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

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3
votes
1answer
73 views

How to transform XYZ Raster from WGS84 to UTM ED50 Zone 34

i'm trying to convert an XYZ file from WGS84 (lat/long) to UTM ED50 zone 34. Qgis can load the file as a raster, but i cant see a way of changing the coordinate system or exporting the results as an ...
2
votes
1answer
40 views

Previous shapefiles do not show in re-opened projects

I have previously drawn a lovely shapefile in a project - all saved...good job. I open the very same project and, although the background raster maps project fine, my shapefile will not show. Zooming ...
6
votes
3answers
181 views

Cutting out depth information in raster. Calculating volume in Qgis

I am trying to calculate habitat volume for around 30 fish stocks in Qgis. I have habitat areas (shape files) and Bathymetric information (.tif file). I believe I can calculate the entire volume of ...
1
vote
0answers
37 views

From QGIS to PostGIS [duplicate]

I want to download my data from QGIS to an existing table in Postgresql. I tried to use DB Manager, but the field add to existing table doesn't work. Maybe somebody knows what the problem is? Or is ...
2
votes
1answer
55 views

Why doesn't QGIS automatically find the new plugin update during startup?

I have done a plugin for QGIS and I made a repository (xml) for the end users to install it. Then, I made a new version and update also my repository file with the new one but Qgis doesn't ...
2
votes
1answer
45 views

Can i combine DXF, Google Earth Models, Shape Files and Rasters in QGIS?

I'm an architect, trying to bring a number of data sets together for use in a CAD package (AutoCAD). I have some georeferenced images (.jpg, .jgw.), Some model files downloaded from GoogleEarth (.kml ...
2
votes
1answer
67 views

how to load the QGIS openlayers_plugin in standalone python script (not the QGIS embedded python console)

if I try to load the openlayers plugin in a standalone application it always fails with False, although paths are set, and plugin shows available. (tested on Ubuntu 14.04, QGIS 2.4, python-2.7) ...
6
votes
1answer
174 views

How to auto-generate map images with different styles in QGIS?

I have got a simple map in QGIS, containing only 1 layer which consists of 10+ features. Now I need to (programmatically) generate about 200 different JPEG map images of the same area. Each map should ...
2
votes
1answer
54 views

Get feature data from lat long input QGIS

In QGIS, I have a polygon dataset with feature data. I would like to extract data from this dataset using a latitude and longitude. To be more clear, I have a list of 1000 coordinates. I would like ...
0
votes
1answer
43 views

QGIS Python - Convert the CRS of an in memory vector layer

In a python script of qgis I load layers from different datasources using the QgsVectorLayer() and the QgsRasterLayer() commands. The coordinate reference systems of the data sources differs. Since I ...
0
votes
0answers
5 views

PostGIS-Layer: sql query from style rules

I’m using PostGIS layers which are build from OSM-Data (osm2pgsql). Now I like to build a sql-query to filter the needed objects like "waterway" = 'river'. But in the layer-style I already have that ...
2
votes
1answer
61 views

QGIS 2.4 Heatmap Plugin Generates a Solid Black Map

I'm trying to generate a heatmap of vehicle-pedestrian collisions in Los Angeles using data taken from UC Berekely TIMS. TIMS provides an exhaustive database of traffic accidents involving injury in ...
0
votes
2answers
34 views

How can I efficiently divide a KML file by area, while using ogr2ogr?

I have a work process which uses an ogr2ogr text command to convert a MapInfo TAB file to a KML file. I'm very pleased with this because it maintains the original symbology (a simple 2 colour system ...
0
votes
1answer
41 views

Determining the slope of a DEM (SRTM-data) in QGIS

I'm new to QGIS and I have to calculate the slope of a DEM (I use srtm-data). I already detected the geoalgorithms toolbox and I also produced a raster layer with the slope using the tool "slope, ...
1
vote
2answers
54 views

Creating a plugin tutorial

I am looking for a tutorial of how to create a plugin for QGIS. I want a tutorial that: Explains about the latest version of QGIS Working in windows environment. adequate for absolute beginners and ...
1
vote
1answer
32 views

Problem with projection of Slovenian Shapefile in QGIS

I hope someone can help me for this: I'm doing my masters thesis in Slovenia (in the field of wildlife management), for this I got a Shapefile of slovenian data by the University. As a main layer, I ...
1
vote
0answers
42 views

New sound when running QGIS 2.4 [duplicate]

I used QGIS for a very long time. In the last version, there seems be a new sound (buzz) when the program is run. Does anybody know how we can remove this sound?
1
vote
1answer
36 views

Error importing raster into GRASS plugin in QGIS

I am trying to import a tiff raster file into GRASS however every time I do this the below error message comes up. I am using a custom CRS so I have tried changing it back to the default CRS but still ...
2
votes
2answers
49 views

Distance from centre point to other points using QGIS?

I have a question of something I actually thought was pretty simple...I have a few points around a centre point. Now I want to know the distance from each point to the centre point. Is it possible to ...
1
vote
1answer
32 views

Setting resolution for GRASS raster

I am trying to calculate volume using the GRASSplugin. I have my area information in vector format and my depth information in raster. I read that it is important to set the raster resolution before ...
2
votes
3answers
62 views

Saving project from QGIS to CD so it can be used on other computers?

For purpose of a project, I created a project in QGIS - aerophoto base and 3 layers. It works perfect on my computer, but if I save it on CD, the project doesent work on any other computer... I saved ...
3
votes
3answers
55 views

How to divide attribute table in map composer between 2 or more pages?

Does anyone know how to divide attribute table between 2 or more pages? In exported PDF it's unfortunately clipped.
2
votes
1answer
58 views

How to get a GML overlay on Google Maps?

Anyone know how to get a GML file to show as an overlay on Google Maps? To be honest I don't know my GML from my KML, or my ETRS89 from my WGS84, as this topic is completely new to me. A bit of ...
3
votes
1answer
31 views

How to change the color of vector layer of QGIS in api?

I'm using QGIS-2.4.0 api to develop app in C++. When I add a vector layer to the app, the vector map's color would be random. I used QgsFeatureRendererV2 to get the geometry type of the layer, my ...
1
vote
1answer
44 views

QGIS Web Client zoom and scale

I have a problem with setting up zoom levels and max/min scale in QGIS web client. It looks like that values used in GlobalOptions.js file does not apply. Right now ZOOM_LEVELS is 70, maxScale 50 and ...
3
votes
1answer
65 views

QGIS 2.4.0: dissolve tool renders artifacts / errors

The dissolve tool (vector>geoprocessing tools>dissolve) renders some artifacts on shapes with high number of polygons. I’m using a shapefile with 3222 polygons and I’m trying to dissolve it using the ...
2
votes
1answer
70 views

How to display distance in meters (km) and not in Decimal Degrees in QGIS 2.4?

I am a GIS beginner, and I have a question about how to get the distance between two points in meters instead of decimal degree. In QGIS 2.4 I have a project with two point layers (in WGS84). From ...
1
vote
1answer
31 views

QGIS vector layers do not match DEM?

I have a DEM (saved as a .tif) and, using QGIS, I want to clip the DEM using a vector mask. The function will not work. Am I missing critical step?
2
votes
2answers
55 views

Can GDAL fill elevation below a certain value?

I have several GeoTIFFs that I'm working with to create contours using gdal_contour. One of them crashes the utility. gdalinfo tells me that the computed min values for band 1 and 2 are ...
1
vote
1answer
89 views

Creating a World Population Density Map

I am trying to make a world population density Choropleth map (country level). The data I am using is publicly available on World Development Indicators website. Pretty much, I have an excel file ...
4
votes
1answer
109 views

Is there touch screen support in QGIS for Windows?

I have a new 2in1 PC (laptop and tablet). It would be very nice to navigate in QGIS using its touch screen I.e. zoom in and zoom out using double finger touch, like on a mobile phone, etc. Maybe ...
2
votes
4answers
83 views

QGIS Plugin with save settings dialog

I am writing on an update of the qgis2leaf plugin. It would be great to store the settings of the plugin UI (like which checkboxes are checked, which strings are used) in a separate file (like xml or ...
1
vote
0answers
41 views

Vector points from csv file wrong location in QGIS

I am using QGIS 1.8 (I know old version), and uploaded a csv file with coordinates. The underlying basemap is from Google, using the Open layers plugin. This basemap uses WGS84-epsg3857, and my vector ...
1
vote
1answer
35 views

QGIS installation from OSGeoW4: entry point not found in qgis_core.dll

I have installed QGIS through OSGeo4W installation. My operation system is windows 7 64x. I try to start the program QGIS Desktop from start menu this error: Do I need to do something? Installation ...
0
votes
1answer
36 views

QGIS 2.4 mapRenderer.extent() does not equal mapRenderer.setExtent()

Could anyone help explain this QGIS 2.4 python console code? I would expect the return value of .extent() to be the same as the bounding box given to .setExtent(): mapRenderer = ...
2
votes
2answers
71 views

Saving selection as new shapefile using QGIS gives OGR error?

I have an issue saving a set of polygons as a new layer that I've selected using the polygon select tool in QGIS. After selecting the polygons in the main (source) layer, I've tried two ways: I ...
2
votes
1answer
51 views

Loading features attributes into numpy array

I am currently working on an add-on that relies on the user choosing fields of tables (that can be from shapefiles, csv or dbf) that are open in QGIS and then making computations with such data. ...
0
votes
0answers
77 views

Combine two grids with a small area of overlapping pixels to a new raster in QGIS/SAGA

Hint: the first grid is 1 byte and the second is 2 byte The new raster should have a blended transition. How can i do this?
1
vote
1answer
48 views

How to simplify a multiline geometry in QGIS?

I'm trying to simplify my shapefile, which uses a lot of vertices to represent curvatures, by using the Generalizer plugin. But no matter what threshold I use for Douglas algorithm, it still includes ...
0
votes
0answers
18 views

How can one use Google Maps API to mimic QGIS projection/CRS

I used QGIS to find the extents of a list of features. However, the resulting data auto-generates the CRS and changes it from WSG84 to a custom one. Is there a way to use the autogenerated CRS in ...
1
vote
1answer
34 views

Why do I get an error message at QGIS training manual 3.3?

I have a problem following the QGIS training manual lesson 3.3 (Ratio Classification). You have to add a column to an SQlite layer. The new column is AREA. I followed the instructions and added it as ...
1
vote
1answer
19 views

Difference between source SRS and target SRS in Raster Warp function

Hello I am trying to change a raster layer projections from WGS84 to a custom Lambert layer using 'Raster' --> 'Projections' --> 'Warp' function. I have been asked for source SRS and get SRS. what is ...
1
vote
0answers
36 views

Extracting raster values with polylines in QGIS

I have a polyline shapefile that represent a road an a raster grid with slope values. Is it possible to interpolate the shape file and the grid to have the average slope of the road? I know that I can ...
0
votes
1answer
44 views

CRS of QGIS bounding boxes

I used QGIS to find the extents/bounding boxes of a list of features from census data. I used the following method: Vector - Research tools - Polygon From Layer Extent, which creates a new shapefile ...
0
votes
1answer
34 views

cannot split a line using QgsGeometry.splitGeometry in QGIS

I create a new qgis file and run the following code. # create a line line = QgsFeature() line.setGeometry(QgsGeometry.fromPolyline([QgsPoint(50,50), QgsPoint(10,10)])) # create a layer layer = ...
0
votes
1answer
64 views

Determining unknown Coordinate System using QGIS?

I'm trying to figure out the coordinate system of some data I downloaded from a no-longer-maintained USDA website. The data's still accurate, it's just floating in space. I've tried several ...
0
votes
0answers
43 views

What happened with NVIZ?

I'm unable to find and run NVIZ and now I've read several places that it's not functioning in the latest versions of QGIS? Is this a temporarily bug or definite?
3
votes
0answers
41 views

Resampling air temperature gridded data to sub-grid resolution

I'd like to obtain a 30-m resolution gridded dataset of air temperature from the ~1km gridded data of WorldClim, of Hijmans et al., 2005) for a mountainous region. The easiest procedure (I thought ...
2
votes
0answers
60 views

How can I store height info from GPS in QGIS?

I want to use QGIS as a tool for collecting GPS-Data in the field. One use case would be simple surevy tasks where I want to store the three dimensional position of points. QGIS is working fine on the ...
0
votes
0answers
41 views

How to manage two map items in a QGIS composition with python?

I need to manage two different map items in the same map composition, with a stand alone python script. Each composer map has been referenced like this: composerMap1 = ...