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

learn more… | top users | synonyms

18
votes
0answers
186 views

Output formats for QGIS Heatmap plugin not appearing in drop-drown in Ubuntu

I've been trying to use the heatmap plugin on QGIS (2.8.2) on Ubuntu(14.04) but the drop down for the output formats doesn't get populated. Selecting the drop-down allows me to press OK on the ...
10
votes
0answers
226 views

PyQGIS save raster as rendered image, then use GDAL tools on it

I have tried to use the code from QGis Save Raster as Rendered Image. i is a raster layer: pipelayer = i pipeextent = pipelayer.extent() pipewidth, pipeheight = (pipelayer.width(), ...
10
votes
0answers
750 views

Modifying File GDB Feature Class Features Using QGIS

I've installed the File GDB API using the OSGEO4W advanced installation when installing QGIS. I've had a bit of trouble with it initially and have posted a few questions with some helpful Stack ...
10
votes
0answers
580 views

How to reverse-georeference with QGIS?

I have a map with a "strange" projection (it's basically hand-painted, not an exact one). I can easily georeference it in QGIS using the Georeferencer plugin and the Thin Plate Spline transformation ...
8
votes
0answers
154 views

How to display charts next to features in the map?

This question is meant to be primarily on QGIS software but all other software solutions are welcome as far as it is possible to achieve it as easy as possible, preferably out of the box. Though the ...
8
votes
0answers
134 views

How to access a deleted features attributes (before committing)

I have a signal setup for a feature deletion event on a layer: self.layer.featureDeleted.connect(self.feature_deleted) When I try and grab an attribute from the deleted feature on the slot, a ...
7
votes
0answers
106 views

Duplicate layer using Control button on keyboard

I noticed in QGIS 2.14 I can hold Ctrl key and drag to duplicate a layer. But this seems to create a copy linked from source layer. Unlike if I use "Duplicate" in context menu this procedure reflects ...
7
votes
0answers
81 views

Perform QGIS modeler multiple raster calculations with data from external CSV

I need to perform multiple calculations on a set of rasters based on values in a CSV metadata file. I'm using the QGIS graphical modeler and can call a specific field in a CSV with the Table and ...
7
votes
0answers
74 views

QGIS: large .vrt indexing

I have a large number of small tiles merged into a single VRT. The rasters are only viewed at large scale, so only a few of them are visible at the same time. The map refresh in qgis is slowing down ...
7
votes
0answers
242 views

Frontal Detection of sst & Chlorophyll image

I am working on sea surface temperature satellite images and looking for delineating gradients in open source on the basis of temperature. Is there any tool like Cayula and Cornillon front detection ...
7
votes
0answers
868 views

Link QGIS to Anaconda Python Distribution: Spyder, iPython Notebook, pip, scikit-learn

I have Anaconda as my primary Python distro, and want to route Python related QGIS scripts through it. With Anaconda, I have Spyder, can easily install packages with pip, and can launch a iPython ...
7
votes
0answers
667 views

Grouping analysis of points to divide polygon into n number of sub-regions using QGIS?

I'm attempting to create n sub-regions from a polygon based on a cluster analysis of a bunch of overlapping raster layers (physical layers, eg: depth, currents, waves). Briefly, I can create a ...
7
votes
0answers
425 views

What to do about Geoserver WPS warning“ ”Could not get a ServiceInfo"?

This is the warning I am getting when I try to use this WPS service from QGIS, and the processing time is taking too long, but doesn't terminate. What might be the problem? 17 Oct 12:33:25 INFO ...
7
votes
0answers
685 views

How to get rpy2 for QGIS on OSX?

I am a new QGIS user, have installed QGIS on a Mac running Snow Leopard OSX 10.6.8 following all the instructions. QGIS seems to work well for everything other than when I boot up I get the message ...
6
votes
0answers
93 views

Can a memory layer be used as an input and/or output with runalg?

Can a memory layer be used as an input and/or output with runalg? With runandload I get this to work: processing.runandload("qgis:mergevectorlayers","memory:bufferOne", "memory:bufferTwo", ...
6
votes
0answers
84 views

Exotic Projections QGIS

I would like to use some projections in QGIS that I can't see supported directly. An example would be something like this conformal cube projection. ...
6
votes
0answers
64 views

Styling polyline to view which part is above another in self intersection using QGIS?

I need to view a polyline constructed from waypoints of a gps track, that has self intersections in curves, like an exit loop from a highway. I need to visualize it in a way that allow to know which ...
6
votes
0answers
128 views

Create buffer based on polyline without line end caps and without dissolving the created polygons in QGis

I have a projected line layer (Shapefile) in QGIS. For every line segment I want to create a polygon without line end caps. The resulting polygone should not be dissolved to a single one. I tried ...
6
votes
0answers
305 views

Why is QGIS georeferencer much faster on Windows than Mac?

I just went from temporarily using a Windows 7 machine with 4GB of RAM and no video card as far as I know. I'm now using a mac with 16GB of ram, etc. Its a much more powerful machine. However, QGis's ...
6
votes
0answers
320 views

Performing buffering and intersection with script in PyQGIS

I wrote a script that performs the intersection of two layers: The first Layer -> layer1, represents the rivers The second Layer -> layer2, represents a set of circular dots distributed in a ...
6
votes
0answers
536 views

Printing/exporting WMTS tile layer with desired resolution / zoom level in QGIS

I have a project which uses WMTS and some vector layers in QGIS. I can freely zoom in and out, and tiles are refreshed with appropriate zoom level, just as expected. Now I would like to export part ...
6
votes
0answers
851 views

How to use the linear referencing plugin from QGIS with postGIS data?

I need a guide how to use this plugin properly, I'm a newbie on PostGIS and I'm trying to use the linear referencing plugin of QGIS. I've created a database on postgreSQL with the postGIS extension ...
6
votes
0answers
487 views

How do I install Orfeo toolbox and Qgis 1.9?

I'm having a lot of trouble getting Orfeo toolbox and Qgis 2.0 working. I followed the qgis wiki instructios, added the ppa, installed qgis 1.9 (it's beautiful, great work!). But when i tried to ...
6
votes
0answers
1k views

How to create point labels from midpoints of road polylines in QGIS?

Heres what i want to achieve: i have a roading polyline layer (singlepart ie has several features per road, grouped by an id field), and i want to (after merging the parts) find the mid point of the ...
5
votes
0answers
28 views

Automatically style raster using unique values in QGIS?

In ArcMap, it is possible to automatically calculate the unique values for a raster and then apply a different style to each unique value (see 1st image). However, in QGIS, I have to manually add ...
5
votes
0answers
51 views

See python script running while processing a task in QGIS?

Is it possible to see scripts running in Python Console - everything from tools and analysis vector to raster?
5
votes
0answers
53 views

SAGA-Inverse Distance Weighting in QGIS - How to Set Minimum Number of Points?

I am analyzing a postGIS point dataset in QGIS version 2.8.2, about 200k features total. To calculate weighted average values I am using the Inverse Distance Weighted interpolation technique. However, ...
5
votes
0answers
39 views

QGIS becomes non-responsive when adding jpg raster layer

When trying to add a raster layer (georeferenced jpg-files) QGIS becomes non-responsive. I have tested the jpgs and they are not corrupted, sometimes they appear and it works for a little while before ...
5
votes
0answers
134 views

How to speed up simultaneous working with PostGIS layers in QGIS?

we are working on one big layer at the same time (10-20 people). Some of us use QGIS 2.8.1 and the other 2.6. The user with 2.8 have a lot of crashes (QGIS). The 2.6 users don't have this crashes but ...
5
votes
0answers
74 views

QGIS Cross Section Profile Distance using Ellipsoid?

I am working with QGIS 1.8 and 2.6 and can't get any of the Cross Section Profile tools to provide the ellipsoid ("proper") distances. All the distances use geographic coordinates which are too ...
5
votes
0answers
84 views

Generate a series of ellipses on a line

I am trying to create a series of ellipses (mocked up in green below) of defined dimensions along a line. I have got as far as generating regularly spaced points along the line that are attributed ...
5
votes
0answers
109 views

What Does the Cell Value in a Composite Raster Mean?

When I make a composite raster in QGIS using the GRASS r.composite tool and then click on a certain cell I get these values in the blue/green/red/composite rasters: blue = 124 green = 124 red = 172 ...
5
votes
0answers
98 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 ...
5
votes
0answers
197 views

Is there a limitation on the numbers of layers that can be displayed in QGIS?

I have been looking for an answer to this question for the last several weeks, so hope that someone here has encountered the same issue and has a viable solution to my problem. I am currently using ...
5
votes
0answers
152 views

Is there a limit to the number of polygon points you can export to CSV in QGIS 2.4?

Using QGIS 2.4 I am currently importing a csv file with ~30,000 polygons (polygons in WKT format). I also have a United States shapefile. I have used the Clip function to get only the polygons that ...
5
votes
0answers
310 views

QGIS: How to reverse vertex ordering in polygons

I am working with an Oracle spatial connection in QGIS through which I am accessing and editing a vector layer. I find that when I edit a geometry, the vertex ordering is reversed (to clockwise in the ...
5
votes
0answers
478 views

Weather conditions forecasting / interpolation

I'm trying to carry out weather conditions interpolations. I have information of 92 weather stations for 800,000 km2. As you can imagine the extension of land is huge and I need some kind or weather ...
5
votes
0answers
268 views

QGIS does not read ESRI Geodatabase correctly

I have a geodatabase from the EPA that does not seem to me reading correctly with Quantum GIS. QGIS Version 1.8.0 (Lisboa) and GDAL/OGR 1.9.2 When I open the attribute table the first two columns ...
5
votes
0answers
254 views

How to write an address search plugin?

I am migrating some users from MapInfo to QGIS, and before they sign off on it, they want a very simple address search in the same way that we currently have one working in MapBasic. I;ve been having ...
5
votes
0answers
137 views

Why doesn't Polygonizer copy the line ids to my polygonized shapefile?

I am trying to convert a line shapefile into a polygon shapefile using Polygonizer plugin, and when my new polygons are created all the cells in my id field are "Null", although I have clicked "copy ...
4
votes
0answers
26 views

QGIS Renders Buffer Polygons from ArcGIS Feature Class Differently

I have a polygon feature class stored in an ArcGIS geodatabase. All of the shapes are buffers of a point layer created using the editor menu's 'Buffer' command. In ArcMap 10.3.1 the data looks like ...
4
votes
0answers
23 views

How can I get a numerical (or value) display for equal intervals in a layer?

I'm looking to classify regions on a map by the amount of light pollution in the area. I have the varied intensities (0 through 60) plotted using a color map, but is there anyway that instead of a ...
4
votes
0answers
49 views

Issues updating field values programmatically for particular field data type on 64bit Windows computer using QGIS 2.8.7

I have an issue with a plugin for QGIS 2.8 I'm developing when using it on a Windows 64bit machine (as opposed to 32bit). I am trying to update values in a particular field in my plugin, and the ...
4
votes
0answers
61 views

Import Vector data to QGIS from pdf and apply georeference

I am Using QGIS 2.14. I have a pdf created by Mapinfo, it contains multiple layers of vector data that I can open as separate vector layers in qgis. However no map projection data was saved to the ...
4
votes
0answers
73 views

Which statistical methods to compare the spatial distribution of two different variables in two raster maps?

I am working with two global raster maps using the R Software (original file: netCDF for map 1 and GeoTIFF for map 2), with a resolution of 5 min of arc. Map 1 contains data on the share of the land ...
4
votes
0answers
41 views

QGIS canvas: I cannot remove blue “nested” grid/rectangles in canvas (BTW what is it?)

A blue "nested" grid suddenly appeared in the canvas (see image below). I don't know what I did to make this happen and how to get rid of it. Can anyone please advise me on how to remove this?
4
votes
0answers
46 views

TypeError: QgsEncodingFileDialog

I am using the latest version of QGIS (Lyon) on MAC and have set the default Python version 2.7. Moreover, I have installed all the required python modules and GDAL. It was working before, but now, ...
4
votes
0answers
36 views

Is it possible to have a locked TOC in QGIS

I would like to customize QGIS for a custom use case where the user will work with a very simple customized UI and will just digitize features in existing layers. Therefore the TOC should be locked, ...
4
votes
0answers
54 views

Insert sequential row and column values automatically into a fishnet dataset

I have a grid that has about 30 rows with approx 15 columns each. I want to label them as A1,A2,B1,B2 etc (Alphabet row, integer is column). Is there any way to do this programatically? There is no ...
4
votes
0answers
83 views

QGIS/OGR shp to tab export - crashing Mapinfo due to number format issues

I created a vector grid in QGIS and it exports as SHP -no issues. When I save as tab and try to open the file in MapInfo it crashes. According to ...