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

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QGIS, CRS's and metric measurements of distance matrix and nearest neighbour

I have thousands of points on a multiple layers and I need to get the distances between each point and every other point within a layer (so i can get min, max, mean and median distances) and the ...
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13 views

python Qgis : add labeling to a vector layer of polygon

I'm trying to add labeling to a polygons vector layer called "myVectorLayer". It does not give me an error but the labeling does not appear. palyr = QgsPalLayerSettings() ...
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1answer
16 views

Join Attributes by Location: .mdb and shapefile in QGIS

I can join attributes by location in QGIS using 2 shapefiles. However, I do not know how to do the join when one of my files is in a .mdb format while the other is a shapefile. Please advise?
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20 views

Rasterize shapefile using another raster's size and resultion

Rasterizing a vector (shp) I face the following problem: I want my output file (the rasterized vector) to have the same resolution and dimensions as an existing raster. If I understand the interface ...
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1answer
14 views

Not empty geometry having blank text

i'm having problem with geometry column, for some rows i have geometry with blank text, this query will describe more the problem : select geom, ST_AsGeoJSON(geom), ST_Isvalid(geom), ST_IsEmpty(geom) ...
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13 views

Some items have coordinates switched when loading PostGIS layers in QGIS

I am having problem with strange coordinates switching when loading PostGIS layers in QGIS. First, I thought, that problem may be cause by the use of GROUP_BY feature in layer query, but later the ...
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2answers
23 views

Incorrect display of national characters from Spatialite in QGIS, Windows

I used this tutorial by Underdark (thanks much :-) ) to convert my area of interest from OSM file (whole Czech Republic downloaded from Geofabrik.de server). Used OSGEO4W shell (saying "GDAL 1.11.0, ...
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0answers
19 views

GISBASE not set [on hold]

Hi am VERY new to all this. On Windows 7 and downloaded QGIS 2.4, I'm trying to follow a tutorial on how to manipulate Lidar data and have got to the "create new mapset" but cannot finish because says ...
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2answers
51 views

Relationship of QGIS to its sister programs?

I'v e been using QGIS 2.4 for a number of months now and we are using it a bit at work. I noted that when I did the initial install a number of new icons appeared on my desktop namely MSys QGIS ...
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22 views

Lining up three Layers that use same Coordinate Reference System (CRS) in QGIS?

How do you make all borders of a layer equal? they should be equal but i don't know how, mCRS layer is all in philippine zone 5(EPSG:3125), with the same formula/equation, I'm new to QGIS and I'm ...
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1answer
27 views

Merged Layers turned into square shape cause by single layers in QGIS?

What I did is merged the 30 layers of the map (Isabela Map Province - Philippines) and below is what happened. How do i remove the inside map of the border? I'm new to QGIS and I'm using QGIS 2.4 ...
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1answer
28 views

Can FileGDB SDK be made to support custom coordinate systems?

In May 2012, a question was asked about File Geodatabase (*.gdb) support in QGIS? In the comments there, it was pointed out by @MattWilkie that the FileGDB SDK does not support custom coordinate ...
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1answer
22 views

QGIS: Need to remove unwanted white bands when raster layer are overlapping

In my project when raster layers are overlapping a white band appears the edge of the top layer. How can I remove it and obtain a seamless overlapping of the raster ? (I have try to built a vrt with ...
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0answers
22 views

PyQGIS: Editable Combobox for Value Map widget isses

I am having issues with an editable combo box in QGIS 2.4. The edit widget is set to Value Map with an uploaded CSV. However, if a new values (not included in the key value pair list) is added, the ...
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1answer
36 views

Creating New Layer After Sorting Attribute Table using QGIS?

I have been self-teaching myself some open source GIS. I downloaded QGIS and have been following this four part tutorial - ...
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1answer
15 views

QGIS: how to identify a single raster layer on a big project?

I have QGIS project loaded with many raster files. For a given area I am looking to identify which (raster)layer provides the visible data. To start, I will already be happy with a manual solution. ...
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1answer
21 views

QGIS 2.4 Attribute Table Search Bar?

I am learning how to use QGIS and am following various tutorials. My version of QGIS (2.4) does not have a "look for" search bar in the attribute table window as seen in older versions in screenshots ...
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25 views

Obtain an altimetric map from a layer with lines

I have a layer with contour line and I need a map with polygons colored depending on altitude. Something like this The three shades of brown identify slope: absent, moderate or marked. I know ...
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25 views

Features in .shp can't be identified & won't render

Using QGIS 2.4.0 on Windows 7 Service pack 1. I have several .shp's, all polygons, that give me the following problem: 293 features are listed in the metadata and shown in the attribute table but the ...
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2answers
79 views

How to convert data from a .gdb into a shapefile without ArcMap?

I have a .gdb folder with LOCK Files, FREELIST Files, ATX Files, GDBINDEXES Files, GDBTABLE Files, GDBTABLEX Files and, SPX Files. I want to convert the parcel data within this folder into a ...
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1answer
20 views

How to export drivingDistance results in pgRoutingLayer on QGIS 2.2.0?

Hi and first of all congratulation for the great work on working and explaining the posGIS functions in QGIS : it makes this rich GIS enven richer. Thank's to Underdark's pgRoutingLayer extension, I ...
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1answer
58 views

How do you modify selected geometry with a function in qgis python console?

My example use-case is that I want to redistribute vertices along lines as in Redistribute linestring vertices to specified distance or How to create points in a specified distance along the line in ...
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1answer
31 views

How to do loops on raster cells with python console in QGIS?

I'm new here and beginner with python. I'm looking for a solution to my problem for some hours but now you are my last chance... I'm using the python (2.7.5) console in QGIS (2.4.0). Is there a ...
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0answers
16 views

Add a new polygon to an existing shapefile from wkt in QGIS

I have a layer of polygons in QGIS; I want to add programatically (pyqgis) a new polygon to this layer using WKT. Example: mywkt = POLYGON ((522762 376413 0,530635 368671 0,522237 353713 0,522762 ...
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2answers
37 views

python qgis 2.4 : display a view with symbology

I have managed to display a view created using postgresql from qgis using python code: uri = QgsDataSourceURI() uri.setConnection("localhost", "5432", "stat", "postgres", "admin") ...
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16 views

QGIS custom labeling by clicking on polyline (and polygon)

QGIS has now few really good options for custom labels but I can't find a way how easily manage labels along polylines. Is there any tool which helps me to place labels by clicking on polyline so the ...
3
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1answer
64 views

Saving selection as new layer in QGIS 2.4?

I've selected a number of polygons from one layer and want to create a new layer. Because I can't right click using a mac how do I find "Save Selection As". Its not in the list in the "Layer" ...
3
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1answer
45 views

How to display bidirectional flows?

I'm working on a map showing oil shipping. Basically, I have a a series of nodes/line segments that make up the shipping network. I've joined the sums of oil that traveled along each node, so can ...
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0answers
37 views

Editing the QGIS Attribute Table

Is there a way to edit the name, type and length given to each column on the attribute table once the information has been imported from Excel?
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0answers
27 views

Create global raster layer with latitude values of each cell in QGIS

I have a raster with a 0.0083 degree resolution (WGS 84) of which I need the area of every single pixel. An easy but compute-intensive approach is explained here but as I need to work with bigger ...
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1answer
21 views

Merge multiple linestring features into a single multilinestring

Using QGis or ogr2ogr how do I convert a vector file containing multiple linestrings features into a single multilinestring feature? At the moment I've been doing this manually by converting the data ...
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2answers
33 views

Error while importing CSV File using PyQGIS

Currently I am trying to import a CSV file using the python extension in QGIS and I have run into a problem that I can not seem to solve. I am trying to do a basic import of a CSV file from a python ...
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16 views

Can QGIS hyperlink polygons to link with a server?

I am trying to hyperlink a load of polygons to a set of files on a server (using the actions on QGIS). However, I can only seem to be able to link to files when they are either in by C: or online. Is ...
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0answers
61 views

Sourcing GIS data from First World War (WW1)?

Simple question, but does anyone know where I can get some detailed (eg 1:10m scale) vector data from the First World War? I've been through the archives here, but it seems the best sites for it ...
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0answers
7 views

QGIS web client: “Object Identification” initially toggled on

I'm running a QGIS web client and a QGIS server. I want to modify the initial settings of the QGIS web client so that the "Object Identification" mode is toggled on from the beginning (just like ...
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1answer
48 views

Georeferencing image using QGIS?

I am very new at this and when I georeference an image in qgis, I get the same image georeference but rotate and elongated. I use 3 control points to georeference the image but whatever I do, I get ...
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0answers
11 views

Is there any autocomplete filter widget for QGIS connecting to PostGIS?

In QGIS, there is Value Relation widget for fields, that contain references to data in external tables or views. While it works fine for small number of choices, it can quickly become overwhelming, if ...
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12 views

How to get sql error from postgis when a plugin fail to load vector layer?

I am writing a plugin for qgis that load a sql layer from postgis database. I am disappointed that when the layer fails to load i can't find a way to get the sql error message from database server. ...
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0answers
17 views

How to compare two sets of points in QGIS?

I have two point layers with XYZ data: 1 set are points measured at the field and the second set is a Lidar data set. I want to check the accuracy of the lidar in comparence to the measured data. Is ...
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0answers
27 views

Reading Points as PolyLines

I'm currently developing an Android app where I need to show some information on a map, which is stored as Shapefiles (.shp + .shx + .dbf). I noticed that when the shapefile is opened in QGis, a nice ...
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0answers
12 views

More than two level group on Lizmap WebClient

i can see level more than two group on lizmap plugin, but when i save for webClient, it just appears two level group on Lizmap WebClient legend layers area. i want to see on Lizmap WepClient like ...
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0answers
18 views

Import QGIS Python modules in Python command line or standalone script

I am running a Windows 7 machine with Python version 2.7.8 (32 bit). I installed QGIS 2.4 (Chugiak) from OSGeo4W and simply want to be able to import the QGIS Python modules (e.g. qgis.core) into ...
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0answers
24 views

Polygonize only pixel values of 1 from a raster

I have a raster mask that I have created in QGIS (2.2.0) that consist of 0, 1 and nodata values. I would like to end up with a polygon dataset that consist of only the value of one pixels from this ...
0
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1answer
48 views

Determining direction of longest segment of polygon?

I have a shapefile with 9000 agriculture fields and what I like to do is to determine for each field (=each polygon) the direction of the longest segment. For instance, the selected polygon in the ...
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2answers
24 views

How to extract a new linestring vector from a existing multipolygon in QGIS?

What I want to do: create a new line (named linestring in Postgis?) from existing multipolygon layer in Postgis. Purpose: once these lines are created, I'll run some distance calcs from specific ...
2
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2answers
51 views

Generating polygons with shared boundaries using QGIS?

Essentially the problem is that if you digitise each polygon separately the boundaries will not match exactly. My instinct is to have a table of line segments and generate the polygons from that using ...
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1answer
21 views

qgis printcomposer: can I select features whose attributes to show

I am using the atlas to generate a number of maps. Each map is of a particular zone represented by a multiline vector layer. I have another layer with point data and each map has an attribute table ...
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1answer
14 views

qgis printcomposer: can I wrap text in attr table?

I have some longish text attributes and when I try and put these on the map using the attribute table they get truncated. Is there a way to get these long lines wrapped.
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1answer
27 views

Have Atlas sorting and filtering controls been removed in 2.4?

In this diagram the atlas generation tab of the print composer has several controls that I don't see in my version (2.4) of QGIS. In particular the feature sorting and feature filtering, both of ...
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27 views

QGIS formats support [on hold]

Is there any plugin or any feature which will supports more formats than existing formats. Because ARCGIS has Data interoperability tool which can support same as FME Formats. Is there any thing ...