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

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1answer
95 views

Is it possible to create tiles with transparent background using Qtiles?

I had created the tiles from shapefile using qtiles plugin in QGIS and that shapefile layer is a label layer created using MMQGIS plugin. But the thing is I want that tiles with transparent ...
1
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1answer
48 views

Open and split a 4 channel RGB picture

How can I split an 4 channel rgb pic in qgis? With the value tool I can see 4 channel. I tried to use the RGB to PCT tool but I always get an error (File "C:\PROGRA~1\QGISBR~1\bin\pct2rgb.py", line ...
1
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1answer
75 views

How to compute tabulate intersection in QGIS?

I have a base layer of census data in census tracts (polygons). I'm looking to intersect those tracts with a buffer layer but I only want to include those census tracts whose area is over 50% within ...
1
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2answers
108 views

Merging shapefile layers not working in QGIS?

How do i merge different vector layers in to one shapefile layer In QGIS version 2.6
1
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1answer
35 views

If statement using QgsRasterCalculator

So in the sequence of my previous question (Can't use Raster Calculator with two different rasters), I am stuck again in my project. With my source rasters, I created 3 different outputs using ...
2
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0answers
45 views

QGIS raster data from vector and raster files

Excuse me if my GIS terminology is a bit shaky, and for the length of the post, as I am a complete beginner to GIS and this is my first forum post. I am using QGIS 2.6 32bit on Windows 7. 1 My data ...
2
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0answers
45 views

QgsRubberBand with holes

I tried to create a QgsRubberBand object with holes, but failed: rb = QgsRubberBand(iface.mapCanvas(),True) geom = QgsGeometry.fromWkt("POLYGON((0 0,4 0,4 3,0 3,0 0),(1 1,3 1,3 2,1 2,1 1))") ...
5
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3answers
188 views

Alternative to OpenLayers plugin for QGIS?

Are there any alternatives to OpenLayers plugin to have Google / Bing maps for QGIS projects? I need an high quality cartography (both aerial and street view) but OpenLayer plugin do not allow to ...
1
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1answer
60 views

How to make rectangle selection on QgsMapCanvas?

I have this code for create and open raster map: if(QFile::exists(rasterFileName)) { QFileInfo myRasterFileInfo(rasterFileName); m_pRasterLayer = QSharedPointer<QgsRasterLayer>( ...
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0answers
47 views

Transparency on black/white raster after clipping in QGIS?

I'm new to this forum and QGIS. I'ld really appreciate it if you could help me with my problem, since I couldn't find any solution online but people experiencing the same issue. It seems as if this ...
2
votes
1answer
112 views

Soils sampling. How to make polygons from interpolated points?

My goal is to make a shape file with polygons for variable rate fertilizer application within a farm field. I have a point shape file with soil sample values (pH, P, K and so on) and a line/polygon ...
2
votes
1answer
86 views

Use 2 different symbologies on the same feature QGIS

I have data symbolized with different categories Each category has a field for different symbology style like the table below. Is it possible to visualize the same category of data with in ...
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2answers
114 views

How to add 2 layers in qgis and display them at the same time

I added 2 layers in qgis using python but only one layer is shown on canvas. After clicking (anywhere on the canvas) both layers are displayed. layer = ...
-1
votes
1answer
39 views

How to decrease elevation values of DEM using open source GIS sotware? [closed]

I am newbie in QGIS, but I was wondering how to decrease elevation dem DEM using QGIS? Can QGIS do that? Or anyone of you can tell me any open source GIS software to perform that?
3
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0answers
256 views

Connect to QGIS 2.6 Python Plugin function via button on custom feature form

I am trying to connect to a QGIS 2.6 Python plugin function via a custom feature form button. On my feature form, I'm attempting to do a few things : enable the updateButton only if the ...
1
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1answer
48 views

QGIS 2.6 : Programmatically setting key value pairs for ValueMap widget

Using QGIS 2.6 and Python 2.7 on Windows 7, I am trying to programmatically insert key value pairs into a ValueMap widget via a csv file. Issue is that some of the values are properly inserted and ...
2
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1answer
43 views

Label interior of polygon boundary

I'm using QGIS 2.6.1 and would like to label US state polygons such that each border is lined with the label of its two states. Something like this: It appears that the current labeling engine ...
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0answers
86 views

Reprojecting a population raster from LAEA to lonlat

I have a population density raster from the EEA which is based on the CORINE land cover 2000 data. ...
2
votes
1answer
36 views

QGIS Change treeview categories in browser(2) panel

The main categories of the treeview in the browser panel seem to be hard coded. Is it possible to 1.) add, delete or rename categories (e.g. instead of "Project home" name it "Data") 2.) link ...
1
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0answers
63 views

QGIS and GRASS r.fill.dir processing times

I am new to the open source software and have performed analysis in ArcGIS in the past. I am learning as I go on this processes for OS. I am trying to calculate stream order (strahler) on a 1 gig ...
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0answers
34 views

Use QGIS as API [closed]

I would like to develop a simple application to use raster and map from a server. Is it possible to use QGIS as API to display map and raster? I also know that QGIS use API and library like ...
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0answers
53 views

QGIS polygon - filling a polygon gap

I do not use Python, I'm afraid. I need to fill in a polygon gap for this map of Scotland. Here is the gap: How do I fill in this gap? I have already tried drawing another polygon inside the gap ...
2
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1answer
39 views

How to display variable number of images associated with one point on QGIS

I have a set of point locations. I have a set of images with reference numbers. I'd like a way to easily see the images associated with the location, using QGIS. This is for my own use rather than ...
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0answers
47 views

QGIS Processing modeller fails when running field calculator

I have a problem running a model that I use to create columns with the coordinates for the start and end points of a line. This model used to work but now the model gives me this error :Algorithm ...
1
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1answer
48 views

Is it possible to print one item legend item in italic in print composer?

Is it possible to have one item in italic font (species names) and the rest in "normal"? I use QGIS 2.6. The legend consists of two items which should be written normal (trap positions and ...
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1answer
139 views

Load the raster image which is in TIF format using QGIS API

I am quite new inthe field of GIS. I am interested in is to load the raster image which is in TIF format using QGIS API I have followed the steps given the in the follwing link to load shape file ...
2
votes
1answer
104 views

How to select features using an expression with pyqgis?

How can I select features with pyqgis using an expression? I tried to use an QgsExpression but the select method doesn't take it: exp = QgsExpression("'ogc_fid' = 482") cLayer = ...
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1answer
247 views

QGIS 2.6.1 Brighton/ Grass pluggin r.stream.xxxx

I just updated my OSGeo4W and now have QGIS 2.6.1 and GRASS 6.4.4 and am trying to get strahler stream order. I am figuring out GRASS 6.4.4 GUI by itself but GRASS is easier withing QGIS, however, I ...
0
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0answers
23 views

QGis crash when open georeferencer generated image

I'm trying to georeference an image with the georeferencer, QGis creates the geotiff, I can open in other image viewers but when I try to open in QGis it crashes. A friend tested in arcgis and it ...
1
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2answers
57 views

Free solution for an intranet geodatabase for point data, connectable to QGIS / MapInfo

I have a plenty of point measurements - thousands of points with date/time, gps, measured values etc. I would like to make it possible to put all my particular datasets (can decide whether shp or ...
1
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0answers
90 views

Update WFS Layer with QGIS - Commit errors

In QGis: Importing WFS Layer from Server, changing Attributes, trying to save. I get Commit errors: Could not commit changes to layer ah_neu:mylayer. The geoservers logfile says: 2015-01-21 ...
2
votes
1answer
61 views

QGIS 2.4 graphical modeler add field: error executing algorithm

I have to add more than 20 fields to a lot of shapefiles. I used to do it with the tablemanager plugin. Beside it is time consuming, misstakes can be made. So I want to automate that procedure ...
3
votes
1answer
341 views

How to create a missing dbf file for shapefile?

I have a shape file (shp) which is missing its dbf. I tried to load this into Postgis using shp2pgsql and got the could not open shapename.dbf error. I opened it in QGIS, without issue, and ...
2
votes
1answer
92 views

How to zoom to selected feature with QGIS Python Console

I want to select a feature by ID and zoom to it. I tried the following but the canvas doesn't change. Any ideas? canvas = qgis.utils.iface.mapCanvas() cLayer = canvas.currentLayer() cLayer.select(51) ...
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0answers
27 views

How to get background maps to show in QGIS Cloud mobile version?

we're a group in Denmark, trying to publish some maps for use on a mobile device, but although our background maps show up in the desktop version, we can't get the mobile version to show them - What ...
2
votes
1answer
115 views

Export several files at the same time in QGIS

I have a lot of .TAB files open in QGIS and I want to save them to .SHP so I can work with them in ArcMap. Is there a way to save/export all these files at the same time or do I really have to "save ...
1
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1answer
87 views

Couldn't load plugin PRISM due an error when calling its classFactory() method in QGIS1.8 inWin8

When I load a plugin in QGIS ,met some problems : I had tried copy other Python27's files to QGIS's Python 27 file but it still does't work. Couldn't load plugin PRISM due an error when calling ...
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0answers
74 views

Create polygons enclosing same number of points on PostGIS

I have a geodatabase on Postgis with points representing customers, what i need is give a number of customers, lets say 100 and it need to generate polygons enclosing 100 clients each one. I only ...
7
votes
1answer
215 views

Why the order of imports matters in a standalone PyQGIS processing script?

I've come across a weird issue while running standalone PyQGIS processing scripts. The order of imports in the script affects its normal execution. You can reproduce the problem by opening a Python ...
2
votes
1answer
63 views

QGIS Interpolation on Curved Grid (River DEMs)

Hi QGIS experts out there, I have an very hard task I want to do in QGIS (or another open source GIS program). I have point data for river bathymetry (depth). I have been creating digital elevation ...
2
votes
0answers
45 views

Is there a QGIS alternative for ArcMap's Append (to Shapefile) Data management tool?

Is there something out there for QGIS that is similar to the Append Tool in ArcMap? Reason I am looking: I am currently working on a storm drainage project that involves GPSing Storm drain lids. My ...
2
votes
1answer
122 views

GRASS plugin absent from QGIS 2.6 OSGeo4W install

I've just installed QGIS 2.6 Brighton using the OSGeo4W installation. The GRASS toolbox plugin has not, however installed as it had been with previous versions. Before, I was able to access the GRASS ...
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0answers
18 views

gdal_polygonize floating values [duplicate]

gdal_polygonize converts whatever rasters values into vector integers as it is based on the GDALPolygonize() function (http://gdal.org/gdal__alg_8h.html#a3f522a9035d3512b5d414fb4752671b1). It is ...
4
votes
1answer
116 views

How can I open a GDB on QGIS for Mac?

I'm trying to open a GDB on QGIS for Mac but having no luck. Details: I'm currently running OS 10.9.3 on my laptop. I downloaded and installed QGIS 2.6.1-2 from KyngChaos I installed the GDAL ...
1
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1answer
123 views

Loading Oracle Spatial Layers in standalone python qgis

I used below script to connect to postgres and load layers successfully.I want to aceive this using Oracle Spatial for both vector and raster loading.How can I achieve that?In other words what is the ...
3
votes
1answer
158 views

How do you add North Arrow which adjusts to the map rotation in QGIS?

How do you add a working North Arrow into QGIS. One that will rotate if the map is rotated? I'm aware that in QGIS the North Arrow icon is just an image (Layout->Add Image/Arrow), what I need to know ...
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0answers
44 views

get the ogr_SDE.dll from the MapServer

can please some one give help to get the ogr_SDE.dll from http://www.maptools.org/ms4w/index.phtml?page=home.html I will connect the ArcSDE to my QGis, like that intruction ...
4
votes
6answers
296 views

How do I make a SHP file from waypoints?

I have a Garmin etrex 20 and I want to convert my waypoints into a shapefile for QGIS. The waypoints need their name and background information with them in the shapefile.
1
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2answers
52 views

How can I disable logs being created in standalone python script?

When I run the following script in QGIS 2.6.1, it produces a folder called 'processing', which contains a log, in the directory it reads files from. And since the script reads files from several ...
2
votes
1answer
174 views

Where is the OSGeo4W setup for QGIS 2.6.1?

The downloads site for QGIS appears to only contain standalone installers. I want to install QGIS 2.6.1 using the OSGeo4W Network Installer (64 bit). When I do this currently, I install QGIS 2.7 which ...