Questions tagged [qgis]

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

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6
votes
3answers
13k views

Saving project with data source path as relative in QGIS?

Is there an option in QGIS to save the project with the data source being a relative path? I don't see the option here. QGIS Wroclaw1.7.3
2
votes
2answers
3k views

Can two polygon layers be merged in QGIS on a common id?

Can two polygon layers be merged in QGIS on the basis of a common id? Update: Ok , the dissolve tool works fine. But for instance lets say I have 10 polygons. 8 of them are together , so when ...
4
votes
2answers
13k views

What are the units of the Distance Matrix tool results in QGIS?

I have a point data set. Now there are cluster of points based on a field. So I take out one such cluster which has points with same field.I want to find distance between all the points in cluster and ...
13
votes
0answers
7k views

Is it possible to export geospatial PDF from QGIS via GDAL/OGR? [duplicate]

Is there any plugin for QGIS which would help me in exporting the map document as a geospatial PDF (similar to Terrago's GeoPDF)?
8
votes
2answers
3k views

How to animate raster time series using open-source GIS?

I have a bunch of rasters taken about 10 minutes apart, and I have a nice QGIS project that produces pretty enough maps of them. I'm wondering if there's a way to animate this raster series, with a ...
39
votes
5answers
16k views

Calculating average width of polygon? [closed]

I'm interested in examining the average width of a polygon that represents the road surface. I also have the road centerline as a vector (which is sometimes not exactly in the center). In this example,...
1
vote
2answers
2k views

How to get the altitude of the vector shapes from DTM raster layer?

I have a vector layer containing thousands of vector shapes/polygons and a raster layer with DTM. Every shape has its own OBJECTID in attribute table. I would like to get the altitude of every shape, ...
7
votes
1answer
1k views

Displaying intersecting roads and creating multiple labels for long roads in QGIS? [closed]

I am new to GIS and I am using QGIS 1.7.3 on Windows. Can any one tell me how to display a map from line shapefile with these two characteristics: Roads are displayed with borders at the sides and ...
4
votes
2answers
7k views

Is there an option to remove duplicate polygon labels in QGIS?

I would like to know if there is an option in QGIS labeling engine which would remove all the duplicate labels. My polygon layer contains a few features with same name. So when labeled it becomes a ...
7
votes
2answers
1k views

How to create zip code areas from point data?

I have a point dataset which has zipcodes for a certain region. This zipcodes have been marked on the basis of lat long collected. So each zipcode is repeated as it would be useful to show the region ...
132
votes
4answers
282k views

Adding Basemaps from Google or Bing in QGIS?

ArcGIS Desktop has the option of using basemaps from ArcGIS online. Does QGIS have any such options?
1
vote
4answers
465 views

How to work with NREL data in QGIS?

I would like to use QGIS to display solar data from NREL. The file is supposed to provide solar radiation data of Colorado. However, I have some trouble to select this data in QGIS: In QGIS, I select ...
0
votes
2answers
1k views

How to remove overlapping buffer in QGIS?

I wanna know how to do this in QGIS: I've tried many ways, but still can't find the right solution.
7
votes
1answer
2k views

Why does QGIS's Clipper tell me “Computed -srcwin falls outside raster size” and how do I address it?

I'm trying to clip a heightmap to a small area that I'm interested in. When I attempt to use Raster > Extraction > Clipper I get an error dialog with the message ""Computed -srcwin falls outside ...
3
votes
1answer
1k views

Using QGis for an imaginary plane world

I created an own map for my p&p rpg group and now I want to transfer it into QGis. That's easy to make, but I'd like to have an own CRS for that map but don't know how to use the right proj.4 ...
1
vote
1answer
1k views

How to use MSYS with QGIS?

I found a very nice tutorial at: http://sproke.blogspot.com/2012/02/mapping-software-for-84.html, which has some "unix-like scripts", which should be use with QGIS. How can I copy and paste these ...
1
vote
1answer
399 views

Highlighting and exporting raster layer based on vector polygon

I am a Quantum GIS beginner. I have a set of adjacent polygons in a vector layer that is overlaid on a raster layer of OS StreetView OpenData. I want to be able to select each of these polygons and ...
3
votes
1answer
103 views

How to determine if feature A and B are located in the same room?

I have created a map using MapWindows like the following: A little explanation here, the is a map of an elderly home. The yellow boxes are room and the white rectangles inside the yellow boxes are ...
9
votes
2answers
545 views

What version of SVG should I be saving my images with for QGIS? Any particular options I should use/avoid?

I have a illustration in Adobe Illustrator that I'm trying to export as an SVG file and add to my map layout using the Print Composer of QGIS 1.7.3. When I add the image, I get strange artifacts that ...
3
votes
1answer
863 views

How to print to a specific scale with QGIS?

How can I print a map with QGIS to a specific scale? E.g. I have a map of Austria (projection: Albers equal area) and want a printout on paper at 1: 3000000?
3
votes
2answers
2k views

How to set up a plugin repository for QGIS?

I am working with python plugins for QGIS.I developed my plugin and created .zip file including my .ui,.py and resources files.In order to incooperate this plugin into QGIS i created .xml file ...
15
votes
4answers
3k views

What are data visualization and analyses pros/cons of QGIS over ArcGIS for Desktop?

Many of my colleagues use GIS on a very sporadic basis for simple data visualization and basic analysis (clipping, buffering, etc.) and I am hoping to transition these non-core GIS people to QGIS so ...
37
votes
3answers
39k views

Manually placing labels in QGIS?

Is there a way to manually place labels in QGIS? I have a map which has almost-duplicate labels in some places (e.g. E 1st St and 1st St) and I'd like to remove some of them. Also, I'd like to ...
2
votes
1answer
476 views

Automatic script to update selected records in QGIS

I am after some advice on how to produce a script that a user can run in QGIS. The script will be run against newly created feature/s (Point, Line or Polygon) that will perform not only a spatial join ...
3
votes
0answers
161 views

How to change the QGIS help dialog? [closed]

I am working with python plugins for QGIS. I am done with my one of my .py file using python 2.5 and pyqt4. It is just help file for QGIS, which i changed. I wanted to incorporate the same in QGIS. I ...
8
votes
4answers
3k views

How do I add (and map) a non-spatial table to QGIS from SQLite?

I have an sqlite file from my Wigle Android app (wiglewifi.sqlite). It's not a spatial file, just tables with lat/lon and other data. I can add spatialite layers just fine, but cannot seem to find a ...
2
votes
1answer
1k views

JOSM vs QGIS/uDIG for road network editing and storage

My application needs to store a road network and provide editing functionality for that network (editing/updating/removing lanes, signs, traffic lights, speed limits info, etc.). I find JOSM tool to ...
2
votes
1answer
1k views

How do PostGIS layers in QGIS work? [duplicate]

I use QGIS 1.4.0 to import a layer which is basically a road network converted from an .osm file to a PostGIS database table by osm2pgrouting. I have skimmed through the documentation, but I am still ...
16
votes
7answers
35k views

Viewing LIDAR data (.las) in QGIS?

Is there an easy path to visualizing LIDAR data in QGIS? I have some USGS LIDAR data in .las format downloaded from http://lidar.cr.usgs.gov/. This means I have both the .las and metadata in .xml ...
2
votes
1answer
560 views

A software architecture for viewing/editing roads and routes

I have a routing software module which uses PostGIS/pgRouting to calculate routes. The road network is generated from an .osm file with osm2pgrouting tool. I need to enhance the functionality of the ...
12
votes
3answers
16k views

How to delete multiple selected polygons at once?

I'm new at this, a novice at best. I'm using QGIS 1.7.3. I simply want to select a large number of polygons on screen and hit the delete key to delete them and resave the shapefile. Can this be done?
11
votes
3answers
15k views

How to add Raster legends in QGIS map composer?

Is there a plugin or method to add legends for raster layers (with a custom colourmap) as an item in the print composer?
2
votes
1answer
14k views

Python :ImportError: DLL load failed: The specified module could not be found

I am working on Python plugins for QGIS. I set my variables as PATH :=C:\OSGeo4W\apps\qgis;%PATH% PYTHONPATH:=C:\OSGeo4W\apps\qgis\python But when I try to run my .py file in IDLE I get an error ...
2
votes
2answers
555 views

QGIS 1.7.3 and pyqt4 version mismatch

I installed QGIS 1.7.3 using OSGeo4W installer.I have python 2.7 and pyqt4-py2.7 installed on my system.My system paths are: PATH:C:\OSGeo4W\apps\Python27\Lib\site-packages\PyQt4\uic;C:\Python27\...
21
votes
8answers
34k views

How to merge lines with slightly different endpoints in QGIS?

In QGIS, I have two lines. The endpoints are near each other, but not quite aligned. I'd like to turn the two lines into one, with the two endpoints merged into midpoints. The closest I've been able ...
17
votes
1answer
1k views

Monte Carlo simulation using QGIS and pgRouting on optimal sidewalk construction

I am new to spatial analysis and would appreciate some general direction on a project I am attempting, outlined below (I am starting from scratch). GOAL: To find the best locations to install 2000 ...
0
votes
1answer
1k views

libmysql.dll-procedure entry point error [duplicate]

Possible Duplicate: How to fix QGIS error “Entry Point could not be located”? I am working with qgis,pyqt4 and python2.5. I was getting error qtcore4.dll could not be located.so i set ...
3
votes
1answer
392 views

How to import selected features from QGIS to PostGIS?

I am trying to import selected features from Quantum GIS to postgresql directly. I do not know how to do it. Actually, my problem is, I have full country road network. But, I need to cut road network ...
1
vote
1answer
15k views

How to fix Qtcore4.dll can't find procedure entry point? [duplicate]

Possible Duplicate: How to fix QGIS error “Entry Point could not be located”? I am working with QGIS, python2.5 and pyqt4 for py2.5. My system variables are as follows: path:=C:\...
3
votes
2answers
2k views

How to fix for the GDAL clipper tool in QGIS?

I would like to clip a DEM with an admin boundary using qgis, in order to calculate a measure of variation. However, when I use the Raster clipper tools and select mask, I get the error message: "An ...
1
vote
1answer
170 views

Render a raster with hue values in QGIS

I have a single-band raster (a GeoTIFF) with hue values in the band. I'd like to render it, preferably in QGIS but another open-source GIS would be acceptable as well. The saturation and value should ...
4
votes
2answers
2k views

How to reproject from Michigan Georef to WGS84 in QGIS?

I am trying to reproject a michigan state land shapefile which is the NAD83/ Michigan Oblique Mercator EPSG:3078 to the WPG84 EPSG:4326 projection. However when i try to do this my map gets squished ...
22
votes
5answers
13k views

Optimal video cards for GIS programs [closed]

I recently purchased a Dell XPS-8300 (i7-2600|16 GB DDR3 RAM|64-bit Windows7) which I intend to use primarily for GIS programs. I bought a refurbished model because it was much cheaper and because I ...
32
votes
4answers
16k views

Is there a way to render lines with a smooth (bezier) curves in QGIS?

I am moving from creating maps with Illustrator to making them with QGIS and actual data. One of the things I haven't been able to re-create in QGIS are the smooth curved lines I can get in ...
10
votes
2answers
4k views

How to only show labels for an arbitrary selection of items?

I'm curious how others go about solving this problem: You've created a map for something with a large number of features that are labeled. The customer/client asks that you only show labels for X, Y ...
5
votes
1answer
3k views

How to use QGIS Time Manager sample data?

I've downloaded the Time Manager plugin for QGIS for Windows, version 1.7.1. I'm not sure whether I should really be asking a question on here, but since there doesn't seem to be an issue tracker on ...
11
votes
2answers
2k views

How to Create Two Color Lines in QGIS?

I've been working on making mountain biking and hiking maps using Illustrator and I am now trying to move to QGIS so there's real GIS data powering the maps, making updating/scaling them easier than ...
13
votes
3answers
40k views

Create a new layer from overlap between two layers?

I'm new to desktop GIS, and will try to ask while lacking the proper terms from the GIS lingo: If QGIS was like Photoshop I would like to make a selection from one layer, and then match that ...
2
votes
1answer
2k views

Quantum GIS Reproject a projected coordinate system with rotation

I have two shapefiles:- one in WGS84 Z30S and one in a custom, system based, projection. I need to convert the custom projection into WGS84 Z30S. I have a set of parameters including a shift in X and ...
2
votes
1answer
157 views

Does QGIS support MT83F

Does QGIS support NAD83 Montana State Plane Zone, US Foot? I have vector data in a CSV file that I would like to display, but the coordinate system is MT83F. I don't see a matching CRS. Is there a ...