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

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1answer
322 views

how to create a map with oneway flows using FlowMapper for QGIS

my plan is to create a map that shows the top 50 (by amount of passengers) international flights departing the United States (e.g. New York -> London, Honolulu -> Tokyo...). I want to use the plugin ...
0
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1answer
56 views

How do I label my map with attributes?

help is always appreciated. I have a state map in QGIS 2.0 with all of the county names and some other info listed in the attributes table. I would like to have the name of the counties and one of ...
5
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2answers
283 views

Raster: mosaic first, or project first?

I have a thousand raster tiles in un-projected decimal degrees from which to build a seamless mosaic in a metres-based coordinate system. The final image will be about 70,000px by 50,000px. Which is ...
5
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2answers
705 views

Load and display a layer from SQL Server using PyQGIS

I'm having a go at using pyqgis from within the QGIS python console to load a layer from SQL Server and display it. I feel like I'm part way there but I'm having a real issue getting the layer to ...
2
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2answers
693 views

Conversion of Latitude/Longitude to different map projection

I have two m*n matrices coming from a WRF-ARW simulation: one exclusively with longitude values and one with only latitude values. For both matrices I know the originatin projection (lambert conic ...
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0answers
294 views

QGIS 2.2 saving layer as CSV with GEOMETRY=AS_WKT not working

Just upgraded to QGIS 2.2 and it looks like saving a layer as CSV doesn't support GEOMETRY=AS_WKT anymore. The new Layer Options portion of the save dialog is cool but it looks like GEOMETRY and ...
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1answer
145 views

data defined labeling with postgis layer

How to use the expression based (edit: data defined) labeling with postgis? I'm wondering, whats the best way to use expression based (edit: data defined) labels with postgis (I'm new to postgis). ...
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2answers
245 views

How can I add custom CRS with +proj=mercxx to QGIS 2.2.0 Valmiera?

i've builded a custom proj.4 library, tested it by command line (proj and cs2cs) and with postgres/postgis. All works fine. Now i'm trying to make the same with Qgis 2.2.0. I've replaced the original ...
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0answers
166 views

Bivariate Mapping (running a single variable regression and mapping r-squared value)

I am hoping to produce a bivariate map displaying the correlation between two variables (specifically percent SNAP participation by county against several social variables). I would like to produce ...
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2answers
573 views

QGIS Valmiera, Labels only show for part of polygons

Using 2.2.0-Valmiera on Ubuntu 13.10 I have for Croatia 21 Counties as polygons. Labels show only for 12 counties: here I see that no labels are shown for multipart features. So I checked "Show ...
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1answer
62 views

How to properly combine and export (as raster) vector lines on top of raster

I have a georeferenced TIFF with building plans on it. I then laid topo lines on top of it. it looks right in QGis. I now want to export this as an image (i.e. with the topo lines overlaid). How do I ...
3
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1answer
126 views

Is it possible to distinguish between points with the same coordinates?

I have several points with the same coordinates in one layer and of course they are located on top of each other. Is there a way to separate this points automatically (not manually)? I don't want to ...
4
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2answers
430 views

How to set the transparency for multiple layers or add a global transparancy preference?

How can I set the transparency to 27 % for all 245 layers in QGIS? The only way I know of is by right clicking on the layer name, selecting Properties, then Transparency and then moving the ...
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1answer
140 views

Display postgis data with qgis 2.2

I have a problem with some shapefile, PolygonZ type, I have imported with "shp2pgsql-gui". This is the output (note 'coord_dimension' value): mode=c, dump=1, simple=0, geography=0, index=1, ...
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1answer
2k views

Add file GDB in quantumGIS 2.2

In QGIS 2.2.0, while adding vector layer, 'ESRI FileGDB' option was missing under Source-Type, refer the attached screenshot.In this case, how can I attach a file GDB in QGIS 2.2.0?
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1answer
333 views

How to select by attributes and calculate aggregates using Modeler?

I need to know how I can select/aggregate equal attributes in a table. This is quite the same I want to do. But I want to do it with the modeler. How to group and count attribute data? The column ...
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1answer
333 views

QGIS 2.0 - can't select items in Print Composer

I am having an issue where I can create a print Layout in Print Composer, but once I have clicked away from an item (like map, legend, arrow, etc) I cannot select it again. Any pointers would be ...
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3answers
165 views

Invalid geometry message when using Difference tool

I am using the Vector \ Geoprocessing \ Difference tool to get the resulting area when taking a) current ground disturbance away from b) historic total ground disturbance to give c) what has been ...
17
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2answers
4k views

Does QGIS have the equivalent of ArcGIS's Layer (*.LYR) file?

Using ArcMap, it is possible to add a dataset (eg a shapefile) to the map, and configure the layer's properties (such as the symbology, table joins, switching some attributes off in the Identify ...
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1answer
463 views

How can I correct a .pgw file for a PNG image?

I have a PNG file and I need its .pgw file to be set with NAD 83 as the projection. I have created a .pgw file: 799 0 0 -799 -122.562 37.1946 However when I open the PNG in QGIS or ArcMap 10.2 it ...
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1answer
114 views

Is it possible to remove (Actions) and (Derived) from the QGIS Identify dialog?

When identifying a layer in QGIS 2.0.1 Dufour, the Identify Results dialog shows (Actions) and (Derived) keywords: Is it possible to remove these? Thanks
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1answer
31 views

How to select the identities of a layer present just in one identity of another layer

I'm a student approaching to QGIS 2.0.1-Dufour. My goal is to know how much identities of a layer are present just in one identity of another layer. I tried both with the tools "spatial query" and ...
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1answer
46 views

How can I locate additional GCPs?

I'm a new user of QGIS. I'm georeferencing a scanned image of topographic map. At least 16 GCPs were required for us to locate. However, only 12 can be located and can be identified and be defined ...
2
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1answer
314 views

Postgresql table won't display in QGIS 2.2

I just downloaded QGIS 2.2 to check it out and now one (just the one) of the tables from one of my PostgreSQL database won't display. It loads just fine in 2.0. The records are all there (there's ...
2
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2answers
341 views

Using Qt Designer to Create a Form in QGIS that can search for a specific point in a layer

I would like to ask if you can create a form in Qt Designer to create a form that can search for a point on the map using data that the user will provide such as the Name. I am currently creating a ...
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1answer
1k views

How to install OTB/Sextante plugin on QGis 2.0 (OSX)

I remember the Sextante plugin used to be available for my previous version of QGis. When I got a new computer however, I downloaded QGis again and got 2.0. Searching for "Sextante" or "OTB" yields no ...
3
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2answers
261 views

Merging DEMs of different grid size

I'm trying to merge two grids with different cell size. One has a cell size of 10m and the other 50m. The 10m one covers a subarea of the 50m one. I know that the most accurate one is the 10m one and ...
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0answers
30 views

Can I tell QGIS to load/show only a part of an image?

can I tell QGIS to load/show only a part of an image without to extract this region as an extra/ new image?
2
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1answer
116 views

Smooth out lines in QGIS

I have taken a raster image and coverted it to a vector file. It is an OS map which shows field boundaries etc. As the vector file has been created from the pixelated raster file the lines are ...
0
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0answers
68 views

Alternative to Snap (Editing) in QGIS/MapInfo?

Is there any alternative to Snap (Editing) in either QGIS or MapInfo (user-made tools), or another way to do this in ArcGIS without an advanced license?
9
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1answer
327 views

Is there a simple way to sort layers alphabetically in QGIS?

I am working on a big GIS project and not being able to sort the items in the Layers panel is giving me hard time. I can have up to 250 layers in the Layers panel. I have a special naming scheme for ...
2
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1answer
61 views

Identify geographic location to points

I am quite new in QGIS and I really need your help. I have a map of Kenya divided into 68 districts and I have coordinates of 30.000 schools. The points have one variable besides the latitude and ...
2
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0answers
53 views

Refreshing MSSQL Layer in QGIS

When working on a map in QGIS I will often set up a view in my SQL Server spatial database and create a MSSQL layer based on this. As part of my workflow I often make adjustments to the SQL view ...
2
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1answer
274 views

QGIS 2.2 rendering problems

i have a problem with some geometry. When i run the check geometry validity i get an error coming back that the rings are not closed, so recangular forms that i have surveyed are showing up as ...
2
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1answer
142 views

How to call a method by BOTH a button AND a key shortcut

I have been trying to call a method by BOTH a key shortcut (as described here http://www.qgis.org/en/docs/pyqgis_developer_cookbook/snippets.html) and a button I created on the toolbar. The button ...
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1answer
179 views

Line bearing for wind direction for plume of smoke QGIS

I'm trying to draw a line representing direction of a plume of smoke for an emergency planning scenario in QGIS. The line needs to be 5km in length and have a bearing of 85 degrees. The closest I have ...
0
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1answer
103 views

Count points within a given distance of a border

I have a vector layer of counties in Florida and a layer of points. I want to count the number of points that lie within 10km of the boundary for each county pair. This is what this looks like in QGIS ...
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1answer
154 views

Is it possible to run qgis through python?

I need to build an app to analyze some raster layers in qgis. I thought it was possible to just write code in python (2.7.6) (IDLE) and let it automatically open QGIS, load some layers, do a distance ...
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1answer
213 views

How to handle QGIS 2.2 Data Defined Label Position on PostGIS Layer Null Defaulting to 0?

I just upgraded to qgis 2.2 from 2.0. In 2.2 there was a minor change to data defined label positioning at least when used with postgis layers. In Version 2.2 the labeling engine appears to be ...
0
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1answer
235 views

Error in QGIS 2.2 Raster Merge Tool in OS X

I'm having this strange error in QGIS 2.2 for OS X while trying to run the raster merge tool (in the Raster - Miscellaneous - Merge). This happens just by clicking on the "Select" button to choose the ...
0
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2answers
433 views

Best way to create/draw a map (especially indoor)

I'm currently developing an indoor map/room plan for an university project. I've already searched through stackexchange to figure it out but I couldn't find anything similar. So what I currently do ...
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1answer
2k views

Create a hyperlink to a pdf file in the attribute table [duplicate]

I want to add a hyperlink to a pdf file into the attribute table of a vector layer. I already read the documentation about evis and the answered questions about this here. It didn't seem difficult, ...
0
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1answer
198 views

How to create a slope map with different colors according to slope percentage or degrees

I have converted a dxf file with contour lines into a polyline shapefile, and I have used the Raster Analysis plugin to create a grayscale slope map from this shapefile. I would now like to have ...
0
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3answers
91 views

How create geographic column in postgis table?

I merged several point shape files in postgis, but when I load the new merged shape in QGIS it is not possible to see points in the main window. To create the merged table I used this piece of code ...
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0answers
26 views

I want the coordinates of my polygon grid to change when I zoom

I want the coordinates of my polygon grid to change when I zoom into my map and produce different data outputs in my attribute table so that my lable can show accurate values of the points within that ...
0
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1answer
115 views

Python Built-in Map and Zip function in QGIS 2.0 Processing Script--syntax error

I am attempting to run my Python script using the Processing Toolbox in QGIS 2.0. I've used the built-in Python function map() and zip() several times and am now receiving a syntax error even though ...
0
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1answer
128 views

Programmatically modify attributes for vector layer in QGIS

I am trying to programmatically modify attributes for a vector layer, using calculated values currently stocked in a dictionary. Any pointers on where i'm going wrong? my dictionary has the feature ...
2
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1answer
104 views

how to use custom fonts in QGIS mapserver on Debian Linux

I've got a QGIS setup running, except for the custom fonts. They work just fine on my desktop machine (OS X), but they don't work on the server (Debian Linux). I've got the .ttf files installed in ...
5
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1answer
184 views

How to change OpenStreetMap Layer Properties in QGIS 2.0

I have loaded the OpenStreetMap layer in QGIS 2.0, but would like to edit the properties in order to better complement the map I'm producing. I can't seem to find the OSM toolbar or OSM Feature widget ...
3
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0answers
761 views

QGIS cannot open output layers

I have problem with QGIS 2.0.1. Everytime I run tool from SAGA or GRASS, I get exactly the same error, for example: Oooops! The following output layers could not be open Channel Network: ...