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

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2
votes
1answer
121 views

How to control road labels in Atlas QGIS 2.0?

I'm producing map books for our water assets. These books are taken out into the field by the workers so they can see where various 'things' are for the work they need to undertake. There are over 200 ...
1
vote
2answers
733 views

Calculate area covered by a particular raster layer within polygons in QGIS

I am trying to extract information on vegetation cover within a set radius of point locations (my sites). I have succeeded in creating a new vector layer of circles with a 5 km radius around my sites. ...
1
vote
2answers
93 views

How to convert small overlaping polygon features to inner ring in QGIS

I have a polygon vector layer with overlapping features (like below) and I would like to convert the features that are fully contained inside the bigger polygons (ie feature 2 and 4 below) into inner ...
3
votes
1answer
443 views

Upgrade QGIS from 1.8 Lisboa to 2.0?

I have QGIS 1.8 and I want to upgrade to 2.0 Dufour... Should I just download the file and launch the installation? Or first uninstall 1.8? Thank you! Lily
0
votes
1answer
125 views

How to create shapefiles with z coordinate with QGIS

I'm working with QGIS, and I want to create a shapefile with the elevation coordinate, I can't find something similar to what I was used to do in Arcgis, can you help me? Thanks for your help Luís
4
votes
1answer
541 views

Adding Multiple Maps in QGIS Composer?

I am working with QGIS Composer 2.0 and I would like to add a second map. What I would like to do is to have a main map that takes up the majority of the print area. This map, Main Map, will have ...
0
votes
0answers
153 views

how do I add attribute features to an attribute table which already exists?

Using Verson 2.0, downloaded as normal. I have an ESRI shapefile of my road map for 2006. I have a paper map of roads for 1969. I want to see what roads have been built between 1969 and 2006 (none ...
1
vote
1answer
476 views

Arc ASCII Grid output problem in QGIS 2.0

I used to convert tif files to ascii in Qgis 1.8 using gdal translate without having any problems with the output i.e. I have the normal heading and values. When I upgraded to 2.0 I started to get the ...
0
votes
2answers
424 views

Developing standalone gis applications using pyqgis

I am trying to develop a standalone application using pyqgis but I have no clue on where to start and where to write the code to make it happen so if anyone can provide me a tutorial to getting ...
0
votes
1answer
211 views

Problems with Polygon Reshape Feature

I'm new in this forum, and i need some help with my project. I've created a polygon and closed my project, after opening the project again, i can't use the Reshape Feature tool in that specific ...
1
vote
2answers
348 views

On the fly transformation From WGS84 to NAD27 with proj4 code

I want to use this proj4 code: +proj=utm +zone=19 +ellps=WGS84 +toclrk66=-3,142,183,0,0,0,0 +units=m +no_defs or this one +proj=utm +zone=19 +ellps=WGS84 +tonad27=-3,142,183,0,0,0,0 +units=m +no_defs ...
2
votes
3answers
619 views

How to remove vertices or lines within a polygon?

I have transformed a *.dxf-file into a polygon shape-file. In many of the polygons i have lines whicht do not belong there but i can not delete them as i normally delete vertices on polygons by ...
3
votes
0answers
101 views

Creating a new raster based on pixel value of original raster using raster calculator but new layer is not evident

I am trying to create a new raster based on a current raster (w001001 - NVIS) which has one paletted band, with palette values ranging from 1 to 29, with each palette/value representing a vegetation ...
1
vote
2answers
437 views

TIFF/Raster to Point shapefile question

Apologies in advance if this question is incredibly basic, but I've been googling around and I just don't know where to start. I've downloaded some nighttime luminosity data from NASA, and the data ...
1
vote
3answers
181 views

trouble installing the qgis2kml plugin (or, how to install plugins not available in the Plugin Manager from source)

I'm trying to install the qgis2kml plugin for qgis. Its not showing up in the Plugin Manager search and the only qgis "repositories" I can find are websites for downloading source code. Which is ...
3
votes
1answer
137 views

Tornado Data Points: Linking 2 Points in QGIS on the Same Row

So I've got these tornado .csv files that have two latitude & longitude entries with the left-most in the table being the beginning point and the right-most being the ending point of the tornado, ...
0
votes
1answer
94 views

How can i stop rendering Qgis

In my python plugin ,i select features from a vector layer dynamically using a loop and executing : VectorLayer.select(feature.id()) when i start the loop, the selection become very slow because ...
4
votes
1answer
239 views

Debugging errors of SAGA interpolation algorithms in QGIS 2.0 Processing

I encounter recurrent problems with the geoalgorithms that perform interpolations. No matter technique I use I end with the following errors. As state in OGR tab QGIS is unable to open a file in C ...
2
votes
2answers
61 views

Join by location on Qgis when target layer has multiple layer

I posted here a while ago about spatial joins. I have a huge dataset (20,000?) of bird and mammal ranges. I have another dataset of all the countries. In qgis, I was attempting to link the two ...
2
votes
2answers
65 views

How can I display a spatialLite view in a custom data sheet with print composer

I created a spatiaLite Database with a point layer (every point is a tree). Additional I created several tables to fill the columns of the spatial layer with attributes using the editing widget “value ...
2
votes
1answer
227 views

How do I access QGIS program settings programmatically?

I am trying to temporarily enable the option in QGIS using PyQt4 to suppress the attribute dialog popup after a feature is added. I found an example in the cookbook but it doesn't indicate how to get ...
2
votes
2answers
1k views

How to cut a line feature in QGIS 2.0?

I want to shorten a feature (a polyline representing a road) in QGIS 2.0. I tried the 'cut features'-tool that look like a pair of scissors. First I chose the right layer, and then clicked 'Toggle'. ...
1
vote
0answers
227 views

Display plugin icon

I'm unable to setup the display of the toolbar icon for a plugin in QGIS 2.0. I have compiled the "resources.qrc" with the correct path and filename, and checked possible spelling errors in the code. ...
1
vote
1answer
434 views

Creating a custom attribute table in qgis print composer

is it possible to arrange header and content of an inserted attribute table in qgis print composer? I want to create a custom datasheet with a small map and listed feature information as follows: I ...
1
vote
1answer
558 views

How to apply svg symbols as point markers in QGIS 2.0

I must be overlooking something obvious! I've just downloaded and launched QGIS 2.0. I'm trying to edit a layer's symbol markers to use a more descriptive icon. Opening layer properties and then ...
3
votes
1answer
1k views

how to fix greyed out edit button

I created a QGIS map, which I was able to edit (right click on layer and select toggle edit, or use button in tool bar). Having returned to work on the plan, most layers now have this button greyed ...
2
votes
1answer
154 views

What prevents GRASS and SAGA integration into QGIS when users aren't administrators?

Windows version of QGIS 2.0 using the stand alone installer. I have been able to tie up the functionality using the Options and Configurations settings in the Processing menu. This works fine in a ...
0
votes
0answers
82 views

QGIS 2.0 Performance issue when selecting by location on a complex dataset

I have an issue when I use the select by location tool in QGIS 2.0 to select points within a very complex polygon. It is flood data, so has something like 350,000 nodes and is generated as a single ...
0
votes
1answer
68 views

Dissolving polygons closers than 50m into a single shape QGIS

I’m new with GIS (coming from a CAD background) and using QGIS 2.0.1. I have a very detailed map of urban fabric in a UK region, to the detail of individual buildings. I want to simplify that map by ...
1
vote
2answers
578 views

Alternative repository for QGIS 2.0 plugins

Is there any alternative to the official repository for plugins of Qgis 2.0. I prefer to be a tested and trusted. EDIT: I found a source which refers to OpenGeo Explorer For more info: ...
4
votes
1answer
295 views

lookup forms in QGIS

Bit of an open question but.... Is it possible to design a form in qt designer that will be used as a form against a qgis layer but interacts with a different table in postgres/postgis as a lookup ...
0
votes
1answer
98 views

error in overlapping layers in QGIS

I created two tables with PostGIS, within which I have inserted a shapefile of an Italian region (Apulia) in the first, and the coordinates in the second table. In both tables are set with the ...
0
votes
0answers
97 views

Point features disappear when moved using QGIS 2.0

When I move, either by the node or the move function, a feature symbol on the map canvas, it simply disappears, not just the label, the whole thing. CTRL-Z brings it back. I'm using a MAC OS-X. I've ...
2
votes
4answers
626 views

Merge large number of polygons using QGIS

I have a series of polygons that are the output of another GIS program - I need to merge the polygons into a single polygon. I have tried a couple of different methods with no luck. I have tried to ...
5
votes
2answers
710 views

How to define leaders to a label in QGIS 2

In QGIS 1.8 and 1.9 I used a plugin called Easy Labels to develop leader lines that would be saved as a memory layer. I have not been able to replicate this with QGIS 2.0, I cant even find the Easy ...
3
votes
3answers
456 views

How to calculate peaks in a DEM

How could I extract all peaks from a DEM (large mountainous area)? Peak means something like: a pixel which is sourrounded by other pixels with smaler elevation numbers in a area arround the ...
5
votes
3answers
409 views

How to visually sort the order of Points with QGIS, GDAL, …?

The following Points layer is the basis of a rendering in a Android application. Android allows to draw a shape from the provided points. I cannot use LineStrings. However, the order of points ...
2
votes
1answer
187 views

How to show in a custom QGIS form the feature and/or geometry info?

I need to show point coordinates on the from dialog used to edit the attributes of a point.. I see that in the formOpen the dialog receives a layerId and a featureId, but no iface object, so how can ...
6
votes
3answers
269 views

How to find out if OpenStreetMaps contains low emission zones?

Since I never really digged into the data contained in OpenStreetMap I ask myself what would be the recommended way to identify layers or tags within the overall data. In my current use case I want to ...
1
vote
1answer
224 views

Is it possible to load automatically a customization file in qgis?

I have customized QGIS menu and toolbars thanks to the customization option and I have created a configuration.ini file that I can load on several machines. Now, is it possible to create a project ...
2
votes
1answer
599 views

QGIS OS grid overlay

I'm totally new to GIS. However, I've proudly managed to create a map, which is correctly geo-referenced with a Great Britain Ordnance Survey (OS) background (streetview level) and I've added some ...
6
votes
1answer
756 views

How do I convert a .dxf to a .shp containing a field with height information in QGIS?

I received two .dxf for my project that represent my area of interest. One of them contains buildings, the other one terrain elevation. They both are 3D. I can convert them to shapefiles successfully ...
1
vote
2answers
1k views

How can I replace all null values from attribute table to zeros?

I have a new column in my attribute table with a lot of null values and I want to replace all them to zeros. How can I do that in calculator? I'm using QGis 1.8 Thank you!
1
vote
1answer
78 views

Mismatch in area calculation using Field Calculator vs Group Stats in QGIS 2.0

I have two polygon files (A being my area of interest and B being a categorised land cover layer). Both layers were in the same projection (projected and not geographic). Using QGIS 2.0, I used the ...
0
votes
0answers
90 views

QGIS and raster calculator - not working

I have installed QGIS 1.8 on a Mac OS v10.8.4 (with GDAL and installed), and trying to create an NDVI map from a three-band GeoTIFF multispectral image. Even the simplest calculation (e.g. band@1*1) ...
2
votes
3answers
114 views

How to highlight polygons within another polygon?

I want to symbolize public buildings in OSM data. For Example: There is a polygon and in column "amenity" it has the value "school". But i don't want to highlight this polygon, but the buildings ...
2
votes
0answers
272 views

QGIS, “Handle bad layers” and empty layers

I'm a novice in GIS, so forgive me all possible mistakes I might have here... I'm using QGIS 2.0.1. (Dufour) with Mac OS X (10.6.8). I have couple of dozens(?) of vector layers added on a project. ...
2
votes
1answer
102 views

Irrational feature ID behavior in a PyQgis script

I've written a script to determine the coordinates of a point shapefile and insert them into its attribute table. It works perfectly when the ID sequence of the indiviual features begins with 0, yet ...
1
vote
0answers
96 views

How to load a SVG-File from QRC

I have a vectorlayer and want to give the points a svg-symbol. If I give the constructor an absolute path to my svg-file it works fine. Then i put the svg to my ressource file (qrc) and try to load it ...
2
votes
0answers
275 views

QGIS 2.0.1 connecting to ESRI WMTS jpeg vs jpg

I'm currently trying to troubleshoot an issue I have connecting to ESRI WMTS services. Esri ArcGIS Server seems to provide the format as JPEG via the rest service, but in the get capabilites ...