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

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1answer
73 views

Get the ID of polygon in edition sessions of QGIS?

I did a Qt custom form for QGIS which contain a QlineEdit that must get the ID of the current polygon in edit session. For example, I start edit sessions I draw 3 polygons when the Qt form is opened ...
1
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1answer
118 views

How to write a expression in field calculator for finding $X and $Y?

I'm trying to calculate the lat/long of points using the Q GIS field calculator.Nathan W suggested to First, save the layer as WGS84 and import it again. Then in the field calculator you can use $x or ...
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1answer
406 views

How to resolve error “Handle bad layers” in QGIS?

I'm new to QGIS and have been seeing what it can do for me – seems good. I imported shape file data from a UK Ordnance Survey data file and saved the file in a new folder. It was very good, doing all ...
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1answer
140 views

Installing raster resampling module in QGIS 1.8

On the website of Sourcepole, I have recently come across the case of resampling images in Quantum GIS. Because I am rather a beginner in GIS software I would like to ask you for information about how ...
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1answer
75 views

Table calculation in QGis

I have a shape file with the attribute "yield". I need to know the math difference between yield (id1) and yield (id2)...then yield (id2) and yield (id3) and so on... I hope you understand what I ...
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1answer
105 views

Why is the CSVT file changing my real values to null?

I made a CSVT file to change desired real data to string data. After importing the original CSV file, that was linked by file name to the CSVT file, the string data appears as normal however all the ...
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1answer
616 views

Can I export QGIS basemaps as raster in ArcGIS 10.0?

I'm mapping a National Park in Malawi using Quantum GIS as with the plugin I can get the images from G.Earth (I need to see the vegetation). Since my supervisor is using ArcGIS 10, do you know if ...
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1answer
82 views

How can i detect the number of polygon is drawed in a edit session in QGIS

I am working with qgis 1.8 and i want to know how many polygon drawed in one edit sessions is there any signal emitted with qgis ???
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0answers
109 views

Action: open file from database

I have an image stored in a db (postgres / bytea). Is it possible to display (open) this image with a qgis action? In Qgis I have a (postgis) layer open, one attribute is the id of the image in the ...
0
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1answer
181 views

How to draw a custom map on top of base layer

I'm looking for the easiest way to draw a custom layer and export it as a tile cache. Basically what I would like to be able to do is load a base layer, and then draw objects and annotations on top ...
3
votes
1answer
199 views

Creating a radius of influence around points

I have a vector file of points. What I need to do is create a circle with a radius of 12km round each point. Would it be possible to then find out what percentage of my total map is covered with ...
2
votes
2answers
301 views

How can I create a multipoint geometry in QGIS?

I've got a Spatialite layer in QGIS with geometry type MULTIPOINT. Now I'd like to add some data in this table in the 'usual' way, so by doing multiple clicks in the map (e.g. left-click, left-click, ...
3
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2answers
306 views

How can I turn islands into individual features in QGIS?

I have what seems like a pretty straightforward task in QGIS: I have a shapefile that, in some cases, groups multiple separate landmasses into a single feature. For example, the Hawaiian islands are ...
2
votes
2answers
544 views

How do I prevent Qgis from being detected as “not responding” when running a heavy plugin?

I use the folowing line to inform the user about the status: iface.mainWindow().statusBar().showMessage("Status:" + str(i)) The plugin takes about 2 min to run on my data set but windows detects ...
2
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1answer
148 views

Why is this line split in two?

Even though this is a single line, it is stored as a two-part polyline. I can split it and rejoin at the break, but whatever I do it won't join the two into one line. (This is most obvious if you turn ...
6
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6answers
527 views

Tool/Algorithm for generalizing OSM-Files for printing maps

Is there a tool or algorithm to (topological) generalizes OSM-shapes? I would like to build a printable map in different scales. In the image below you can see the same divided road (yellow) at ...
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2answers
62 views

Find the majority area within another area

I have a survey grid overlaid unto several administrative areas. Both are polygon features and I have performed a union on both features in order to determine the areal contribution of the segments ...
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1answer
139 views

What does “Computed -srcwin falls outside raster size” mean when clipping?

What does this mean, when I try to clip and save the result as a sqlite or other format please? "Computed -srcwin falls outside raster size of 7807x4771" cheers, Bruce
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2answers
134 views

Can Vector grid shape file be clipped with Satellite image in qgis?

I am working in open layers plugin in Qgis . in order to project the satellite image wit respect to vector shape file i am having, Andre Joost suggested me to create a vector grid with crs sysytem of ...
4
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2answers
505 views

How to draw lines from two points in a CSV?

I have a CSV file where one line looks like this: Duration, user, lat-start, long-start, lat-end, long-end 298, Casual,38.9101,-77.0444,38.91554,-77.03818 Each row in the CSV has two points and I ...
2
votes
1answer
786 views

Why does QGIS hang when I try to create a vector grid?

I am working in open layers plugin.i need to project the satellite data with respect to vector data shape file i am having .for that Andre Joost suggested to create vector grid with vector data ...
2
votes
1answer
237 views

How to update data from external table in real time?

I have been trying for a long time to connect a external table data[csv] through Excel (for exmaple) with QGis with the objective to each time i change any data in table(for example data location - ...
2
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0answers
245 views

How to create a dynamic, interactive map with QGIS?

How can we create an interactive map with QGIS? I would keep it in the bottom of aerial photographs. When the mouse moves over elements of a layer, I wish they will be highlighted and a window shows ...
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0answers
67 views

gpx conversion tools in qgis keeps asking for GPSBabel

I want to perform a simple task: show the waypoints of a GPX "track" as dots, not as a set of connected lines in QGIS ( Conversion -> Waypoints from a track ). I use files, not any particular USB ...
2
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2answers
133 views

Why does QgsSpatialIndex::nearestNeighbor(point, 1) sometimes return 2 lines?

I'm trying to get the closest line to a point using pyQgis in a plugin. The active code file is this: http://pastebin.com/TDzmsKVM When I request the closest line (only 1) nearestIds = ...
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0answers
18 views

Import attribute data? [duplicate]

I have a question that probably has a simple answer but I have not found it yet. Can anyone help? I have a shapefile of Germany's counties ("Landkreise"). Now I would like to add several attributes ...
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0answers
18 views

No fetch Python plugins in qgis 1.8 + ubuntu 13.04 [duplicate]

I tried to install qgis 1.8 to ubuntu 13.04 but when installation finished I couldn't find "Fetch python plugin" button in plugin menu. I didn't find any soloution for this problem. Any idea what's ...
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0answers
278 views

How to fill in the parameters for kernel density estimation?

I am desperately trying to calculate animals home range with kernel. Unfortunately, the result is obviously incorrect and I cannot identify my mistake (I would like to post a screenshot but its not ...
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1answer
73 views

Why is my custom QGIS repository not working in recent qgis-dev version?

I have a custom QGIS repository that worked well with my own plugins.xml on a private server. Yesterday I downloaded and installed the newest QGIS-DEV that now include some changes in the Python ...
1
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1answer
165 views

Failed connection with .sqlite file in QGIS converted from osm by spatialite

I have converted a *.osm file to a *.sqlite file using the spatialite_tool i.e sspatialite_osm_map.. Now I want to view the map using QGIS. However, at the time of using the add spatialite table ...
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0answers
224 views

How to load the default layer style from Postgresql with Python?

I would like to write a python macro that upon opening my QGIS project file will reload the default style for each layer from the postgres 'layer_style' table. I have had a look at the documentation ...
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2answers
633 views

How to draw a Circle of fixed radius in QGIS using QgsMapCanvasItem?

I have derived a class from QgsMapCanvasItem for drawing circle of some radius at a given latitude and longitude. In my paint function I am using QPainter to draw the circle as void paint (QPainter* ...
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0answers
119 views

Specify formatting of floating point numbers in QGIS labels?

Is there a way to specify the format used with floating point numbers used as labels in QGIS? By default they print with a large number of digits after the decimal place but I would like to specify ...
3
votes
3answers
10k views

How to convert x y coordinates to longitude latitude using QuantumGIS?

I'm working with this downloadable shapefile that has X Y coordinates. They are akin to '3672187.92698000, 534175.72095400'. I would like to convert them to longitude latitude so they are more like ...
2
votes
1answer
132 views

QGIS link values longer than the links?

Can you please help me to correct link rapresentation when the thickness exceed the links. In the image you can see the value on two consecutive links that generate a bad view. I think it depends on ...
2
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1answer
544 views

Can one convert text annotations to a layer in Qgis?

I know text annotations can be turned on & off with Ctrl+T... but is there any way to export them as a layer? Thanks!
4
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1answer
1k views

Is it possible to use DotNet to show a QGIS map?

Has anybody ever tried to show and interact with a QGIS map from a DotNet language like C#? What i have in mind is, to write a desktop application with C#, and show an embedded map with the QGIS-API ...
3
votes
1answer
245 views

QGIS: plotting real time lat/lon GPS input on a different projection

I'm trying to plot realtime GPS over a satellite image in QGIS 1.8. The GPS data is coming in as NMEA lat/lon from a Garmin Etrex. This works when the image is in WGS84 lat/lon projection and ...
4
votes
1answer
126 views

How to avoid cutting labels along the map border?

I am labeling areas on a map (for example, forest (coniferous, deciduous trees), swampland, and so on). A cartographer has criticized it because labels which extend beyond the boundaries of the ...
0
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1answer
441 views

Reverse geocoding polygon co-ordinates?

I have a large dataset of polygons for property sections that I need to reverse geocode. It was recommended that I use a GIS like Quantam to do this however from my research I am not 100% sure if a ...
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0answers
373 views

calculating home ranges with QGIS [closed]

i am facing some problems when trying to calculate animals home ranges with QGIS 1.8.0. One the one hand, when trying to calculate MCP with the Home range plugin, i get error messages. on the other ...
2
votes
1answer
283 views

Orthophoto in QGIS to georeference for use in Sketchup 8, or how to match it with Sketchup 8 pictures?

I have a high resolution orthophoto of an area I want to rebuild in sketchup and therefore want to lign it up (georeference it properly), but all the scaling and everything I tried so far did not help ...
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0answers
174 views

problems with r.sun from GRASS

I´ve problems with r.sun from GRASS. I need to calculate beam radiation, reflect radiation and diffuse radiation wwith this tool. my problem is I do not understand that you have to put mandatory files ...
0
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0answers
780 views

Add x y data from existing attribute table

In Quantum GIS, I already imported an excel or dbf table. Now I need to tell Quantum GIS which columns are Latitude and Longitude. How do I do that? I know there is Add Delimited Text Layer which ...
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0answers
310 views

Install shapely for QGIS on Mac

I know there are a number of similar questions, but none of them have answers that allow me to use shapely in QGIS. In particular I am trying to install the Contour plugin, but this fails with the ...
2
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0answers
70 views

How to run an external program on “identify” on a WMS layer?

I have a QuantumGIS project with several WMS layers. When I select one of these, the identify-function shows a windows with more information on the feature I clicked. It gets this data from the ...
2
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2answers
2k views

How to open an ArcGIS Desktop .lpk file using QGIS on a Mac?

I downloaded an LPK file from the ESRI site that contains USPS defined zip codes. Because I'm working with QGIS on a Mac, I converted the file to a .zip. There's a .lyr file that opened up in the zip, ...
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1answer
295 views

What do I need to do to add a new QGIS project to qgis-web-client?

for weeks I'm trying to get QGIS Server with qgis-web-client to work but I'm totally stuck. System is Debian Squeeze. In principle, I get QGIS Server and the qgis-web-client up and running: it's ...
0
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1answer
140 views

qgis field calculator - changing datatype

I have seen a solution that I don't get to work - I need to change data type from string to integer and I did what is shown i the image below Can someone point out what I do wrong? thx Jan
3
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0answers
213 views

Multiple text formats in a qgis label

Is there any way to have multiple text formats in a single qgis label? I am making a map that shows mountain summits. Many of these summits have more than one name and I would like to show each name ...