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

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1
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2answers
416 views

Qgis - need to draw exact lines (mtrs) with fixed angle

I use GIS 1.8. I have the need to be able to draw exact lines and shapes on a bing map. (This is to project a yet to be build greenhous project on a map to show what i would look like). I have ...
2
votes
3answers
3k views

QGis: Merge intersecting polygons into one which are part of the same feature

I'm not a GIS professional so I hope I use the correct wording, at least I hope you understand my question. Let's say there are 5 polygons in the feature A. In the shape file there are more ...
1
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1answer
83 views

How do I prevent QGIS 1.8.0 changing my dbf table values when joining tables?

Im a newbie on GIS as well as QGIS. I have a table of data saved from Excel as dbf format. After dragging and dropping the file into QGIS and then opening the attribute table, all values less than 1 ...
5
votes
4answers
733 views

ArcGis Trace Tool for QGis?

is there any tool in quantum gis that traces a line like the trace tool (Editor Toolbar) in arcgis? I want to draw a line and trace this line back so that i get the beginning and the end of the line ...
1
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0answers
23 views

Creating a buffer based on area (i.e. sqm) instead of distance [duplicate]

Is there a way in ArcGIS 10.1 or QGIS (or any add-on) to create buffer based on an area (i.e. sqm) rather than using buffer distance? I'd like to create a buffer of let's say 5% of the area within the ...
7
votes
1answer
214 views

Is Python essential for working in QGIS?

I am a beginner in QGIS. I Generally have a doubt: to work in QGIS is it necessary to know Python? whether i am asking we should know to write python programs to make certain modules run?
2
votes
1answer
628 views

Fetch Python Plugins missing

I'm running QGis master v1.9.0 on xubuntu and the 'fetch python plugins' option is absent. This guy had this problem with vanilla 1.7.5 but fixed it by upgrading to 1.9.0 master. Nishant had this ...
4
votes
4answers
1k views

How to get vector data from OSM to use in QGIS?

How do I get data from OpenStreetMap which I can then edit in QGIS layer by layer? What is the best OSM output and what / how do I get to a suitable input for QGIS? OR...is there another appraach to ...
1
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1answer
131 views

QGIS Layers Not Lining Up

I am new to QGIS, I have been using ArcGIS for most of my maps. I have two layers that are not overlapping properly. One is a shp file from a GIS clearinghouse and another from a delimited text ...
1
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0answers
95 views

Is it possible to undertake spatial clustering with QGIS?

Is it possible to undertake spatial clustering with QGIS, and also end up with proportional symbols in a quasi 3-d symbology?
0
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1answer
1k views

How to search text string and select item in QGIS?

I have a table attribute with complete roads name. I have to search items by digiting a part of the road name and I need to colour all the items selected. eg: ROAD NAME: / road 01 / road 02 / road 11 ...
0
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1answer
66 views

Using an image file as a placemark in qgis

I am making a map of sports clubs in London. I have each club's crest as image files (tiff) and want to make the placemark symbol using these images. I know it's possible to upload images in the SVG ...
2
votes
1answer
199 views

QGIS and ArcGIS on the same PC

I work for a small non profit conservation organization and we have a reasonably high turnover of people... so it stands to reason that some people don't want to change from a preferred program. this ...
1
vote
1answer
71 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
vote
1answer
116 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 ...
0
votes
1answer
386 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 ...
0
votes
1answer
138 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 ...
0
votes
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 ...
0
votes
1answer
96 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 ...
0
votes
1answer
586 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 ...
0
votes
1answer
80 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 ???
0
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0answers
103 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
votes
1answer
178 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
182 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
281 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
votes
2answers
288 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
501 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
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
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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
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1answer
135 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
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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
473 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
736 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
217 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
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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
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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 ...
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
596 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
131 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
508 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 ...