall of 30m and smoothed them. Now I have my ...
1
vote
1answer
808 views

Last edited information missing when used QGIS - Dxf to Shp

I am doing as constructed drawings which require the information to be in a GIS system and more specifically drainage as constructed drawings. I must have a separate file for Pipes and Pits. First I ...
0
votes
1answer
138 views

How to trigger a QGIS action when a plugin button is clicked?

I tried calling the select free hand tool by below snippet of code. iface.actionSelectFreehand().trigger() I dnt have any idea how to call this when i am pressing a button in GUI. my gui is ...
0
votes
1answer
256 views

QGIS: Multiply Raster Value with Pixel size

i'm working on a map with population densities. My raster data contains values as [People/square meter] for each cell. I have per capita values of energy demand etc. which I want to multiply with the ...
0
votes
1answer
129 views

Blank Shapefile output?

When executing the following command string in the active browser, Qgis projects the triangle polygon and associated attribute table correctly. Upon reopening the shapefile in a new browser, the ...
0
votes
0answers
112 views

Issues creating slope raster layer from a point layer

I'm trying to create a slope raster layer using QGIS 2.0 on Windows XP. I started with a points layer with the Z elevation attribute. I then used the interpolation plugin to create a DEM. But, ...
0
votes
2answers
157 views

Calculate length of line across zones with at least m accuracy

I have created lines between multiple points that are across MGA 54 and 55S (EPSG 28355). I am trying to calculate the distance between points but different methods give different answers (~1km ...
0
votes
1answer
1k views

Can not make qgis.db private copy

I've just installed Qgis 2.0.1 and the above error message appears. Does anyone know how to resolve this problem? I think I need to change the permissions of the relevant folder, but I'm not ...
0
votes
2answers
123 views

How can I delete dangling paths after merging features

In my previous question I've asked how to can I merge different polygons while converting to GeoJSON and TopoJSON. After a day of researching I've realized that, rather trying to do it command line, ...
0
votes
1answer
1k views

How can I create a line with three points with Python in QGIS?

I'm new to Python and I'm having some dificulties. I want to create a simple layer with a line in the console of QGIS with Python. How can I do that?
0
votes
2answers
294 views

How to rotate (svg) symbols in QGIS map composer to match map rotation?

Because of my thesis layout requirements, I have to rotate 270° some of my maps in composer. There are (many) svg smbols (icons), and they are rotated as well. I would like to (non-)rotate them in ...
-1
votes
3answers
12k views

How to publish my map on the web? [closed]

I want to publish my map is created in QGIS 1.7.4 version on to the web.Can u pls suggest me how to publish the map with proper documentaion and screen shots if possible?
12
votes
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 ...
11
votes
4answers
1k views

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 ...
11
votes
3answers
853 views

Contours: Interrupt contour lines beneath a elevation number

Is there a way to interrupt a contour line beneath a elevation number? Thanks!
11
votes
1answer
301 views

How to create a label combining different font sizes or types?

I would like to place the elevation-number of a point in a different front size and centred under its name: Is that possible? (That is my actual labeling: label || '\n' || elevation) Thanks!
10
votes
1answer
559 views

PyQGIS file lock release

I was wondering what triggers the release of file locks in pyQGIS? I am trying to delete a few data sources (used temporarily) by calling QgsVectorFileWriter.deleteShapeFile, but I have to quit QGIS ...
10
votes
2answers
2k views

What is the standard Mercator projection?

I'm using QGIS in order to re-project a shapefile I have into "Mercator" so that something like protoviz understands my co-ordinates. Protoviz tells me "Mercator" ...
9
votes
3answers
5k views

QGIS, Postgis: Geometry type does not match column type

I'm trying to import some polygon shapefiles to Postgis in QGIS via SPIT. One of them can't be imported and returns this error: ERROR: Geometry type (Polygon) does not match column type ...
9
votes
1answer
490 views

Why are some columns not recognized as numeric even though I have a CSVT?

I have problems importing a .csv file. Some Values of the file are not supposed to be formated in text style, but in number style, thus i created an additional .csvt file like explained here. Both ...
8
votes
2answers
546 views

Finding polygons without right angles using Open Source GIS or ArcGIS for Desktop?

Now we are digitizing some buildings in specified area. The obligatory rule for this work - in most cases buildings should have right angles. We are using QGIS with CAD tools for this work but ...
8
votes
3answers
5k views

How to delete multiple selected polygons at once?

I'm new at this, a novice at best. I'm using QGIS 1.7.3. I simply want to select a large number of polygons on screen and hit the delete key to delete them and resave the shapefile. Can this be done?
8
votes
3answers
887 views

Best way to manage large number of geoTiff rasters

I have around 2-3000 1-bit geoTiffs of size 11000x9400. Color 0 should be transparent, and QGis gets it wrong in the first place, so I used a .vrt file to set all the parameters in one single place. ...
7
votes
1answer
268 views

Find maximum radius of circle that will fit within an irregular polygon?

I have a problem which I think could be handled by using the Zonal Geometry tool in the ArcGIS Spatial Analyst toolbox. However I do not have a license for Spatial Analyst, so I am searching for an ...
7
votes
4answers
3k views

How do I open personal geodatabase in QGIS 2.0?

Good afternoon. I am trying to use an ArcGIS (10.2) personal database MDB as a container for data to pass to a QGIS user. I formerly used QGIS 1.8 for Mac OSX, and after some fiddling around, I was ...
7
votes
2answers
269 views

How can I force text to appear underneath other layers in QGIS?

To emphasise one particular polygon area, I have used rule-based styles (QGIS) to apply a 50% transparency white fill to every polygon but the one I am interested in. This polygon layer is above all ...
7
votes
2answers
3k views

How to split an irregular polygon into equal areas?

I am a surveyor and use QGIS for maintaining soil test records on civil projects and am constantly provided with test lot area or number of lots required. These are more often than not irregular in ...
7
votes
1answer
783 views

QGIS: subtypes and domains like in ArcGIS?

s there a opportunity to use subtypes and domains in QGIS (Desktop 1.8.0) like the way you use in ArcGIS? I´m specially interested in the possibility of dependencies between subtypes and domains: not ...
7
votes
0answers
71 views

How can I automatically split a spatial layer to a grid [duplicate]

Possible Duplicate: Divide vector in equal smaller parts in QGIS or similar I am a software engineer and the company I work for has a project that needs some spatial data manipulation in ...
7
votes
1answer
235 views

Why is there a black hole in the Heatmap?

After running the Heatmap tool in QGIS I like to color the geoTiff according to my wishes. Using Psuedo color works fine, but it leaves me with no options, as type of color scheme or transparancy on ...
7
votes
1answer
1k views

Is there a way to automatically snap loose points of lines to close by vertices with Quantum GIS?

I have a vector layer of lines that were drawn with the snapping option off. I need to have them snapped but, there are hundreds of lines. Is there any solution to do this automatically or ...
7
votes
3answers
3k views

Create Shapefile with auto increment primary key in QGIS

Is there a way to create an auto increment primary key column when creating a new Shapefile in QGIS?
6
votes
2answers
315 views

QGIS area calculation differs when on the fly CRS transformation enabled

When I open QGIS, add the layer, and calculate the areas of the shapefile via field calculator I get a different area than when I open QGIS and check "Enable on the fly CRS transformation" and ...
6
votes
1answer
196 views

Label placement on rotated map in QGIS

I'm a newbie to GIS and QGIS (please be nice to me). I'm working on a map for a garden/arboretum catalogue using QGIS 2.6.1. The arboretum has been surveyed using GPS, and the specimen trees and ...
6
votes
2answers
639 views

ESRI Personal Geodatabases in QGIS 2.6

I am having an issue loading any ESRI personal geodatabase in QGIS 2.6. I have a number of files that worked in QGIS 2.4 and having done the upgrade I can't open them in 2.6. I have tried this with ...
6
votes
2answers
280 views

Wrong $area from field calculator (QGIS)

The area of the polygons in a layer, calculated by the field calculator with "$area" is wrong (much too big) for some polygons. If I draw the concerned polygon again, the area is calculated correctly. ...
6
votes
3answers
291 views

How to find out if OpenStreetMaps contains low emission zones?

Since I never really digged into the data contained in OpenStreetMap I ask myself what would be the recommended way to identify layers or tags within the overall data. In my current use case I want to ...
6
votes
1answer
968 views

How do I convert a .dxf to a .shp containing a field with height information in QGIS?

I received two .dxf for my project that represent my area of interest. One of them contains buildings, the other one terrain elevation. They both are 3D. I can convert them to shapefiles successfully ...
6
votes
1answer
2k views

How does Flow Mapper Plugin work?

I downloaded the Flowmapper plugin for Qgis and I can't seem to find any information on how it is supposed to work... Also the text seems to cut-off and not fully showing for the input fields so I'm ...
6
votes
2answers
2k views

Why do my Shapefiles not align correctly?

First: I'll summarize what I understand so far so please confirm or correct me. When On-the-Fly is selected a layer is re-projected from that of the layer's CRS to that of the project CRS, IF ...
6
votes
1answer
247 views

How to consecutively number polygons from north to south following a polyline?

I have a shapefile (polygon) with a large number of polygons (roughly 10,000) that form a narrow but very long belt that windes through half a country and another shapefile (polyline) that represents ...
6
votes
1answer
133 views

How to change all values in a field in one operation?

I am setting up a couple of shapefiles with text x, text y, text rotation and text size fields in order to utilize the labeling toolbar where I can move and rotate labels. I would like the values for ...
6
votes
2answers
322 views

How do I compute v.kernel maps in less than 16 hours?

I am using the GRASS GIS 6.4.2 bundled with QGIS 1.8.0, using a PostGIS dataset exported via v.in.org.qgis from QGIS, to create kernel density maps. The layer has 738,288 points. My problem is the ...
6
votes
2answers
6k views

Create a polygon layer from point data

I'm currently using QGIS 1.8.0 I would like to create a polygon layer from a point dataset, where the size of the polygons relates to the resolution of the grid reference. The ultimate aim would be ...