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

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QGis CadTools CAD Console

I need help with the Qgis CadTools CAD Console commands. According to these help files there are six commands. I just can't get them to work. Can someone help me? Thanks
3
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1answer
240 views

QGIS 1.8 does not launch

QGIS 1.8.0-1 does not launch (nor its companions: Browser, Grass, etc.) neither on machine with Win XP SP3 nor with Win 7 (GRASS installed separately works well). Console displays a message on launch: ...
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78 views

How to get the geometry of a polyline to a specific precision?

In python, I use point = geom.asPolyline() but it looks like I am not getting any precision just whole numbers? How can I get the geometry and a certain precision?
5
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1answer
775 views

Remove duplicate nodes in QGIS

I am trying to create a polygon feature from an enclosed line feature using the Geometry Tool: Lines to Polygons. When I do this, I get several spikes with the newly created polygon. I then run the ...
3
votes
1answer
140 views

How to use the QgsDiagramRendererV2?

I'm writing a plugin for QGIS in python in the QGIS API doc, I can see the QgsDiagramRendererV2 class, under the qgs.core section http://www.qgis.org/api/classQgsDiagramRendererV2.html What I'm ...
4
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3answers
670 views

Convert Ordnance Survey NTF data to QGIS compatible format

Is there a way of converting Ordnance Survey NTF data to QGIS that will correctly import the data and build polygons? QGIS will read the data as is, but it imports the polygons only as ...
2
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0answers
33 views

How can I set python path and version for QGIS? [duplicate]

Possible Duplicate: Couldn’t load SIP Module When I'm starting QGIS I'm getting the problem: "Couldn't load SIP module. Python support will be disabled." And there is also: Python version: ...
8
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1answer
368 views

How to split two interscting polygons by the average linestring of the shared area (QGIS / python shapely)

I have two polygons, POLYGON((-5 -5,-5 5,5 5,5 -5,-5 -5)) POLYGON((1 1, 1 7, 7 7, 7 1, 1 1)) and wish to split them evenly. The result should be a split along the red marked line. I'm using ...
2
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0answers
235 views

Postgresql Query Plugins Not Returning Results in QGIS

I'm using the Fishnet function as described here to create a grid. If I use the following SQL to call the function to position a grid where I want it (I'm using NZGD2000 SRID = 2193) the query ...
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1answer
135 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
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1answer
2k 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
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216 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
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1answer
948 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
41 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
372 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 ...
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1answer
181 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
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0answers
317 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 ...
3
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2answers
609 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
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1answer
461 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
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3answers
751 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
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1answer
210 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
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1answer
721 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 ...
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0answers
99 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 ...
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3answers
933 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
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2answers
949 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
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1answer
118 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
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2answers
270 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
84 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
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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
165 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
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1answer
7k 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
397 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
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3answers
159 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.
10
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3answers
4k views

How to do hydrological modeling in QGIS?

Can someone please direct me to a tutorial where I can learn more about hydrological modelling? I am particularly interested in learning how to model flooding using data from gauging stations along ...
2
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1answer
186 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
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2answers
826 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
310 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
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0answers
161 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
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3answers
869 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
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3answers
504 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
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0answers
337 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
2k 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
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1answer
2k 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
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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
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1answer
89 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 ...
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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 ...
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1answer
217 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
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2answers
412 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 ...
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1answer
249 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 ...