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

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0
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1answer
288 views

How can I change the precision in the attribute table?

I'm working with QGIS, v. 2.0.1. I opened a csv-table (from an Excel-file) and now the precision is very high but I don't need this. At the moment the values are for example 15.00000000000000, how ...
1
vote
1answer
50 views

Tick boxes for a qgis plugin written in python

in a python plugin for qgis I want the user to be able to select one or more of several options via tick boxes. I imagine it to look like e.g. Qgis 2.2 tool "Vector" -> "Data Management Tools" -> ...
0
votes
1answer
74 views

Best, fast and easy way to print multiple polygons?

I´m almost sure that this is to tricky to solve. Often I have multiple combined polygons that I want to print. Until now I´ve devided all the polygons by the "Split vector layer", because I need to ...
1
vote
1answer
59 views

GEOTIFF Binary File with Color Display Issues

I have a GEOTIFF in QGIS that shows values of 0 and 1 and I want the 0 values to have no fill so that background vector layers can show through and so I can easily overlay things in a print composer ...
2
votes
1answer
771 views

Using Affine Transformation to expand polygons in QGIS

I have a shape file, and I'd like to grow each feature by 13.7% or 14%. The program crashes every-time I try to use affine transformation. Any recommendations? I don't have a license for ARCgis. ...
0
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0answers
39 views

I want to reproject data from 0-360 to -180 - 180 [duplicate]

I've been downloading data from NOAA in a CRS that goes from 0-360. The rest of my data is in -180 to 180. What's the easiest way to reproject or shift the data in QGIS? It took 30 seconds in ArcMap, ...
0
votes
1answer
105 views

Create transparent background for svg marker in QGIS?

I have an image that I want to use as a SVG marker in Print Composer. I created it as a .png file in Inkscape and then saved it as .svg. But the background transparency does not come across from the ...
0
votes
2answers
664 views

How to join MySQL database to QGIS polygons

I Have an *.sql file that has no spatial information. For every record there is an id. I also have a Qgis project with polygons without any id. How can i connect the polygons with the database? I ...
1
vote
1answer
90 views

QGIS combine Vectorlayer and Rasterlayer to one shapefile

I have to create some Thematic Maps, especially Choropleth Maps on Matlab. Therefore i've found a shapefile which I can use, but need to draw some lines there. I've imported my shapefile as a Vector ...
2
votes
1answer
170 views

QGIS 2.2 documentation

I thought I would try to write a plugin for QGIS (some Python code that I hoped I could easily port) I started following http://www.qgisworkshop.org/html/workshop/plugins_tutorial.html but that turned ...
1
vote
1answer
189 views

pgrouting unexpected output

Thats my ways.shp file. I loaded this to PostgreSQL DB using PostGIS shape file loader. I ran pgr_anlayzeGraph() on it and found it had a lot of isolated segments. Next I ran pgr_nodeNetwork() to ...
4
votes
1answer
159 views

four color theorem for QGIS 2.0 or Leaflet?

I recently looked at some other posts relating to this topic but as far as I can tell there is currently not a working plugin or script for QGIS 2.0 to achieve a four color theorem for styling polygon ...
3
votes
3answers
845 views

Per-pixel (statistical) calculations on a raster stack using GDAL

In R, it's relatively trivial to perform per pixel calculations based on a raster stack (e.g., get std.dev for each pixel on a 12 layer GeoTIFF). Unfortunately, the speed is less than desirable when ...
0
votes
1answer
142 views

gdal's polygonize function (via qgis) is not turning monochrome rasters into readable shapefiles regardless of inversion of color scale

I've tried polygonizing this monochrome bitmap as this: and this: and either way it ends up looking like this when (zoomed in) after gdal's polygonize operation: Is there any way I can tell ...
1
vote
1answer
849 views

QGIS 2.2.0 install via OSGeo4W overwrote/lost qGIS ver. 2.0

Just installed ver 2.2.0 Valmiera through the OSGeo4W advanced installer for a test drive. It overwrote existing ver 2.0 in the process. Still want to have the previous to work from. How can i get ...
1
vote
1answer
273 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
votes
1answer
53 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
votes
2answers
604 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
votes
2answers
489 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 ...
1
vote
0answers
262 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 ...
1
vote
1answer
108 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). ...
1
vote
2answers
222 views

Add custom CRS - 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 ...
2
votes
0answers
144 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 ...
1
vote
2answers
514 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 ...
2
votes
1answer
55 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
votes
1answer
111 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 ...
3
votes
2answers
255 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 ...
1
vote
1answer
137 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, ...
1
vote
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?
2
votes
1answer
240 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 ...
0
votes
1answer
282 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 ...
1
vote
3answers
150 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 ...
16
votes
2answers
3k 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 ...
0
votes
1answer
334 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 ...
2
votes
1answer
105 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
0
votes
1answer
29 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 ...
0
votes
1answer
43 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
votes
1answer
280 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
votes
2answers
251 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 ...
1
vote
1answer
987 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
votes
2answers
220 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 ...
1
vote
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
votes
1answer
81 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
votes
0answers
62 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?
7
votes
1answer
247 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
votes
1answer
60 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
votes
0answers
45 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
votes
1answer
251 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
votes
1answer
131 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 ...
1
vote
1answer
146 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 ...