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

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8
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253 views

Connecting Problem: ODBC versus ESRI Personal Geodatabase (*.mdb)

I try over 2 days to connect an ESRI Personal Geodatabase with QGIS 2.8.1 Here is my testing report. Testing environment: Windows 7 64-bit; MS Office 32-bit; QGIS 32-Bit 1. Step: Creating an ...
7
votes
0answers
171 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(), ...
7
votes
0answers
101 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
636 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 ...
7
votes
0answers
610 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
676 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
63 views

Project an attribute from one polygon layer to another

I have 2 polygon layers which can be found here. The two layers are overlapping. The first contains a map of the German counties in 1928 and the second the counties how they are in 2014. The 2014 ...
6
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0answers
58 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 ...
6
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84 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 ...
6
votes
0answers
214 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 ...
6
votes
0answers
701 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 ...
6
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477 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
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0answers
772 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
405 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 take a long time, but doesn't terminate, what might be the problem? 17 Oct 12:33:25 INFO ...
6
votes
0answers
510 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 ...
5
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0answers
74 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. ...
5
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0answers
52 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 ...
5
votes
0answers
99 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
73 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 plugin ...
5
votes
0answers
107 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 ...
5
votes
0answers
257 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 ...
5
votes
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68 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
77 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
93 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
149 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
271 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 ...
5
votes
0answers
130 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
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0answers
279 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
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0answers
154 views

Distribute QGis plugin which depends on certain Python packages

I developed a plugin for Qgis which depends on some Python packages. On Linux and Mac, this is not really a problem because I can easily install them with the system pip command. Windows is another ...
5
votes
0answers
438 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
462 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 ...
5
votes
0answers
254 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
236 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
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 ...
4
votes
0answers
50 views

Calculating angle using three WGS 84 points

I am looking for a way to calculate an angle between two points at a specific third point. My coordinate system is WGS 84. I can measure the angle with QGIS clicken on those three points, but I want ...
4
votes
0answers
26 views

QGIS Atlas: Filter maps based on attributes (more than one)?

I have a series of maps with the same geographic boundaries but with different set of points (from the same layer). I would like to create an Atlas where the change is based on the attributes. A ...
4
votes
0answers
36 views

Can I clip a geodatabase vector layer in QGIS?

I have a Vector layer loaded from a .gdb (geodatabase directory). I'm seeing my contour lines fine. I've drawn a polygon on top of the area I want to crop on a new layer. I select Geoprocessing ...
4
votes
0answers
41 views

Different styles in same label

I have a multiline label made of 3 attributes made through an expression like: "Length" || '/' || "Level" || '/' || '→ ' || "Bearing" || ' ←' I'd like to make the Length and Level lines in ...
4
votes
0answers
51 views

QGIS Profile Tool shows no profile

I have installed and followed the process to produce an elevation profile from the Route Profile plug-in in QGIS, but for some reason I am getting no profile to appear. The grids are from OS ...
4
votes
0answers
35 views

Custom forms feature in QGIS: QMessageBox.warning closes QDialog as well

I am attempting to work with custom forms in QGIS. I have included a validate function in my code that will pop a QMessageBox() if the validation fails. My problem is that when I close the QMessageBox ...
4
votes
0answers
43 views

OS terrain 50: .vrt from zip files

I tried to follow what was suggested in How to use OS Terrain 50 in QGIS, but I got the following problem: in spite of being generally able to generate .vrt files using gdalbuildvrt from unzipped ...
4
votes
0answers
25 views

Stretch to MinMax results in blank render output in QGIS?

I am a new QGIS user, and I can't figure out if I encountered a bug. If I have a multi-layer image, and "Multiband color" -> "Stretch to MinMax" selected I get the following behaviour. QGIS takes a ...
4
votes
0answers
49 views

QGIS 2.10 Can't load georeference plugin?

Apparently my problem was already present in older versions of Qgis. I don't know how to fix it, knowing I have a Linux system (Fedora 23). Somethiing similar here : Where to download QGIS 2.10? So, ...
4
votes
0answers
40 views

Buffer neighbouring polygons without overlap using QGIS

Is it possible to create a buffer around neighbouring polygons, so that the new polygons do not overlap? Preferably in QGIS but any other tool will do. So instead of the first result I would like ...
4
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0answers
40 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?
4
votes
0answers
25 views

Center my contour values in QGIS

In QGIS have an issue with my contour value labels being pushed to the edge of my map, instead of lining up at the center where they seem to have more space. Does anyone know why this happens for some ...
4
votes
0answers
36 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, ...
4
votes
0answers
26 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 ...
4
votes
0answers
27 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 ...
4
votes
0answers
59 views

How to load layers from postgres using SELECT statement?

I am trying to load a postgres table (columns extracted using a select statement) from the python console in QGis: The following works fine and the layer loads as expected: uri = QgsDataSourceURI() ...