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

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1k views

Make a polygon from intersecting lines in QGIS, using Polygonize or similar?

In QGIS, I want to make polygons from a set of intersecting lines. Looking at the screenshot here, I want chop the purple line (it's a closed line, not a polygon) where it crosses the green and blue ...
2
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2answers
106 views

How can I get repeated vector grid in horizontal direction?

I need to get repeated vector grid layer in horizontally direction. I created many polygon vector grid layers, and their extents as listed bellow (Xmin-Ymin, Xmax-Ymax): Layer 1: 5910000 3040000 ...
2
votes
1answer
101 views

Obtain Longitude/Latitude Values and Export Data From QGIS

I have a CSV file with address data elements (Street# and Name, City, State, Zip). I'd like to be able obtain corresponding X,Y coordinate for each of the address? How do I achieve this using QGIS? ...
7
votes
2answers
622 views

How to split lines into equal segments with QGIS?

I'm attempting to split a curved (wiggle) line into equal length segments. Have used Grass's v.split which works to a degree but does not provide the output I'm after. v.split will extract segmented ...
1
vote
1answer
181 views

How can I style many layers of vector grid once in QGIS?

After I created many of vector grid layers, I now need to style them in a batch system. Is there any way to do this? If that is not possible, how can I use the layer duplicate option to inherit the ...
1
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2answers
77 views

How can I change vector grid extents in QGIS?

I created many vector grids, but later I discovered that I need to modify some of their extents, hence, How can I change vector grid's extents (xmin, xmax, ymin and ymax) in QGIS?
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2answers
46 views

Editting Attribute properties in QGIS

I am trying to edit the precision of my area attribute in QGIS 2.0. It is currently at 0 but I want to change it to 3. I have not been able to find the answer to this anywhere. Is there a way to edit ...
0
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1answer
336 views

Flow Mapping Lines by Magnitude

I am attempting to map the flow of remittances into Japan using the FlowMapper plugin in QGIS. When I use the Style--> Advanced--> Size Scale field--> magnitude command, the lines become so thick ...
1
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2answers
713 views

How to interpolate a point vector layer inside a boundary (polygon layer) QGIS/GRASS/SAGA?

I have a to create a heatmap of water temperatures inside a lake for which I have sample points. The map should look much like the climate maps generated by climate change models. I have the ...
0
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1answer
260 views

How can i clip vector layer in qgis and python?

I want to write a python function to create a shape file layer from clipping an input layer using a mask. Does someone know the way how to do it?
0
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1answer
31 views

Can't generate leaders with EasyCustomLabeling

I'm using EasyCustomLabeling with QGIS 2.0.1 and can't get it to generate the leader lines it is supposed to in Action 2. I create a new layer with EasyCustomLabeling, move labels to new locations, ...
1
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1answer
63 views

How to hide grid's labels when zooming out?

I have used polygon grid layer on my map, and I used to label the layer with ID automatically, and the result was convenient for me: But when I zoomed out, the labels didn't hide at all! and they ...
2
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0answers
234 views

How to add an offset to a GeoJSON layer in Leaflet?

Using the example GeoJSON tutorial code at leafletjs.com. Change the myLines variable so that the two lines overlap, but run in opposite directions as follows: var myLines = [{ "type": ...
3
votes
2answers
652 views

How do I define a bounding box within a WFS-request?

I need to get some data from via a WFS connection but due to the sheer size of the data, it takes for ever to load into Qgis or MapInfo. MapInfo has a feature which allows you to restrict the wfs ...
1
vote
1answer
131 views

no output file with grass:r.los

i'm using qgis 2.0 and i want to calculate a viewshed using r.los from grass tool box. after typing in the python console and a few seconds, i don't get an error message, but there is no file. the ...
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2answers
40 views

Fast location of items via attribute table in QGIS

Is there a way to quickly go straight to an item via the attribute table in QGIS 2.0.1? E.g similar to in ArcMap when you have the table open and double click the record and it zooms to it? I have a ...
2
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0answers
15 views

Eliminating/minimizing distortion in 200 NM EEZ buffers [duplicate]

I frequently need to calculate buffers of 200 nautical miles from country or baseline polygons in order to map maritime Exclusive Economic Zones (EEZs). However, I've noticed that when generating the ...
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0answers
31 views

Problems with other applications after installing QGIS 2.0.1

Since the official QGIS installation 2.0.1 (Virtual Server) various core applications from other departments in the municipality do not work always properly. Does anyone know the problem? Thank you ...
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0answers
33 views

Viewer Function

Is there a Viewer function/display in QGis as it is in ArcGIS. Or is there an other possibility to limit the access (just visualisation, no analysis). Thank you for your answer.
3
votes
3answers
514 views

Is there a way to hillshade vector polygons with a DEM in QGIS?

I have a layer of cadastral polygons that I'd like to display as hillshaded. For the elevation model I can use either an SRTM geotiff or use a set of 20m contour vectors. While I could make a jpeg ...
3
votes
1answer
176 views

how to snap two line vertex in two different layers used in QGIS

I want to snap between two poly-lines from 2 different layers (Layer1 in Brown and Layer 2(postGIS layer) in Pink color- ), but my snap option don't work. I have changed the tolerance to different ...
0
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1answer
132 views

Extract layer attributes and addresses QGIS

I have congressional district layer and a csv file with addresses. I'd like to extract all addresses and their corresponding congressional district. How do I do that using Qgis? The CSV File contains ...
5
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1answer
63 views

How do I contact the developer of a QGIS plugin?

I want to give feedback to the developer of a non-core QGIS plugin. (Numerical Vertex Edit by Cedric Moeri, who seems to have no webpage for his plugins) I joined OSGeo Wiki but hardly know my way ...
1
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1answer
51 views

How to randomly select from existing points within each polygon?

I have a polygon layer (where each feature has a class attribute), and a point layer, and there are at least 10 points within each feature of the polygon. Is there a way to randomly select only "k" ...
3
votes
1answer
128 views

Why does Save as “Rendered Image” change the raster styling?

Rasters exported from QGIS (via Save As > Rendered Image) do not retain original styling. See attached. Any thought on how to prevent this error? The top image is exported from QGIS as a .bmp, the ...
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0answers
600 views

Indoor mapping with floor plans and item(s) to track

Warning: GIS noob here. Essentially I want to be able to create a floor plan for a given room. Consider the following image of a floor plan in image format: I would have the measurements of every ...
2
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2answers
1k views

QGIS Get extent of layer

Is there a way to get the extent (bbox) of a vector layer in QGIS? I see that I can update the extent, but I am looking for the actually for coordinates of the extent.
2
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2answers
169 views

Minimum requirements (especially screen size) for QGIs - Android

I would like to try Qgis on Android devices, but before, I would like to know the minimum terminals requirements, and especially the screen size or resolution, what is the minimum screen size do you ...
0
votes
1answer
85 views

Analysing a network distance to two or more points using GRASS or QGIS

I am doing a piece of analysis work looking at distances along a network in GRASS. Most of the analysis involves finding which parts of the network are within 600m of a series of points. GRASS does ...
1
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2answers
71 views

View an .ecw-file in QGIS 1.8.0? [duplicate]

I have got a .ecw-file that I want to somehow import into QGIS 1.8.0. Is there a plugin that I can install that can help me do this or is there another way? The .ecw-file contains rasterdata.
0
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1answer
143 views

How do you install updates/patches for bug fixes in QGIS?

I'm trying to fix this bug in Qgis 2.0. I suppose the code, under the "Files Changed' tab needs to be copied/installed somewhere? Could you please advise on how to do so? I cannot find any help ...
2
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4answers
130 views

Best way to 'join' polygons

I'm looking for the best ways to 'group' a budge of block polygons in a new polygon that should be the town. My block layer is something like this: Or zoomed: And I'm looking to get something ...
2
votes
3answers
207 views

Imported GPX files into QGIS ver 2.0.1-fields missing?

Just imported GPX file into QGIS.Opened attribute table. where are the following fields? Latitude,Longitude,,symbol,and time . Am I missing something??I used a Garmin Oregon 300 to collect the data. ...
0
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1answer
66 views

attribute table in qgis wont save custom values

I am trying to edit a point shapefile in qgis and I have editing on for that layer, I have added a new column for the custom data, I have set it to text and have 8 characters allowed in the column ...
1
vote
1answer
155 views

How can I use Openflights database in QGIS?

I would like to have a shape file with the airports position and the routes of the planes I've found Openfilghts but I can't use it in QGIS. Seems that the format of the DB .dat is not supported by ...
0
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2answers
77 views

Show only some buildings

How do I show only some buildings? I only need to show 3 cabins in the forrest, but not every house in the whole village around, and the city close by. Maybe some of the symbol buildings in the city ...
3
votes
1answer
257 views

Show alternating contour lines

Is it possible to show only every other counture line? And how do you do that? (Im new to QGIS Lisboa 1.8.0, but even newer to QGIS Dufour 2.0.1, but have used ArcGIS a bit a while ago, and also ...
0
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1answer
38 views

How can i find shrines nearby location [closed]

How can i find shrines/complex/institute nearby location in qgis and highlight them. The below image is similar to my shape files which contains all information of all attributes,i don't know python, ...
1
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2answers
1k views

QGis 2.0.1 mapserver extension missing

I tried to export my Qgis projects to mapserver, using RT mapserver extension, because there is not any other extension in my version of QGis.(QGis 2.0.1 Dufour on ubuntu 12.04 LTS). After installing ...
3
votes
1answer
752 views

How to display an elevation profile and store the DEM elevation back to the KML line?

When I draw a track in Google Earth, for example along a road, I can right-click it to "Show elevation profile", and it displays a 2D plot of distance vs elevation. However, if I save the KML, the ...
1
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1answer
81 views

KML file saved from KMZ missing tabular data

I saved a KML file in Google Earth from this KMZ ... https://www.rampp-team.com/documents/pennsylvania/watershed/LowerSusquehanna/lancaster_pa/Lancaster_CSLF.zip . Upon opening the KML file in QGIS, ...
1
vote
1answer
218 views

Apply r.neighbours or Neighbourhood analysis (LecoS plugin for QGIS) to 3000 rasters

I need to apply r.neighbours or Neighbourhood analysis (QGIS plugin LecoS (or equivalent) to 3000 rasters and define a neighbourhood of 5 x 5 and calculate the mean. I suppose I need to create a ...
2
votes
1answer
350 views

Why do Print composer templates not save my maps in their entirety?

I have been using QGIS and its various updates in a limited way to make maps for a few years now, but I have always had the same problem with the Print Composer. I make my layered maps with grouped ...
6
votes
1answer
2k views

Syntax of conditional statements in QGIS Field Calculator(s)

I have a shapefile which I need to modify. There is one column "CLASS" with the attributes: "A", "B" and "C". I need to change "A" into "1!, "B" into "2" and "C" into "3". I tried it with case when ...
1
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0answers
52 views

How to sort SLD file for BGS Digimap provided by Edina?

Does anyone know how to sort the sld files provided here: http://digimap.edina.ac.uk/webhelp/geology/using_data_with_gis/legend_files.htm The reason I ask is that I only want to display the ...
2
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0answers
143 views

Where does QGS write its error log messages?

I want to read and copypaste the error log for the crashes I am experiencing in QGIS 2.0. The error I am getting freezes QGIS so I have to ctrl-alt-del. I can see the last mesasge in the panel, but ...
2
votes
1answer
143 views

Why are my symbols not displayed correctly in the legend and after a PDF-Export?

I work with QGIS 2.0.1. I have two problems with the representation of symbols. The first problem is that after I selected a symbol with the type: font and adjust the size of the symbol with the ...
1
vote
3answers
210 views

How ensure data put into PostGIS gets proper CRS attached?

I recently had an intractable problem that we finally traced back to the fact that some points in a PostGIS table had a CRS associated with them and others did not. This resulted in some points being ...
3
votes
3answers
81 views

How do I create a map that is not to scale in QGIS?

I want to make a map that isn't to scale and I'm so used to being pedantic about CRS and scale that I don't know where to start. The map that I need to make is a simple guide for people to get to a ...
5
votes
2answers
737 views

Rendering and Labeling Shapefile with PyQGIS

I've been running into a few problems working with the QGIS API for python. I've gotten more comfortable working in the python console in QGIS but I run into problems when I try to run the code ...