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

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1answer
101 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
102 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
98 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
178 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 ...
4
votes
1answer
76 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 ...
1
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0answers
92 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
47 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
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1answer
124 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
101 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
96 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
113 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
47 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 ...
2
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0answers
83 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 ...
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0answers
49 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
105 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?
4
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0answers
163 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 ...
3
votes
2answers
112 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
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0answers
44 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
4
votes
1answer
125 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 ...
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0answers
39 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 ...
4
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2answers
226 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
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0answers
43 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 ...
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0answers
106 views

Query PostGIS database without creating primary key [closed]

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 ...
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2answers
2k 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 ...
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0answers
51 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 ...
3
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1answer
1k 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
166 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 ...
6
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1answer
161 views

How to create a storm swath map?

I can't really find the words to explain what I'd like to achieve so I attached a picture. The top picture was made of two layers, the layer with circles was made/styled using the instructions from ...
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3answers
101 views

How to delete horizontal lines from a vector grid?

I have a 250ms vector grid which covers an area of 88 Sq.kms. For surveying purpose, we would like to retain the vertical lines alone. Is it possible to delete all the horizontal lines from the grid ? ...
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0answers
28 views

How to import PDF which has vector format into QGIS's vector layer? [duplicate]

I know the way to convert an ordinary raster pdf into QGIS. But is it possible to import a pdf which preserved the vector format (e.g. the pdf files exported by AutoCAD) to QGIS's vector layer?
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0answers
21 views

Free And Open Source Software Tools to orthorectify Pleiades imagery [duplicate]

Are there Free And Open Source Software Tools to orthorectify Pleiades, Worldview And Quickbird imagery as we do with COST tools such as ERDAS Imagine, PCI, ENVI, etc.?
2
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0answers
233 views

Postgis / QGIS Snap Point to Line

I'm trying to snap points to lines in postgis for use in QGIS, but cannot get it to work. I have one line in my line table (although it was created by merging multiple lines together) and about 600 ...
4
votes
1answer
87 views

Adding super/sub script in QGIS text annotation?

How can I add a super/sub script in a QGIS text annotation? For example, 44.95 mi^2.
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0answers
774 views

QGIS 2.4.0 Mac Yosemite compatibility

I just upgraded to the Beta 2 version of MacOS 10.10 ("Yosemite"). I'm getting an error when I try to "drag and drop" shape files into QGIS. I'm running QGIS 2.4.0, GDAL 1.11, and MATPLOTLIB 1.3.1. ...
2
votes
1answer
145 views

QGIS way to import OSM/Google Maps but remove or exclude extraneous areas, limit geographically the use of OSM

GIS Newbie question, perhaps: But I am looking to place an Open Street Maps/Google Maps layer underneath the rest of my shapefiles for referencing purposes. Let's say for instance, that I am looking ...
2
votes
3answers
328 views

How to measure correct distances in a project with OpenLayers background?

I have 3 lat/long points as follows: A = {35.257246,139.721256} B = {35.256541,139.721491} C = {35.256326,139.7203271} 1) Measurement result by Movable Type Scripts: By using the distance ...
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0answers
149 views

Using two different Python versions for QGIS scripting?

I´m intending to learn scripting with python in QGIS, but I have a couple of questions. I'm using Python 3.4 for learning which is installed in my laptop, but QGIS is using Python2.7 How could I ...
1
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1answer
207 views

Box cropping shapefile based on particular latitude and longitude using QGIS? [duplicate]

I have a shapefile and I need to crop/clip it based on a rectangle of particular latitude and longitude using QGIS. If it is possible, how do I do that?
0
votes
2answers
249 views

Conflicts while installing postgresql9.3-postgis2.1,QGIS and gdal-bin

I want to use postgresql9.3-postgis2.1 and gdal-bin parallel . I have refer instruction here for installing postgresql-9.3 on ubuntu 12.04. I have install qgis from here While installing gdal-bin it ...
1
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0answers
47 views

QGIS fTools very slow adding random points?

I am currently on windows 8.1 qgis 2.2 and almost everything I am trying to do using ftools is too slow. For example: using divaGIS world countries layer (.shp) when I try adding 500 random points ...
4
votes
1answer
611 views

Draw lines between two points in QGIS

I have an excel (Fig) which has both X & Y in projected coordinates (WGS84/UTM). Is it possible to draw lines between the X & Y in QGIS ? I've tried to create points based on X,From_y and ...
2
votes
2answers
103 views

Parse Field to Select Records

I wish to select records based on the NRN attribute in my dataset : "NRN" IN ('1','2','23','31') Some records have multiple values in the NRN field separated by the underscore character. For ...
2
votes
1answer
215 views

How to add buttons to QT ui for qgis feature forms to loop through attributes?

I'm looking for a bit of guidance. I'm happy creating a standard feature form using QT designer (as excellently documented here) for QGIS but I was wondering how you add a forward and back button to ...
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votes
1answer
168 views

Identifying projection for shapefile with unknown coordinate system, no z values and no measures? [duplicate]

I am attempting to create a GIS Project with multiple Brazilian cities. I have been collecting, and am interested in, shapefiles that delineate the neighborhood boundaries of said cities. One city's ...
2
votes
1answer
63 views

How to cover a number of points with disks?

I have to cover some points with disks. These disks are not of a fixed size, they have to constraints: a maximum diameter, and a maximum number of points covered. I would like to ...
1
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2answers
451 views

How to create spline in QGIS [closed]

I want to create spline in QGIS. I have tried to use Cad-tools - Create spline line\poligon but I can only draw it and can't save. What is wrong I am doing? Is there other way to create spline?
2
votes
0answers
322 views

QGIS 2.4 Processing (Zonal Statistics) error

In QGis 2.2 all my models (processing model builder) are working fine. When I start the same models in 2.4 I get errors like this: Prepare algorithm 5: Zonal Statistics Running Zonal Statistics ...
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2answers
253 views

Tiled raster image to be placed in an OSM/ Leaflet.js map

I have a mapoverlay in a custom projection which I need to add as a layer to an Openstreet map within a website. Since I was not able to change the projection earlier, I decided to manipulate the ...
1
vote
1answer
143 views

How to scale with radius attribute

new user of QGIS. I would like to style vector data based on an attribute (radius). The actual unit is in nautical miles. I don't want to use size-scale field or buffer to style the point rather I ...
2
votes
1answer
192 views

Why is feature.geometry() None in my user-defined expression function?

I'm trying the user-defined expression functions for QGIS, as listed on Nathans blog: http://nathanw.net/2012/11/10/user-defined-expression-functions-for-qgis/ I always get the feature.geometry() as ...