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

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6 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 ...
1
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0answers
19 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
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1answer
19 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: ...
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0answers
17 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
29 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 ...
2
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2answers
30 views

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

I recieved 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
30 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 ...
2
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2answers
157 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
9 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 loading always the same html file for all of them? Best Regards
1
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2answers
53 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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0answers
15 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
18 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
votes
1answer
289 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
10 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
votes
2answers
50 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 ...
1
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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
34 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
30 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 ...
2
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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 ...
1
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0answers
19 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
22 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
11 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
40 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
50 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
0answers
17 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
37 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 ...
2
votes
0answers
35 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.
1
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0answers
29 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: ...
1
vote
1answer
42 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
29 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 ...
1
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0answers
27 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 ...
1
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0answers
22 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 [on hold]

Are there any plugins in QGIS for solution of geodetic problems, construct serif?
1
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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
votes
3answers
76 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?
2
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0answers
26 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 ...
1
vote
2answers
29 views

How to extend grid lines (Survey traverse lines) created by vector grid tool in QGIS?

We have a polygon. We want to create a grid (sort of) with certain intervals, lets just say - 200ms. In QGIS, using "Vector grid" option we can do this. But, once it's get clipped, it's like Fig -1. ...
2
votes
0answers
11 views

QGIS 2.4: make an image-to-image registration to link the 2 images (RGB AND NIR)

I have 2 images (RGB and NIR) in png form from field and i need to link them together somehow to be able to see the overlapping areas, and cut out the wrong ones. How to do this with QGIS 2.4.0
3
votes
1answer
27 views

QGIS 2.2: prevent labels being cut off / clipped at edge of map

I've read a few other issues about trying to prevent labels from rendering if they run off the edge of the map canvas. This is particularly a problem in Composer, where I get lots of country labels ...
1
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0answers
29 views

How to extract elevation data from ASTER/SRTM? [duplicate]

I just want to know if there are any other tools available in QGIS apart from the Point Sampling tool to extract elevation data from ASTER/SRTM/CartoDEM (for India) data? When I convert these images ...
3
votes
2answers
42 views

Layer just for annotations

Im relatively new to QGIS and would like to know whether or not I can save my form annotations to a layer so I can turn them on or off.
2
votes
0answers
19 views

Working with Fulcrum data in QGIS

I have been sent some shapefiles, gathered using the Fulcrum app. However, when I load them into my project on QGIS 2.2, they wont display. They will display if I go to 'Zoom to Layer Extent" but ...
1
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0answers
22 views

Query PostGIS database without creating primary key [on hold]

I'm trying to query PostGIS database from QGIS DB Manager: select row_number() OVER(ORDER BY idx DESC) as id, p.*, * from table_1 join table_2 as p on "name" = "name" where row_number() OVER(ORDER ...
4
votes
2answers
70 views

QGIS 2.4.0 How to display only selected features on map?

Not sure if this option ever existed, but the new QGIS version hides a lot of things somewhere else and this seems so simple that I'm kind of convinced it was possible to do this before. I have quite ...
1
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0answers
37 views

Join/append multiple, identical polygon layers into a single layer whilst retaining all attributes?

I have run some analysis (zonalstats) on different raster layers using the same analysis polygons. I want to concatenate all these different layers together, i.e. retain a single polygon and have a ...
2
votes
1answer
42 views

Trying to install QGIS - missing 1.11 GDAL

I just spent the last n hours working on this, and still haven't gotten anywhere, so I'll throw it to the group. I see that other people have asked about this here and here, and I'd be happy to take ...
3
votes
2answers
64 views

Merging raster and vector not working

I have 1 vector layer (counties) and 1 raster layer (population density). I have tried merging these two, so that I can examine population density within a county, but I have had no luck. It just ...