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

learn more… | top users | synonyms (1)

2
votes
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
votes
6answers
510 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 ...
1
vote
2answers
61 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 ...
1
vote
1answer
136 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
0
votes
2answers
132 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
votes
2answers
480 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 ...
3
votes
1answer
738 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
218 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
votes
0answers
240 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 ...
1
vote
0answers
66 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
votes
2answers
121 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 = ...
0
votes
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 ...
0
votes
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 ...
0
votes
0answers
256 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 ...
1
vote
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
vote
1answer
162 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 ...
1
vote
0answers
220 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 ...
1
vote
2answers
598 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* ...
0
votes
0answers
117 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
9k 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
votes
1answer
513 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
votes
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
239 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
122 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
votes
1answer
422 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 ...
1
vote
0answers
362 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
265 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 ...
0
votes
0answers
171 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
votes
0answers
759 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 ...
1
vote
0answers
308 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
votes
0answers
69 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
votes
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, ...
1
vote
1answer
290 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
votes
1answer
135 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
votes
0answers
203 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 ...
1
vote
2answers
180 views

How to modify the results of a geological dataset from vertical to horizontal?

I have a 3-D point shapefile of a geological fault dataset consisting of x,y, and z columns. I need to create a raster dataset from this point dataset. I have been trying to do this in ArcGIS; ...
-2
votes
2answers
499 views

QGIS 1.8 python refresh maps

i have developed this plugin .. all works fine but the map wont get refreshed . here is code vectorCount =0 mpointCount=0 mlineCount=0 mpolygonCount=0 mrasterCount=0 mlegnd = ...
0
votes
2answers
299 views

Where to find the variables of QgsPolygon and QgsPolyline?

now I want to use QgsPolygon (and Qgspolyline,too) class in python I have a example by using QgsPoint but I don't know how to use in QgsPolygon following is my Qgspoint example feature = ...
3
votes
0answers
320 views

When will QGIS version 2 be available? [closed]

Just wondering, how close is the public release of version 2? I do realise that I can download 1.9, but was wondering about the public version.
2
votes
1answer
89 views

How to split complex lines?

I want to edit some complex polylines, which I imported from my GPS. These polylines have many vertices and are selfintersecting many times. When I try to split these lines using the 'Split ...
1
vote
3answers
2k views

Saving of multipolygon shape file into a individual polygon shape files [closed]

How to seperate a multi polygon shape file into individual polygons(as seperate shape files)? i had huge data... I know the traditional process like export data... Please help me.. Thanks in Advance
1
vote
1answer
290 views

How to create a 4 band image from an RGB and a grey scale image?

I have an RGB image and a Gray scale image. I would like to merge them in a 4 bands image. How can I do that? Is there a simple way to do it from QGIS or I have to modify the image before to load them ...
1
vote
2answers
1k views

How to fix OpenLayers plugin for QGIS Master?

I can't get the OpenLayers plugin to work in QGIS Master (1.9), I loaded the repository successfully, but the plugin doesn't come up as an option anywhere. I'm new to this, but have tried to make ...
0
votes
0answers
125 views

QGIS 1.9 problem with setGrayBandName on the QgsRasterLayer

I have installed the developer version of QGIS on my computer in order to do some work with a multiband raster file. The file consists of 30 bands of information, and I need to step through it with a ...
0
votes
1answer
241 views

Why postgis st_overlaps reports Qgis' “avoid intersections” generated polygon as overlapping with others?

I am implementing a postgis trigger on polygon layer to check and reject newly created polygon if it overlaps others. The problem shows when I digitize new polygons adjacent to others in Quantum GIS ...
0
votes
1answer
163 views

How to symbolize features in QGIS?

Why is a shapefile shown as coloured independent features in ArcGIS shown in a single colour in Quantum GIS? What can I do to display this layer (wwf ecoregions) with the different ecoregions ...
1
vote
0answers
55 views

Why are the Raster z-value changed when reprojecting?

i have raster data with height values (z). when i try to reproject/warp the raster to gauss kruger 3, the z-values are changing (several meters). (the data is already gk3, but i have to reproject ...
4
votes
1answer
391 views

How can I create a new layer from the currrent selection?

Is it possible to create a duplicate layer, only displaying the selection from the layer you are duplicating in QuantumGIS? Simular to ArcGIS -> Create Layer from Selected Features. I looked at "How ...
1
vote
2answers
59 views

Discontinuous elevation contours at boundary of CanVec datasets

I am using Quantum GIS and I am working with the elevation contours from two adjacent CanVec datasets. The problem is that many of the contours' endpoints at the shared boundary do not coincide with ...