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

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1
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1answer
139 views

Taking a 'custom' map and transforming its x/y co-ordinates to 'real' long/lat co-ordinates?

I was wondering if someone could help me out with a little project I'm working on. I'll try to describe what I'm trying to achieve - if it doesn't make sense, please let me know. I have in front of ...
2
votes
1answer
3k views

How to setup QGIS Web Client?

So we've installed QGIS Server and things look to be working well (thanks Underdark for the great tutorial). Next up we want to get the QGIS Web Client working. It appears we're missing a step or ...
3
votes
0answers
240 views

How to symbolize vector features using RGB values stored in three fields?

I need to symbolize a vector layer in Arcmap based on RGB (or HSB - can do either) values found in fields in the attribute table. I'm working with up to 10 different datasets, each with over 100 ...
3
votes
1answer
1k views

How to use field calculator from QGIS Sextante plugin

I am trying to use the Sextante field calculator to calculate a field for a buffer radius using a categorical text field. The formula works fine when I run it using the standard QGIS field calculator ...
2
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0answers
43 views

How to set different label content for different scales? [duplicate]

Possible Duplicate: How to accomplish conditional labeling based on map scale and attribute in QGIS 1.7 I'd like to show different label content at different map scales. Zoomed in, I use ...
5
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2answers
455 views

How to accomplish conditional labeling based on map scale and attribute in QGIS 1.7

How can I label with qgis 1.7, based on attribute and scale of map? For example scale>1:1000 then label all those features whose area>100000 at font size 12 and those features whose area<99999 at ...
16
votes
1answer
182 views

Can we create views over a raster table in Postgis2.0?

Is it possible to create PostgreSQL views over a table that contains raster data? I have succeeded in creating the view but the entry in raster_columns is not correct (all the raster info is ...
5
votes
0answers
329 views

Can Quantum GIS replace Proprietary GIS? [closed]

I’m an MSc GIS student in the final year of my studies. I’m researching for my dissertation project which is entitled ‘Can Quantum GIS replace Proprietary GIS in large organisations?’ I’m primarily ...
4
votes
2answers
789 views

How to show a message box in QGIS?

I am starting to develop a plugin for Qgis using python, which i am very new at, and would like to view some results of variables by displaying a message in QGIS. How can I do this?
3
votes
1answer
534 views

Qgis problem clipping a raster .asc file, the output is unreadable

I am currently using QGIS (1.8.0) to prepare files for use in MaxEnt to predict species distribution in a new territory in Argentina. I need to a) cut the raster files (bioclim, and others) to a ...
9
votes
3answers
860 views

What are common methods for converting raster digital elevation data to vector contours?

In researching this I have found many references to the opposite, creating elevation data from contours, but nothing regarding contour creation. Preferably, I am looking for open source solutions like ...
7
votes
1answer
253 views

How to see what lines have changed in an updated Shapefile?

I'm using my county's GIS data to update the roads in OpenStreetMap. I have a copy they published last year and one that was just published, and I'd like to find all the LineStrings that have either ...
2
votes
1answer
869 views

How to change 2 rasters to have the same dimension?

I am new in Quantum Gis 1.8 and have the following problem. I have extracted two raster files(land_cover.asc and soil.asc) using a polygon of my study area (area.shp) Apparently the raster dimensions ...
2
votes
0answers
102 views

How to install QGIS on Linux NAS using IPKG

I have a Linux -Based NAS that I want to install QGIS onto. Since I am administering through a web interface from a Windows based PC, how can I install qgis? Is there a way maybe through IPKG? Or any ...
5
votes
3answers
1k views

How to split lines on vertex?

I've searched a lot but didn't find an answer: When editing lines with QGIS, I often need to split a linestring exactly on one of his existing internal vertices, but I can't find a way; I've tried the ...
4
votes
2answers
1k views

Shape-file encoding problem in QGIS 1.9.0 (built with GDAL 1.9.2)

I have googled a lot but failed to find the answer. My configuration is: Ubuntu 11.10 Quantum GIS - 1.9.0-Master 'Master' (caae7b7) GDAL 1.9.2, released 2012/10/08 Shape-files refuse to open in ...
2
votes
1answer
134 views

How to hide all fields at once in QGIS 1.7

Is there a way to hide all the fields at once in QGIS 1.7? I see where I can hide one field at a time but I would like a button which does it all at once.
7
votes
2answers
293 views

How to run a spatial query with a raster and vector layer in QGIS?

I have a soil map (vector-polygon layer) and a map of the crops farmed in the same area (raster layer, from the US Cropland Data Layer). I would like to calculate for a given soil type, the surface ...
3
votes
1answer
89 views

How to display the label with “Identify Features” in QGis?

I have been struggling for one hour with this simple problem : I have a raster layer. I would like to display the label and not only the band value when I use the "Identify Features" button. Is it ...
3
votes
1answer
2k views

How to export shp to kml?

I already browsed your FAQs, and could not come up with a good answer, I am trying to export shp files to kml to be placed on Google Earth. On a previous version of QGIS it was as simple as right ...
3
votes
1answer
167 views

How to get raster layer pixels contained in a shape defined in a vector layer

I am new in QGis python plugins dev and I have a "maybe stupid" question (in the title :-) ). I try to retrieve pixels (from a raster layer) which are "contained" in a polygon defined in a vector ...
6
votes
1answer
9k views

How to crop Shapefiles in QGIS?

I need to clip a large and very detailed .shp file in QGIS showing environmental data similar to a temperature map. Is there something like the very simple crop tool alike in photoshop where you can ...
3
votes
1answer
425 views

Why are the polygons in my GML not rendered?

I tried to view GML files from download services ( http://services.cuzk.cz/gml/inspire/cp/epsg-5514/ ) and I have a problem with viewing of polygons from layer "CP:CadastralParcel". This Layer ...
5
votes
3answers
165 views

How to make same installation on multiple machines?

What is the easy way to make the "same" Qgis installation (same menu, same plugins, same prefs...) on multi-PCs, 10 or 12 laptops ? thanks for your help.
9
votes
4answers
5k views

Tutorial on how to model flooding using data from gauging stations along rivers in QGIS?

Can someone please direct me to a tutorial where I can learn more about how to model flooding using data from gauging stations along rivers using QGIS?
2
votes
1answer
222 views

Visualizing KMZ network link in QGIS

Is it possible to open and visualize and kmz network link in QGIS. If so what are the setps involved? Thanks in advance Cheers
11
votes
2answers
943 views

polishing qgis map for publication using inkscape

I have a problem modifying the map I created in QGIS. I need to add some text on the map and axis labels. Apparently, labels cannot be rotated in qgis, so this I need to do in inkscape or in a related ...
3
votes
1answer
447 views

Can I disable mouse wheel zoom in QGIS?

I am having problems with the zoom in QGIS 1.8.0 where a slight move of the scroll wheel on the mouse zooms way way out. It will re-render at each zoom level and with large datasets it takes over the ...
3
votes
0answers
185 views

How to debug Quantum GIS PlugIn Visual Studio DLL?

I develop a Quantum GIS plugin layer using Microsoft Visual studio and placed it in my plugins folder of my customized quantum gis application. I now intend to debug the DLL using Microsoft Studio. ...
8
votes
3answers
1k views

How to fix “Unable to initialize ODBC connection to DSN for ALC_AV_CO”?

So I am new to the QGIS community, and I have been trying to bring in some rather large access databases with little to no success. I have windows 7, so I've gone in through administrative tools/Data ...
6
votes
3answers
587 views

How to extract area programmatically?

is there a possibility to extract the area covered by one geometry of a shapefile (polygon)? I tried with thepoly.area() but get "nan" as result. Ok. I think you are right and there is ...
2
votes
0answers
396 views

Is there an Offset function in QGIS for Polygons?

IS there an offset function in qgis similar to that in autocad for polygons. I have an irregular shaped pollygon which i want to offset at 100m out from the edges, effectively adding 100m out each ...
5
votes
2answers
3k views

How to install QGIS on Centos 6?

I'm new on this; I really tried a lot before ask.. but nothing works. I did all that the qgis page says. Install ELGIS. after that i investigate and tried diferents comands.. but nothing works..the ...
6
votes
1answer
3k views

How to measure area correctly?

I have now used my entire evening, but I can't figure out how to make areal calculations (eg. in km2). I have tried the 'field calculator', I have tried the 'measure area' function on the "attributes" ...
21
votes
4answers
2k views

How to calculate terrain Curvature?

I have an elevation raster and I would like to get some basic terrain variables, such as slope, ruggedness, aspect or curvature. The problem is that I don't seem to have the possibility to calculate ...
3
votes
3answers
1k views

How to join Shapefile and Excel data without unique ID column?

I have one huge shapefile with lots of roads (polylines) along with various attributes and I have an Excel file containing some of these roads by three same attributes (road no., section no., length) ...
4
votes
1answer
93 views

Why are selected features not highlighted in OSM layers?

I am experienced with GIS, but new to QGIS and Opensource data. I recently opened an Open Street Map (osm) file in QGIS 1.8 (on Kubuntu 12.04). I found that when I selected a feature, there was no ...
2
votes
2answers
1k views

How to classify/style rasters correctly?

I am using a GeoTiff raster data and trying to classify it. I was wondering what are the techniques that I can use in QGIS to do this? The raster I have looks like but I tried the reclassify tool ...
1
vote
1answer
263 views

How to connect QGIS to an online database on Mac OS X? [closed]

I'm a real beginner/dummy when it comes to QGIS and online databases. I have tried a variety of things trying to connect to Spatialite, PostGIS and MySQL but all attempts have failed due to my lack of ...
5
votes
2answers
474 views

Setting up an online map site [duplicate]

Possible Duplicate: Steps to Start Web Mapping I have taken on setting up a database which stores information of an annual country-wide survey of alien aquatic weeds, linked to a GIS ...
1
vote
1answer
263 views

How can I import geometries from an invalid GML quickly?

I have the following gml geometry : <gml:Polygon xmlns:gml="http://www.opengis.net/gml" srsName="EPSG:2154"> <gml:exterior> <gml:LinearRing> <gml:posList ...
3
votes
2answers
736 views

How to use SAGA Kriging in Sextante for QGIS?

Hello, I tried to use SAGA (Ordinary Kriging) via SEXTANTE in QGis. The Sextante log tells me the following problem. Does anyone have a solution for my problem? By the way I'm usually a SAGA user but ...
2
votes
1answer
140 views

Qspatialite plugin problems with queries using inner join

I'm trying to create a layer in QGIS from a sqlite database using a query from 2 tables: one has spatial data and the other doesn't. When I build the query using Qspatialite using the 'Advance SQL ...
4
votes
2answers
680 views

GPS-Plugin and Garmin data

I am an avalanche specialist and I use a GPS Garmin 62 for fieldwork. I for example use waypoints to measure snow depth in avalanches for volume calculations. When I add a waypoint in the garmin ...
4
votes
2answers
325 views

How to iterate over selected layers?

In QGis by pressing shift or ctrl keys a user can select multiple layers in toc. How can a python script iterate over selected layers? I'd expect a iface.selectedLayers() but I can find only ...
6
votes
4answers
4k views

Qgis - Is there a way to split a polygon layer with a line layer?

I am drawing administrative regions that have boundaries follow streets in another layer. As these streets are pretty long with many vertices, I don't want to re-trace them. I am looking for a way to ...
4
votes
0answers
272 views

What to do about Geoserver WPS Warning “Could not get a ServiceInfo”?

This is the warning i am getting when i try to use this WPS service from QGIS, and the processing take a long time, but doesn't terminate, what might be the problem? 17 Oct 12:33:25 INFO ...
5
votes
2answers
1k views

Where can I get information on QGIS beta versions?

While searching for information on some qgis functionality on the web, i noticed several times, people using version 1.9, however this version is probably some beta (or so i thought) but i cant seem ...
0
votes
1answer
522 views

How to create a custom projection of PRS92 and UTM 51N for the Philippines? [duplicate]

Possible Duplicate: How to define new custom projections in QGIS? How do I create a customized CRS parameter in quantum GIS? I'm try to create a projection of PRS92 and UTM 51N. This ...
2
votes
1answer
280 views

Can I Dynamically Update Symbol Ranges?

Background: I'm currently trying to dynamically change the ranges for a layer with new style graduated symbology. Problem: I thought it may be as simple as updating the ranges for the existing ...