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

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0
votes
1answer
263 views

QT Designer form - Combobox stores value but doesn't display it

I have a custom form created with QT Designer on which I have several comboboxes among other stuff. All the fields have the correct names corresponding to the database. One of these comboboxes has a ...
0
votes
1answer
130 views

Duplicate values in combobox in QT Designer form

I have a custom form created with QT Designer on which I have several comboboxes among other stuff. All the fields have the correct names corresponding to the database. But something weird and ...
4
votes
2answers
245 views

Migrate to QGIS?

Is it sensible for me to migrate to QGIS? I've been using OCAD, a very old vector based map software to maintain a local "back country" map. With OCAD6 I initially import base data, e.g. contours, ...
2
votes
1answer
411 views

Failed load delimited layer in QGIS python console

I'm trying to follow the map rendering section from the pyqgis cookbook. I am able render shape file using qgs vector layer, however getting error prompt while loading delimited text file through qgs ...
6
votes
1answer
247 views

GDAL equivalent of ArcGIS Mosaic

The word 'mosaic' is often used for quite different things within the worlds of ArcGIS and GDAL. With GDAL and it's downstream applications like Qgis it is common to see mosaic used in the context ...
0
votes
1answer
33 views

When styling with data defined properties or Labeling, Is there a way to replace an ID representing field with the actual values depicted by the ID?

I am currently using data defined properties and labeling to present pipes based on diameter. I now have a dictionary table that has id's for every combination of diameter and material and I'm using ...
0
votes
1answer
132 views

Labeling expression to label one value in a attribute table column

I am using QGIS 2.0 on Windows. I have a shapefile for a point layer that has the the following attribute table: I am trying to label using the Status column and only want the value that equals ...
1
vote
1answer
125 views

using postgis function in pyqgis

I'd use Postgis function in Pyqgis script. This code: qsql="(select gid, id, St_Buffer(the_geom,200) as geom from archi)" uri = QgsDataSourceURI() uri.setConnection("ip", "port", "x", "x", "x") ...
1
vote
0answers
144 views

PyQGIS Dialog Plugin not resetting

I have written a PostGIS search plugin that works pretty well, except two things that I just cannot figure out a solution 1) When the dialog closes and then is reopened the previous query is still in ...
0
votes
1answer
227 views

Calculating distance between coordinates [duplicate]

I would like to calculate the distances between a list of coordinates (classic GPS coord.). From coordinate A to B from B to C from C to D and so on, and so forth. Is there any program, or website, ...
0
votes
0answers
27 views

The graduated symbology doesn 't take into account the attribute I need in QGIS

I m working on a project on QGIS I have a point shapefile vector that represents my store In the attribute table, i have bunch of data such as size, unit per transaction and most importantly store ...
1
vote
1answer
433 views

Editing WFS with max feature limit in QGis

I'm serving a large layer (500 thousand polygons) using Geoserver WFS and what to be able to edit it using QGis. I've set a feature limit on the layer so I wont overload GeoServer with the request. I ...
2
votes
4answers
619 views

Combining different geometry types into same feature class?

I've searched the question in this blog. Maybe I don't use the right words but anyway my problem is not present in any post so I'll try to explain my question by opening a new one. I have a polygon ...
1
vote
0answers
190 views

Zoom to Selected Feature for point layers in QGIS 2.0

I find the QuickFinder plugin for QGIS 2.0 very useful to quickly search, find, and select data. However, I'm under the impression that checking the "scale" option doesn't seem to do anything. I ...
1
vote
1answer
384 views

visualize bounding box to a polygon

I try to make plugin in QGIS that compare 2 bounding box data, ex: (-32.61442167739459, -32.017601026186576, 13.015663782506067, 13.428145228091406) and (-38.6102467739459, -38.017601026186576, ...
1
vote
1answer
510 views

Code works on python console in QGIS but same doesn't work in stand alone script

I'm trying map rendering with stand alone script, so I have small script which works fine in python console provided QGIS, however when I run same code in stand-alone script it executes without error, ...
1
vote
0answers
26 views

Able to circumvent QgsCredentials script called from Pre-execution

I've got a stored project that, when opened is connecting to my PostgreSQL DB, and is loading several layers. All good. I'm using a script that is called from Pre-execution (Processing/Options and ...
1
vote
0answers
31 views

What can I do in qgis to manage a WMS frequently unreachable?

In my project I have a layer linked to an external WMS server (provided by a local institution). The problem is that it is somewhat unreliable: it is down rather often. Is there something I can do to ...
1
vote
0answers
212 views

How do I catch PostGIS/PostgreSQL RAISE messages in QGIS?

I have a trigger set up in PostGIS/PostgreSQL which will show a RAISE WARNING when an inserted or updated polygon is within a certain distance of some predefined planning constraints. I want this ...
1
vote
4answers
459 views

How to change a CSV layer attribute value from text to number - once again?

i have read most of the related postings and answers allready ... (e.g. http://anitagraser.com/2011/03/07/how-to-specify-data-types-of-csv-columns-for-use-in-qgis/ and How to change a CSV layer ...
1
vote
3answers
116 views

How to add data to an attribute table?

I have a shape file (points) and would like to add points using the attribute table and not the Add Feature tool at the main screen. I went over the Qs here, but didn't find a similar problem to ...
-1
votes
1answer
1k views

QGIS v2. Convert longitude/latitude to UTM projection-Zone 51J - Southern hemisphere [duplicate]

Could somebody please let me know in QGIS version 2.0.1 How do I convert Longitude/latitude default setting to UTM projection. I am bringing in waypoints from a GPS device which is set to the above ...
0
votes
1answer
77 views

QGIS-Processing GRASS-tools don't work

When I try to use the processing grass tools like r.series I always get the following messege. I deinstalled QGis and reinstalled the program totally fresh without success.
1
vote
0answers
8 views

Simple solution for escaping the QGIS locked into fullscreen mode on Ubuntu 12.04 [duplicate]

" No crash in this case, but I made the mistake of toggling to fullscreen mode on my netbook running Ubuntu 12.04. It's now impossible to escape this "No Menus" view, and it seems to have disabled ...
1
vote
1answer
126 views

Can one batch-automate the creation of QGIS heatmaps?

I have 4k point shapefiles, from which I would like to generate heatmap TIFFs using the QGIS heatmap plugin (or a functional equivalent featuring triweigth, radius and cell size selection). Is there ...
0
votes
2answers
120 views

What output colour format is expected by the QGIS data defined properties widget?

I'm trying to write a python function that takes a BGSREF attribute from a BGS geology shapefile and uses it to colour up the geology polygons of a shapefile. I posted my non-code working as a part ...
0
votes
0answers
89 views

Turn vector layer in raster layer based on cost

Hy, I am trying to rasterize some vector layers into raster layers and I know this is possible with QGIS by using the rasterize function in the raster menu but I don't know how to do the following ...
0
votes
1answer
319 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
76 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
62 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
811 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
votes
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
110 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
714 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
91 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
171 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
197 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
165 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
896 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
146 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
885 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
285 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
626 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
516 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
266 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
114 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
226 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
147 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 ...