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

learn more… | top users | synonyms (1)

0
votes
0answers
177 views

How do I use the new USGS topo WM(T)S in QGIS?

The WMS link for "Scanned Topo Maps from USA Topo" in http://viewer.nationalmap.gov/example/services/serviceList.html no longer works (HTTP 400). ...
2
votes
1answer
233 views

How do I plot a line on a map, or obtain the latitude and longitude coordinates of such a line, that is 120km north of the US-Canada border?

How do I plot a line on a map, or obtain the latitude and longitude coordinates of such a line, that is 120km north of the US-Canada border, including parts of the border that cross water? (I managed ...
0
votes
2answers
122 views

Output map of only 50m-100m contours [closed]

I´ve got the "OS Terrain 50" contours/spot-heights dataset. I would like to output a series of maps with everything above 0m, 50m, 100m etc. from a region. I know almost nothing about GIS, but have a ...
2
votes
1answer
176 views

How to creat multiple rings between two circular buffers?

I am working with mathematical-ecological modeling and I am also a new user of QGIS Software. First I am creating 3 circular buffers with same center (shape center) covering a region with roads (shape ...
3
votes
1answer
327 views

Converting models from QGIS to Python scripts?

I want to automate some tools for QGIS 2.0.2 using Python. Previously I have used ArcMap for automating tools and now i want to use QGIS. In ArcMap I used the ModelBuilder, and more specifically the ...
3
votes
2answers
460 views

TIF format to view a vegetation Map with QGIS

I'm a new user of QGIS and I'm trying to view a map present in an online GIS dataset. There are several formats for this dataset and one of them is a TIF folder with several files: .tif, .tif.aux, ...
2
votes
5answers
2k views

Unable to install ECW support on lubuntu 14.04

I try unsuccessfully to install the ECW support (mainly to use ECW file in QGIS 2.2). We attempt to follow and adapt the howto provided by makina-corpus. My first supprise was the repository ...
1
vote
0answers
54 views

PostGIS automatically creating geometries after importing using QGIS DB Manager

I have a shapefile consisting of linestrings, in which some of the features have null geometry. Yet, after importing it to PostGIS, using QGIS' DB Manager, a geometry is created for those features ...
0
votes
1answer
184 views

Add GPS tracks directly to a PostGIS table

Disclaimer: I am a total GIS newb and I have a use case I have not seen elsewhere. Background: I drive country roads looking for old building, cemeteries, school houses, etc and I record the ...
0
votes
1answer
74 views

Is it possible to change the style on a WMS layer using QGIS?

Apologies from a QGIS beginner but I have added a WMS layer of polygons to fill in the gaps of an existing data set I have. the problem is that I want all of this data to have the same style (colour ...
-1
votes
1answer
66 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
321 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
157 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
78 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
749 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
70 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
78 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
37 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
55 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 ...
1
vote
2answers
2k 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
240 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
204 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
356 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
80 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
181 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
77 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
73 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 ...
9
votes
3answers
3k 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
268 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
148 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
286 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
343 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 ...
2
votes
1answer
140 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
63 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
290 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
141 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
80 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
20 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 ...
1
vote
1answer
269 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
79 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 ...
14
votes
1answer
392 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
148 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
304 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
96 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
336 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
93 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
442 views

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

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
607 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
212 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
82 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?