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

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11 views

How can you create a depth raster from a DTM and a polygon in QGIS?

I have a DTM raster and a flood outline in polygon format - how do I create a depth raster for the flood outline (i.e. flood level minus DTM level)?
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0answers
10 views

How to reference a number variable in r.mapcalc within QGIS graphical modeler

I need to run the following formula in r.mapcalc: (xor(abs(A-B),abs(A-C))>120)*A I would like to however use a user defined number input variable instead of the 120. I already have this variable ...
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0answers
9 views

In QGIS, is it possible to save graduated styles to use on different columns?

I'm using QGIS to produce thematic maps of 9 quantities (given in 9 columns in the attribute table) which have values broadly within the same range and I would like to plot them using the same ...
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2answers
20 views

kml does not overlay correctly in QGIS

In QGIS, when I insert a kml contour that was created in Google Earth, it appears misaligned in respect to all the other layers. Note in this image how the red contour is moved upwards with respect ...
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0answers
15 views

insert row into postgis query table in QGIS

I find I am using QGIS (2.4) more and more as a client for PostGIS database tables with geometry, but also for tables without geometry, partly because it's good just to use the one application and ...
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0answers
15 views

Is there an editing function in qgis cloud? [on hold]

does someone know if an editing function exists in qgis cloud? or maybe is planned?
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0answers
37 views

Double labels in QGIS

I want to create labels like a fraction using data from two columns. I have tried to use: "Field" || '\n' || '――' || '\n' || "Field2" but it doesn't look good. How can I do it using other method? ...
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0answers
23 views

Creating Form in QGIS

I want to create a form for editing attributes in QGIS. I have a lot of question and hope somebody can suggest how they work or where I can read about the next elements of form: Classification List ...
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0answers
11 views

How to create a svg item onto Map Canvas in QGIS API?

I'm working on a project with QGIS-2.4.0 API using C++. I need to load some svg files to the application for displaying as symbols. QGIS API has a class named QgsMapCanvasItem, which is an abstract ...
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1answer
38 views

Setting up QGIS Server at low cost for small user community?

I want to setup QGIS Server at a low cost for a small user community (mainly me). Parameters: Some data is private so something like qgis cloud not an option (not enough money for paid option). ...
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1answer
37 views

How to use bold text in QGIS font marker symbol?

Is it possible to use bold text with the Font marker symbol in a QGIS (point) layer?
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2answers
48 views

How to style graduated using size-scale field

Is it possible to style based on size-scale field using graduated symbol but instead of using color ramp, I would like to display its size. I would also like to display this in the legend in the map ...
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0answers
38 views

Dark Object Subtraction QGIS

I'm trying to do Dark Object Subtraction (DOS) for a Spot2 and 4. I have calculated the TOA reflectance and now want to get the at surface reflectance. Using QGIS I would like to know how I can do ...
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1answer
31 views

What's the reason for this Invalid Layer “Cannot open GDAL dataset …” error

When adding a rasterfile with QGIS python console there appears an error when the first letter of a rasterfile to be added is not written in capital letters. Why this behaviour? Example case1: ...
2
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1answer
27 views

How to store a password during one QGIS work session?

I'd like to get into qgis-plugin development, but am rather new to both python and QGIS development. I intend to write a plugin which connects data from a mysql database to shapefiles. As the data is ...
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0answers
30 views

How to combine Polygons and points? [on hold]

Sorry for the basic question. I'm using qgis. I have two layers, one with points (a file that contains addresses with latitudes and longitudes linked to several variables), and another layer (a ...
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2answers
35 views

QGIS doesn't create the correct projections when creating new shp files

I received shapefiles exported from ArcGIS with EPSG:2227 as the CRS, which should be: +proj=lcc +lat_1=38.43333333333333 +lat_2=37.06666666666667 +lat_0=36.5 +lon_0=-120.5 +x_0=2000000.0001016 ...
4
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0answers
36 views

How do ESRI and QGIS calculate scale values of geographic projections?

Does anyone know how (from which location) scale values are calculated in ESRI products and QGIS for geographic projections? The only thing I've noticed is that QGIS is changing scales when you pan ...
3
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2answers
179 views

How to calculate the square root of a feature attribute?

I have a polygon shapefile with over 16k features. Each has an attribute (Double, Precision(10) Scale (2)) that I am trying to calculate the square root of, and store in new field. Is there a tool, ...
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0answers
14 views

Can HTML annotations be autogenerated for each location in QGIS 2.4

Can HTML Annotation Boxes be autogenerated on the whole map, linked to locations, and always have the same html file loaded for all of them?
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2answers
58 views

Creating counties in QGIS

I have a raster map (a photocopy I took from an Atlas), and a vector map of the UK. The raster map shows pre-1890 Scottish county borders. I have geocoded the map so that the raster borders overlap ...
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1answer
28 views

Reprojected Shapefile does not align with Openlayers Plugin

I am based in NSW, Australia. I have a shapefile that when I underlay with the openlayer plugin (google satellite), the shapefile is skewed despite all my efforts to correct it. I changed the ...
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0answers
17 views

unable to open the QGIS Tab

I have download the QGIS Softarwe of “gis-osgeo4w-1.7.3-00624b3” and “QGIS-OSGeo4W-1.8.0-2-Setup” both from net and installed both in my system, My system is running window07 professional Service ...
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0answers
20 views

QGIS Equivalent of MapInfo's 'Combine Objects using Column' [duplicate]

MapInfo has a function that takes a table, and creates a new table populated combines them by a specified value. So, combining on the name field, and specifying that the Area field should be ...
3
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1answer
296 views

Adding an “m” to the end of every number in a row

What function do i need to use to add an space and an m after every item in a row, using the field calculator in the attributes table. I have a load of numbers (as strings) and would like to add m ...
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0answers
14 views

Splitting existing polygons with existing polylines(roads) with GME tool “split polygon by lines”

After reading through many of these articles i believe the GME tool "split polygon by lines" should be useful to my problem. I have a polygon that needs to be split by a road layer. When i run this ...
3
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2answers
52 views

Converting huge multipolygon to polygons

I have a shapefile with some huge multipolygons, with 100.000's of parts. What would be the easiest way to split them to singlepart polygons? I'm looking for something like QGIS ”Multipart to ...
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0answers
34 views

Why a shapefile of a geological map is not the fault lines are displayed in QGIS?

I am a new user of QGIS 2.4. I do not display correctrly geological SHP layer. This shape contains polygons with shapes, fault lines, dips, volcanic structures, shoreline types, geological boundaries ...
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0answers
6 views

Make the foot of the histogram coincide with the point in QGIS

Is it possible in case of histograms in QGIS to make the foot of the diagram appear above the point or always make them appear above. My issue is that I see the option that maked them appear around ...
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0answers
35 views

Unable to access R from QGIS 2.4

I have been unable to run R from within QGIS on my computer. I have R version 3.03 installed and QGIS 2.4 on Windows 7. R is located at C:\Program Files\R\R-3.0.3\bin\and this is the path e specified ...
2
votes
1answer
33 views

QGIS Intersection problem

The QGIS Intersection tool is not working for two shapefiles in Version 2.2 or 2.4 (haven't tried earlier versions). I get a new shapefile with all the attributes, but no features. However, when I use ...
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0answers
17 views

QGIS WEB Cliente para windows 7

Bom dia, estou com alguma dúvidas a respeito do QGIS WEB Cliente que não consigo achar uma solução. Eu sei que tenho que fazer a instalação do Qgis Serve como esta escrito neste tutorial Anita Graser ...
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0answers
23 views

Is there a way to automate POI collection from websites?

I am searching for an easy method to get lots of points geotagged/georeferenzed into several shape files. I am working at a project where I need to collect all parcel shops in germany (but I will try ...
0
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1answer
22 views

QGIS Python console - save image from bounding box

I want to save an image from QGIS but the save image functionality feels limited. My question is if it's possible to use the python command line to save an image at a specific zoomed in scale and to ...
1
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1answer
23 views

pyQGIS - Data Source is Invalid

Why I am getting Data Source is Invalid in python console of QGIS when running: vlayer = QgsVectorLayer("home/sanjayr/Desktop/india-latest.shp/buildings.shp","sanjay","ogr") I am using QGIS 2.4 on ...
3
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0answers
12 views

Connecting QGIS 2.x to Firebird Database via ODBC?

I tried to connect a Firebird Database in QGIS 2.2 and 2.4 via ODBC to a database and get following error message: Unable to initialize ODBC connection to DSN for SYSDBA/masterkey@Akdees ...
2
votes
1answer
43 views

How to convert unix time to qt time type?

How can I convert unix timestamp to qt time type using qgis field calculator? I would like to avoid importing my table into excel and convert the timestamp to qt time type.
4
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2answers
52 views

The scale in Qgis is not setting to feet

I am working in QGIS 2.4. I have changed the CRS of all the layers and in the project properties to EPSG:102739 - NAD_1983_StatePlane_Texas_Central_FIPS_4203_Feet. I am in print composer trying to ...
3
votes
1answer
26 views

Using QGIS to create a table of correspondence between two area layers

I have two area layers over a map of Australia, and I want to know if it's possible to use QGIS to create a table of correspondences between them. The Australian Bureau of Statistics provides ...
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0answers
38 views

Loading SQLite extensions in QGIS

I have an extension which can be loaded in SQLite using the load_extension function. It would be useful for me if I could load it in QGIS to use in queries made via Database Manager. The Python ...
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0answers
27 views

QGIS using different R lib

I am working with a colleague who is learning QGIS and has a question about the R plugin. His library path (.libPaths()) has two folders: "C:/Users/RDCERWAW/Documents/R/win-library/3.0" "C:/Program ...
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0answers
37 views

Is it possible to export a QGIS project to Mapnik XML?

Is it possible to export a QGIS project to Mapnik xml? I'm using QGIS 2.4 and Quantumnik does not seem to work with that version.
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0answers
30 views

How to compile QGIS 2.4.0 on Ubuntu Precise 12.04

Been trying to compile this for a couple of hours, using this download: http://qgis.org/downloads/qgis-latest.tar.bz2 and these instructions: ...
2
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2answers
54 views

Deleting unconnected lines with QGIS

I am using a road map in shapefile format in order to calculate a route between two points. The map is downloaded from OpenStreetMap and it has small unconnected lines that are messing up my routing. ...
2
votes
1answer
32 views

Data defines symbology in QGIS

I have to make a symbology based on a unique color value so I add a plus column to the attribute table with the number of color values. I went to the layer properties - style - data defined properties ...
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0answers
30 views

QGIS polygon areas inside a polygon

I'm having hard time doing the following analysis in QGIS: I have watershed polygons with individual IDs. Then I have four different shape files, each having different land use polygons. I would ...
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0answers
23 views

How to Interpolate very large datasets in QGIS

I am working with a very large set of point data, (XYAttribute) which I wish to display as a raster. I've been using Interpolate, this is successful but very slow. I have other programmes that simply ...
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0answers
18 views

QGIS plugin for geodesy tasks [closed]

Are there any plugins in QGIS for solution of geodetic problems, construct serif?
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0answers
28 views

Clipping between features within a single vector?

Is it possible (via the Qgis API and friends), to clip polygonal features within a single vector layer? The hope is to accomplish this without having to duplicate the feature into a new layer. ...
4
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3answers
77 views

From PostgreSQL to QGIS

I have conected to PostgreSQL and imported the layer to QGIS. The names of columns are written using English letters. Can the names of columns be automatically renamed using another language?