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

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2
votes
1answer
325 views

Why does Table Manager not work?

After installation of Quantum GIS I tried to use Table Manager Module, but I can't do it. Here is the message: Nem tudom betölteni a 'tablemanager' modult innen: ['C:/PROGRA~1/Quantum GIS ...
3
votes
1answer
412 views

Sum up area left “underneath” polygons in QGIS?

I have an area shape layer and multiple other area shape layers. Now I would like to calculate how much space (square kilometers or percentage of area) of the polygons of this area layer is NOT ...
3
votes
2answers
403 views

How to make QGIS recognize EPSG:31468?

I have Shapefiles without a CRS (e.g. without .prj file). I would like to set the CRS (EPSG:31468) before I pass the Shapefiles. I tried the following: Setting a .prj file manually with the string ...
4
votes
3answers
1k views

How to Clip a Vector File based on certain Raster Values?

I need to clip a vector file based on certain values of a raster (Slope > 2%). I can´t find a direct way to do it. Trying to vectorize the raster first didn´t work. Is there any tool (ArcGIS or ...
4
votes
3answers
653 views

Is there a “Tabulate Area” function in QGIS?

I have a raster file about land usage in northern italy (crops / urban areas ecc..) I have defined some buffer zones around some given points of a vector layer and I'd like to calculate the % of ...
5
votes
2answers
436 views

How to reset MacOS QGIS to defaults?

I can't find a way to clear away all imported QGIS styles, even completely removing all QGIS files, after new install - old styles are still there. Where to look? Removing one by one is the only ...
2
votes
1answer
2k views

QGis failed with error: latitude or longitude exceeded limits

I have some shapefiles from vegetationtypes in QGis and i wanted to put a googlemap in background, so i installed the open layers plug in. But every time i tried to load the map, theres an error ...
1
vote
2answers
535 views

How to install Sourcepole zonal statistics

I am trying to install the zonal statistics tool created/supplied by sourcepole from http://www.sourcepole.com/2010/12/16/zonal-statistics-plugin-for-qgis. The instructions area as follows: **To ...
2
votes
3answers
1k views

Qgis Python code library documenation.

I'm looking for python documentation for specific operations in the Qgis python console. I know there is no suggestions simular to Arcpy but I would like a pure list of operation code lines as ...
4
votes
2answers
965 views

How to make line width scale-dependent

Is there a way to tie line width to map scale in QGIS? All I found was an outside limit for display as the scale decreases. I'm using an outline line style for roads, and the roads are too big when ...
1
vote
2answers
1k views

How to calculate the average value of a raster within polygons?

I am using the GRASS plugin in QGIS. I am trying to calculate the average value of a raster dataset within a set of polygons. I have created a new mapset and have imported both the vector and ...
7
votes
4answers
6k views

How to calculate raster statistics for polygons?

how can I calculate sums, averages etc of raster-points (multi-band) per polygon of a vector-layer. I was told that this is called "zonal statistics". I tried that with QGIS first. There is a way to ...
1
vote
1answer
275 views

Is there any support for Rasterlite in the Android QGIS?

Is there any support for Rasterlite databases in the Android port of QGIS? I have tried adding a raster layer as I would on desktop QGIS but there are fewer GDAL file formats listed. Is this ...
3
votes
2answers
858 views

Generate non-overlapping shapes from a buffer

I have a collection of points, and I need to generate shapes around these points. Let's assume that these points are locations of offices and that the shapes are the 'area of responsibility' around ...
3
votes
1answer
186 views

How to create a point layer from a one-to-many join?

I have two layers: One with geographical coordinates containing every address in the county and a unique identifier. The second contains a list of incidents with the unique identifier from the ...
0
votes
1answer
441 views

shapefile and multiple lines of census data QGIS [duplicate]

Possible Duplicate: How to join multiple records to single feature? I am hoping to be able to link in the attribute table more than one line of data from a census entry per polygon. for ...
7
votes
1answer
487 views

What are the rules that the Gdal rasterize function follows to allocate a value to a cell?

How does the rasterize tool decide which value to represent when a cell covers an area which inclueds different values? I need it in this case for polygons but would like to know for lines and points ...
8
votes
0answers
682 views

How to define Winkel Tripel in proj 4.8.0?

I have QGIS with proj 4.8.0 installed. I'd like to add Winkel Tripel projection which seems to be defined as +proj=wintri But that definition string does not work. Is this a bug in my proj version, ...
1
vote
1answer
351 views

How to get a legend for a WMS layer and search in it?

How to bring legend and search for WMS layer in QGis? I can see the WMS layer in Qgis but can't make any legend for identifying feature types and searching in WMS layer?
2
votes
2answers
449 views

Which labelling tool/engine in QGIS will be supported in the long term?

Why does QGIS appear to have two labelling tools? (Note this is not new and old symbology, but that...) there are two different GUIs, one in the toolbar (which gives the Data Defined Settings option) ...
2
votes
3answers
1k views

How to search feature in Qgis?

How is it possible to search feature on Qgis? I have lots of points with Id. Is is possible to search points using ID? Update: I'm looking for a solution that centers the map to that point.
1
vote
0answers
650 views

SDA4PP not found? How to do Kriging in QGIS?

I need to make kriging analysis in QGIS (v1.7.4). I found out, that it should be a part of SDA4PP plugin, but I just couldn't find it in any repository (even third party). It looks, like it just ...
3
votes
2answers
416 views

How to get the layers of my project to show while tracking with GPS?

I've been using/testing several versions of various GIS software and run into occasional issues. Right now, my biggest with QGIS is with GPS connection/downloading from/tracking. These are all ...
1
vote
2answers
1k views

How to project TIGER & WGS84 to Spherical Mercator?

So I've been banging my head on this for about a week now. I'm using QGIS on a Mac. I have various shapefiles in WGS84 and Census TIGER NAD83 (EPSG:4269) and I would like to give them the same ...
2
votes
3answers
344 views

How to embed metadata into a spatialite layer in QGIS?

Example usage: I have a spatialite layer which contain my fiber optic cable routes. In that layer there is a column named 'Cable types' with coded integer data: 1 for aerial cable, 2 for underground ...
1
vote
2answers
3k views

How to visualize grd files in Quantum GIS?

How to visualize grd files in the software Quantum GIS?
3
votes
1answer
2k views

How to transform shp file into raster file in Quantum GIS?

I'd like to transform a shape file into raster file in Quantum GIS... and the opposite way back also (raster to shp). Can you help me?
3
votes
3answers
2k views

Are there any geocoding plugins for QGIS that interpolate along linear features instead of querying web services?

I am curious if there are any tools for QGIS to facilitate geocoding tabular data using a local linear features layer (ie, a street map with street name and address ranges - similar to geocoding in ...
2
votes
0answers
84 views

Does qgis-server support join?

I'm having troubles getting joins work with qgis-server. I'm not sure if it's a qgis-server problem or a qgis-web-client problem (bug report). Anyone has a working project using joins?
2
votes
2answers
418 views

Graduated Symbol classification not working with a decimal range

I am classifying an .adf wind resource map which I vectorised using the Polygonise tool (which worked very well). I have classified the data using the Graduated symbol renderer using Natural Breaks ...
2
votes
2answers
326 views

Is it possible to attain a classified raster with several classes in just one QGIS raster calculator operation?

I'm using qgis' raster calculator and wanted to make a new raster (oraster) from the values of an input raster (iraster). something like: if iraster>2 then oraster=1; if iraster >4 then oraster=2; ...
1
vote
0answers
244 views

Manifold 'Link drawing to query' - can I do this in QGIS?

Manifold GIS allows the creation of dynamic drawings linked to queries. Unfortunately I do not have access to Manifold as my employer refuses to pay for it, so am currently investigating ...
3
votes
1answer
489 views

Where to activate “Vector” Menu?

I am a QGIS newbie trying to work through Lex Berman's QGIS tutorial. I'm stuck in the "join" unit, because I do not see a Vector menu on my menu bar. The screen shots show that there should be a ...
2
votes
0answers
157 views

Are there Plugin Compatibility Issues between QGIS 1.6.0 and 1.7.4?

I've been working on a QGIS plugin on Quantum GIS 1.6.0 Copiapo with Python 2.5 that calculates additional values for eachf feature of a vector layer and adds them to the .dbf. We've just upgraded to ...
2
votes
1answer
156 views

How to digitize from a map with additional detail views?

I have a map with a river that includes islands within it. Some islands have a blown up version (detail views) outside of the river showing land ownership details. I would like to make polygons ...
6
votes
2answers
4k views

How to copy features from a vector layer to another vector layer with only correspondent attributes in QGIS

I have two vector layers: A first one with all cadastral parcels of a region. This layer has several attributes, it's only the geometry and 3 of the attributes I'm intrested in. My second layer is a ...
2
votes
1answer
570 views

How to show labels depending on the zoom scale and save it forever in one project?

I have got a problem in showing labels for a polygon layer : When I select "Show labels" in the layer's properties, then I select that I want to use the scaling to show or not my labels and I ...
1
vote
2answers
815 views

How to modifiy how selection highlights are displayed? [closed]

I have got a layer of points that are showed with a litlle symbol. When I select one, a red square comes around it. The problem is that this points are inside other layers (polygons) and some of them ...
4
votes
1answer
2k views

How to display places names when using Quantum GIS and shapefiles?

I am new to the world of geo systems. What I would like to do is displaying some information on a map for given regions. I downloaded shape files from cloud made web site and load layers using ...
4
votes
4answers
4k views

How to import qgis.core to python app?

I'm new to Python. I want to create GIS app with Python using QGIS library on Window 7 64bit. The way I do: install QGIS 1.7.0 I set PYTHONPATH=D:\Program Files (x86)\Quantum GIS ...
5
votes
1answer
135 views

How to keep Table Order in Identify Results?

Is there a way to keep the default table order when using the "Identify Feature" tool. I see that you can sort the "identify results" by table column name or value. I don't want the data in this view ...
3
votes
3answers
1k views

How to extract the US from a North America Shapefile?

I have a north america shapefile, downloaded from ftp://ftp.epa.gov/wed/ecoregions/cec_na/NA_CEC_Eco_Level2.zip How can I get a new shapefile from this showing only us? Is there a way doing this in ...
3
votes
3answers
855 views

How to add a raster legend with min/max values in QGIS 1.6?

I calculated/made NDVI with landsat data using ERDAS. Results of NDVI is in black and white map but I need it in colour to present the scale for NDVI with value of pixels in Map Composition. How to ...
1
vote
1answer
718 views

Why does qgis become unresponsive when adding a .sid raster layer?

Can someone provide insight into why qgis becomes unresponsive when i try to add a raster layer? Specifically a .sid raster from NAIP imagery. I can no longer add these raster layers to projects, even ...
2
votes
1answer
504 views

Why does intersect not calculate polygon areas?

this is strange: I intersected 2 shape-files and the resulting shape does not contain the Shape_Area and Shape_Length of the intersected polygons. Instead the field Shape_Area contains the ...
2
votes
2answers
747 views

How to control line width in legend in QGIS?

I have a map in which I am defining the sizes of various features in map units. When I come to generate a pdf of the map, using the Print Composer, the map itself is fine, but when I include a legend ...
0
votes
0answers
253 views

QGIS GDAL integration of new version [duplicate]

Somewhere else on this forum ("How to access file geodatabase in Qgis?") someone asked how to access data from an Esri file geodatabase in Quantum GIS? One of the answers pointed to ...
5
votes
0answers
613 views

How to get rpy2 for QGIS on OSX?

I am a new QGIS user, have installed QGIS on a Mac running Snow Leopard OSX 10.6.8 following all the instructions. QGIS seems to work well for everything other than when I boot up I get the message ...
3
votes
2answers
4k views

How to export a raster layer for external processing?

Is there a way to export all values from a raster to for example a cvs or other textfile or dbf or xls and later import (changed) values from that file back into the raster? For vector-files this is ...
2
votes
2answers
2k views

How to exclude missing values from raster layer?

In my raster layers the value -999 means "missing". Those points completely mess up any colormap in qgis because qgis treats them as normal values and includes them in the classification. I would ...