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

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1answer
150 views

Applying styles to categorized layer using QGIS

Apologies if this is an easy question from a QGIS novice but I have categorised a layer so I can attach reference numbers and names to the various points but I would like all the points to have the ...
1
vote
1answer
591 views

Intersect between polygonal shapefiles error

I'm encountering a problem when I try to intersect two different shapefiles. They are all new shapefiles I created to descibe the land cover and the land use of a city. The problem occurs when I ...
0
votes
1answer
304 views

“ImportError: No module named fiona” (post-installation of package)

I'm in need of the Fiona and Shapely modules to develop a QGIS 2 plugin, and thus downloaded them from http://www.lfd.uci.edu/~gohlke/pythonlibs/#gdal and installed them. I have no trouble importing ...
1
vote
0answers
103 views

Graphical Modeler to rotate points based on line layer azimuth

I am trying to create a model using the QGIS 2.0 Processing Toolbox graphical model to replicate the process described in this thread: How to horizontally align irregularly shaped point symbol to ...
2
votes
1answer
2k views

How to merge hundreds of vector layers and sum attributes in QGIS?

I'm still at a fairly beginner level with QGIS and I've been banging my head against the wall trying to figure this out, so I would like to turn here for the internetz help. I am trying to construct ...
2
votes
1answer
98 views

Adding GPS tracking data from Excel into QGIS

Sorry if this is an easy question! I have added GPS points in QGIS however all of them are the same colour. I want the points to be coloured differently for each individual. How do I do this? Thank ...
3
votes
1answer
195 views

How to align an HDF layer

Forgive me, but I am completely new to GIS. I am using QGIS. I have a raster layer (HDF format) that does not align with other layers. All layers are projected WGS84 (EPSG:4326) and still the problem ...
1
vote
1answer
48 views

How to create a map from the highest and lowest average values [closed]

Anybody can help me, how to generate the map from assumption data. I have 100 points data (from GPS reading) showing the location of the bee nest. Unfortunately there is no record on how much volume ...
2
votes
1answer
82 views

unable to draw polygon without attribute window popping up?

I'm fairly new to QGIS and an trying to draw a polygon via "Adding Feature". When I make the first left click to start, the attribute window pops up instead of letting me continue on with additional ...
2
votes
2answers
8k views

Drawing tools to add circles, arrows, lines for QGIS?

I'm pretty new in QGIS and i'm searching a drawing tool like it is possible to find in microsoft word or excel. I search something very user friendly (for dummies!) to add circles, arrows, lines... ...
1
vote
1answer
419 views

Auto increment a new column using Model Builder Field Calculator in QGIS?

I am making a model which requires creating a grid and clipping various layers to it. Using the Create grid function does not provide an ID column, instead it creates 2 columns: "longitude" and ...
1
vote
0answers
289 views

qgis html annotation - scale dependent rendering?

In the QGIS 2.2 map composer, I have a large map at a certain scale (let's say 1:25000) and an inset map that is an enlargement of part of the main map (let's say 1:12500). When adding html ...
0
votes
3answers
416 views

Any updates on problems with loading ESRI FileGDBs in QGIS 2.2?

There are many posts in different forums about people having trouble reading File GDBs in QGIS 2.2, but no real solutions. Is there any word on a resolution to this problem? I am using QGIS 2.2 ...
1
vote
3answers
118 views

How can I apply multiple expressions to a field in QGIS?

I'm working expanding abbreviated names in a shapefile. I have written the following expansions, and would like to learn how to write a field expression that would do many expansions in one. replace( ...
2
votes
2answers
360 views

PyQGIS: How to send signal if layer is currently in edit mode

I'm looking for a way to send a signal if a layer is in editing mode. I tried editingStarted(), but it wasn't working. I'd like to do something along the lines of the what I have below, but can't find ...
1
vote
1answer
106 views

Auto generate map from natural earth data with QGIS or other utility

I'm looking at natural earth data to generate each country and save it as a png. What I'm using is: 10m_populated_places, 10m_admin_0_countries and 10m_land. The populates places is the first layer, ...
2
votes
1answer
86 views

Finding Code in QGIS Select Features Toolset

Can anyone tell me in what directory the pre-installed Python scripts for the QGIS selection tools (i.e., Select by Point, Select by Polygon) are found? I am using on a Windows 7 installation of QGIS ...
14
votes
6answers
9k 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 ...
6
votes
1answer
367 views

Why will QGIS only import the first 20 lines of my delimited text file?

I have a file of bird species and counts with Lat Long that I want to put into QGIS (2.0). However, when I add the file it only shows the first 20 entries (excluding the field titles). This is the ...
1
vote
2answers
242 views

Open mail client when clicking feature in Attribute Table

One of the attributes/features of my layer contains an email address. I'd like to be able to open the default mail client by clicking on the mail address from the Attribute Table. After some initial ...
1
vote
0answers
609 views

Converting GRIB to Geotiff with gdal_translate in Python

I want to extract each band from a GRIB (gridded binary from http://data-portal.ecmwf.int/data/d/interim_daily/) in a single Geotiff image. I´m using Python with gdal_translate in a QGIS backround, ...
1
vote
2answers
778 views

How can I create a pdf map at a high resolution while still keeping the file size manageable?

I have numerous layers in shapefile format that contain a lot of data across a large area. I am trying to create a .pdf file that shows all of the area and I want it to be in good quality, so that ...
3
votes
1answer
279 views

How to implement 1:n joins with string attribute concatenation?

I have a question concerning pyQGIS. I'm a QGIS long-time (self-learned) user, but just a pyQGIS newbie. I want to implement 1:n spatial join with attribute concatenation in the table. I have a vector ...
1
vote
1answer
68 views

Problem with QGIS 2.2 joins between shp and csv

Didn't see question like this asked, so... I've joined csv to shp file and everythings seems ok. I've modified attribute form so that fields from joined csv appears in there. So far so good- it's ...
2
votes
1answer
505 views

How do I add a column in an attribute table using QGIS graphical modeler?

I have started to make a model in QGIS 2.2 graphical modeler. I have made a buffer around a polyline and used it to clip a polygon layer. So far i t works. But the next step is to add a new column ...
0
votes
0answers
241 views

QGIS: field calculator is not working with shapefile created manually

I have an issue the field calculator of GIS 2.2 field calculator. I've not encounter problem to update values with the field calculator (I'm using the $row_num function) if the shapefile was created ...
1
vote
1answer
122 views

Unable to select FLOAT precision when adding column

I'm trying to do the lessons in the training-manual at qgis.org. I,m having some problems with 3.3 Ratio Classification ...
0
votes
0answers
38 views

QGIS 2.0.1 crashes by starting the app

I have QGIS Dufour for Snow Leopard on a Macbook. It worked good until I tried to install a plugin from Garmin an the program crashed. Since them it crashes every time I try to start it. There is ...
2
votes
1answer
546 views

How to use Threads in PyQgis, mainly to keep UI active?

I'm trying to develop a plugin, which does heavy computations and as a result, user interface becomes inactive. I know that I should use threads to keep the UI alive (specifically, I have a progress ...
0
votes
1answer
91 views

Where can I find topology-related algorithms used in QGIS?

I have shapefile with polygons and I test topology - overlaps, duplicates and gaps. I tested it in QGIS and now I have to describe algorithms, which uses QGIS for this rules. I must write research ...
15
votes
1answer
478 views

How to query OSM for all beaches facing west? - QGIS preferred

I want to identify all beaches on this planet (or a given subset of it) that are facing westwards (+/- 20-30 degrees). My idea is to use OSM as the data source. Extracting all polygons that have the ...
0
votes
1answer
203 views

cut square from geotiff

i want to make a 3d modell out of the mount everest and some other mountains. what i need therefore is a 14km² square around the peak from the mountain. so basically i use qgis to extract the area ...
1
vote
3answers
657 views

How to add columns with x/y data to Spatialite Layer? [closed]

I´m new here and I am also quite new at working with QGIS. My Spatialite Database looks like this (arch_locations.sqlite) Fields: pkuid short_ID name geometry I´d also like to have two additional ...
1
vote
1answer
156 views

How to batch interpolate many shp´s to DEM

Here´s the problem: I have about 40 shapefiles of contourlines (type line) and I need to interpolate them to create DEM's (tiff, or better some grid format). To do so, some batch scripting would be ...
3
votes
2answers
776 views

How to convert a point layer to a raster grid that shows the frequency of points per cell in QGIS

I have a point layer that shows the distribution of a species. Is it possible in QGIS to convert this point layer to a raster grid in which the value of each cell corresponds with the amount of points ...
2
votes
1answer
116 views

How to edit a QGIS plugin GUI?

I have inherited a QGIS system from a former employee and my predecessor built a custom plugin for it. I now need to remove a single checkbox option completely from the UI for this plugin. Is there a ...
1
vote
0answers
611 views

Error when kriging in SAGA: grid file could not be opened [duplicate]

I have a point and a polygon vector shape (shapes) which I want to interpolate by using the saga tool "Ordinary Kriging". I always get the following error message: Oooops! The following output ...
3
votes
3answers
1k views

Black/white hatching pattern fills in QGis

I am looking to replicate black & white maps in QGis, using hatching patterns and greyscales to indicate different categories of a continuous variable (example below). It is ...
3
votes
1answer
310 views

More than one WMS layer in QGIS

I have a problem when using WMS layers. I'm usin QGIS. I'm loading a WMS layer containing some aerial images. And then on top of it another WMS layer that contains information of the city, boundaries ...
0
votes
1answer
86 views

How to list..only the Field names for a group of files in a folder?

I am having...for eg, 27 files in a folder (may be a shp or tab). Is it possible to list the Field_Names (ID, Type, Date, Allotment, etc..) alone of all those 27 files in a csv format or xls format?
3
votes
0answers
93 views

How to include external libraries with my QGIS plugin? [duplicate]

I'm developing a plugin which makes use of "networkx" library extensively. However, networkx is not part of Python libraries pre-installed in QGIS. Is there a way to include this library with my ...
0
votes
2answers
121 views

QGIS Connection PostGIS and shapefile

I'm working on QGIS with a database created in PostGIS and a shapefile. Inside the database, I have geometry type data about location of some points, instead on the shapefile there some selected ...
0
votes
1answer
519 views

JPEG base map doesn't match shapefile locations

Relative Newbie Question: I have Civil War earthworks tied to the State Plane Coordinate system with a jpeg of the terrain as a 100k scale USGS Quad of the area that is not georeferenced. When I work ...
1
vote
1answer
144 views

Overlap or intersect two choropleth [closed]

I have two choropleth of the same area but with different concentration data and I need to overlap them. My aim is to highlight the areas of intersection between the points with the highest ...
2
votes
2answers
914 views

How to calculate distance in meter between QgsPoint objects in PyQgis?

I tried to calculate distance between QgsPoint objects in qgis, i used QgsPoint StartPoint.sqrDist(EndPoint). but i don't find an expected result, i also tried import math ...
1
vote
1answer
235 views

How to remove thin lines and small points from qgis raster

I want to digitize the roads of a raster map to vector format using QGIS and GDAL preferably. By using the Raster Calculator I have been able to extract the roads and contour-lines from the raster to ...
2
votes
1answer
1k views

How do I use 'model builder' in QGIS 2.2?

I am trying to learn how to use the 'model builder' in QGIS 2.2. I have used model builder in ArcGIS, but I don't understand how to do it in QGIS 2.2? What I want to do is to make buffers, clip ...
1
vote
1answer
319 views

How can I create an animation with raster data in qgis?

I have 4 raster images showing different coniditions of air flow distribution at different times. I'd like to create an animation to show the change from image 1 to image 4. How can I do this? I tried ...
3
votes
2answers
269 views

Converted GPX file has null values in open attributes

I'm an absolute newbie but I think I'm doing this right. I've got a bunch of .fit files from my garmin. I can use GPSBabel to manually convert these to GPX XML and the map looks fine after the ...
2
votes
1answer
588 views

How to populate a combobox with layers in TOC?

I am developing a plugin, and I want user to select one of the loaded layers from a combobox. I've already coded this much: self.dlg.show() layerlist = [] self.dlg.ui.layerCombo.clear() # ...