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

learn more… | top users | synonyms (1)

3
votes
1answer
2k views

How do you import simple xyz in QGIS

I have found out how to get tab-delimited X,Y data into a layer but the Z field value is not given as an option on import? I tried to edit the attributes to add and define a new field but it keeps ...
4
votes
1answer
331 views

Create MultiPolygon from QgsGeometry.fromMultiPolygon

I have a list of polygons' points like [[x1,y1],[x2,y2],[x3,y3],[x4,y4]] [[x5,y5],[x6,y6],[x7,y7].[x8,y8]] now I want to create multipolygon from it by using feature = QgsFeature() ...
6
votes
3answers
486 views

How to create an OD road distance matrix in QGIS?

I'm looking for the steps required to produce an origin-destination (OD) cost matrix. What I'm looking for is a matrix of road distances. The distance matrix tool only produces euclidian distances. ...
0
votes
3answers
161 views

Installing QGis such that it will work with the Postgres.app implementation of PostgreSQL on Mac (Lion) (open to alternative implementations)

I just got a new mac and am getting everything installed on it (postgres, postgis, qgis, grass, gdal, brew, ruby, etc) and am about to install QGis. QGis is a great tool for me, except for that with ...
2
votes
1answer
406 views

How to find unique values of an attribute with python in qgis?

i look for solution to get the unique values of an attribute of a vector layer. what is the best way in python qgis to get the unique values of one distinct attribute? I work with qgis 1.8.0.
1
vote
1answer
844 views

OpenLayers from behind a proxy

I'm trying to get the QGIS OpenLayers plug-in to work from behind a proxy. I've set up all my proxy details and this has had the effect of allowing QGIS's Manage & Install Plug-Ins tool to work ...
1
vote
0answers
246 views

Incorrect coordinates when reprojecting NAD27 to NAD83

I have some historic UTM coordinates as NAD27 (556787, 7169250) which I entered into a spreadsheet and have imported into QGIS. I assign them the projection Nad27 / UTM zone 12N (EPSG: 26712) I ...
2
votes
1answer
495 views

How do I convert longitude & latitude to a 3d (geocentric x,y,z) coordinate?

I'm interested in finding the centroid of a point cloud. I understand that to do this I need to convert latitude and longitude values to 3d coordinates, average them and then convert the resulting ...
1
vote
1answer
411 views

How to use UUID Generator in Qgis 2

I try to generate a UUID (edit widget) for a vector shapefile in qgis 2 but the field value is always NULL. Does the field requirea specific datatype? I used integer. In the manual I found the info ...
2
votes
1answer
249 views

How can I lock the scale when panning?

I'm just wondering if there's any way to easily lock the map scale when panning etc. For example, suppose I set the scale to 1:100,000 - panning with the mouse will then alter that slightly, which can ...
1
vote
2answers
572 views

Error .ecw is not a supported raster data source

I am a user from Spain and a I have recently installed QGIS 2.0 in my computer which has Ubuntu 13.04 and when I try to use an .ecw file it says: Error, .ecw is not a supported raster data source. I ...
1
vote
3answers
290 views

Differences between SQL dialects in QGIS vs ArcView vs Oracle

I'm kinda new with SQL queries and there is something I don't get: A SQL query in QGIS is written differently than the same query in ArcView and will probably also be written differently if I want to ...
0
votes
1answer
4k views

How Can I change the projection of shapefile in Qgis?

I have a probleme with Qgis. I would like to change the projection of my shapefile, it's about caves in my country. The default projection is set to EPSG:3003, I want to change it to wgs84 EPSG:32632. ...
1
vote
1answer
461 views

How to sum up multiple columns values into one single column

I have one table containing many columns. Using field calculator, I want to create a new column containing (for each line) the sum of all columns values. Pretty dumb, but just cannot find the correct ...
1
vote
0answers
120 views

Converting custom grid to OS grid

I have two sets of data, one is in OS coords, no problem there, but the other was set out in about 50 off 10x10 metre grids aligned to a 'feature' on the ground. I do have the OS coordinates of their ...
4
votes
3answers
336 views

How to create non-overlapping street polygons from centerlines?

I want to create non-overlapping polygon layer from center line by applying the buffer to line layer in postgis. I am able to create polygon layer but how to avoid or resolve overlapped polygons. ...
1
vote
0answers
78 views

QGis 2.01 Fedora 19 vs Windows SQL-Server Access

i just installed QGis 2.01 on Ubuntu / Fedora 19 / windows 8, configured ODBC-support for Fedora 19 and created ODBC-DSNs on the windows machine and the Fedora machine to the same SQL-Server 2012 ...
3
votes
1answer
163 views

QGis: Difference between Mac OSx and Windows

i try to import a KML-Placemark file with QGIS (--> Add Vectorlayer, UTF-8). When i import the File with my Mac (OS 10.6) i don´t have any problems viewing all the attributes stored in the KML-File ...
1
vote
1answer
891 views

Delineate polygonal catchment areas from a raster using open-source GIS

I'm 90% sure this basic question has been asked before but looking through the other posts I simply do not see a useful answer. I need to calculate polygonal(vector) catchment areas from a raster ...
2
votes
2answers
789 views

Import Zip codes into qgis

I have a list of zip codes (nearly thousands) which I want to show in qgis. After researching I found that I need to geocode them first into Lat/Long then I can use them to create a layer for qgis. I ...
3
votes
1answer
651 views

How to save a QGIS 2.0 project template?

When I attended the QGIS in Action workshop at FOSS4G13 Tim Sutton mentioned there was a new option to save a project as a template which when you opened up a new QGIS project you could pick to choose ...
7
votes
2answers
1k views

How to remove small “salt & pepper” polygons from a layer?

I have a map made up of multiple polygons, with a few hundred thousand points very small polygons on within it. I need the larger polygons, but not the points small polygons. How do I select and ...
6
votes
1answer
2k views

Shortest distance from point to line (big dataset)

What is the best method to calculate the distance from the nearest road for a series of address points in QGIS, having a very big dataset? (QGIS 2.0.1, Win XP) I read the answers to previous similar ...
5
votes
4answers
4k views

What is the projection of WGS84 in GIS software?

WGS84 is a reference ellipsoid that determines coordinates of every point on Earth using latitude, longitude and height about the its surface. This ellipsoid is often used as a base to make maps. ...
0
votes
1answer
534 views

GRASS in QGIS not working (windows XP)

I am unable to use GRASS algorithms in QGIS 2.0.1 (on windows xp). I've already configured the GRASS path. The algorithms seems to work correctly (I cannot see errors in the log), however in the end ...
2
votes
3answers
235 views

Census.gov TIGER down, suggestions?

Census.gov is down for now. I have a friend who is a teaching a GIS class in the San Francisco bay area and only has so many datasets downloaded for specific projects. Does anyone have a large copy ...
0
votes
1answer
122 views

Failure to install QGIS 2 - held broken packages

I pasted the issue about not being able to install QGIS 2 on Ubuntu Raring on an ubuntu forum: launchpad.net apt questions and the answer seemed to indicate the problem is with QGIS? Thread: ...
2
votes
1answer
342 views

QGIS 2.0 - 2.4: Color Ramps Missing?

Since QGIS 2.0.1 the default color ramps and styling symbols seem to disappear for some users. For me, this started with QGIS 2.0.1 and still consists with 2.4. I can neither choose Smybols when ...
0
votes
1answer
91 views

Shortest path to nearest… something

I have a list of addresses and a map including train stations, schools etc., and I would like to calculate the shortest distance from each address to the nearest train station, school etc. I'm aware ...
1
vote
2answers
299 views

Where I can download QGIS 1.8 for Mountain Lion?

I've encountered some problems running my old 1.8 project in 2.0. I would like to reinstall QGIS 1.8 but seems that there are no more 1.8 installer in KingChaos. In QGIS "all releases" there isn't.. ...
2
votes
2answers
7k views

How to Merge/Dissolve Polygons By Common Attribute Field in QGIS?

I have joined corresponding Local Enterprise Partnerships table data into a polygon shape file containing UK Local Authorities. How do I Dissolve or Merge the the Local Authorities polygons by ...
0
votes
1answer
577 views

Is it possible to load an .las file directly into QGIS? [duplicate]

Is it possible to load an .las file directly into QGIS? I would like to be able to load LiDAR data and to be able to do analysis based various feature attributes; e.g., elevation, classifications, ...
1
vote
1answer
583 views

(partly solved) Only pink tiles using Qgis Server

My name is Alfons and I'm beginning to work with QGIS Server. I'm an architect, so that I'm used to buildings and landscapes, not to scripts and code. Last 6 months I managed to work with GeoServer ...
3
votes
1answer
765 views

How to use the field calculator's centroid() Geometry function in qgis 2.0?

There is an option in the field calculator for centroids under geometry which when you double click gives you "centroid( ". What information is required here in order to use this function?
6
votes
2answers
3k views

How to install SAGA 2.1 with QGIS dufour on Windows?

I need that someone tell me how i can install saga in qgis 2.0 correctly in windows, because if I install QGIS 2.0 and when I try to use SAGA I get this Missing dependency.This algorithm cannot be ...
0
votes
1answer
142 views

Is there a way to run st_split from within QGIS?

Is there a way to run st_split from within QGIS? I am looking to split a polygon with a line feature. My data is stored in a PostGIS database, and I would like to perform this operation from within ...
2
votes
0answers
40 views

How to search for layers in the layers panel?

I have QGIS projects with a lot of layers. Sometime it's difficult to find a layer into Layers Panel. How to search it?
3
votes
1answer
1k views

How to correctly set up Oracle connection parameters?

Just testing out the new QGIS2 install here and trying to connect it to our huge SDE/Oracle spatial database. Im struggling with the connection parameters. Here is the connection properties to the ...
1
vote
1answer
172 views

How can I add a delete button to feature forms?

I have created some formulars in QTDesigner for capturing and manipulating data in QGIS. The data is stored in a postgis-database. It would be helpful to have a delete-button in this formulars to ...
0
votes
0answers
52 views

Dissolving overlapping polygons - issue in QGIS [duplicate]

I have the OS Code-Point map which I want to dissolve into the regions that my company use. I have used the dissolve function in QGIS, but it is having a problem where a vertical street overlaps with ...
2
votes
0answers
59 views

How do you compute vertical transformations in QGIS?

How do you compute vertical transformations in QGIS? Ideally, the procedure / plugin will allow the loading of sundry geoid models.
0
votes
1answer
111 views

How do I install mdenoise?

How do I install mdenoise in GRASS 6.4.3? I've already successfully installed r.denoise, and have downloaded mdenoise from wget http://www.cs.cf.ac.uk/meshfiltering/index_files/Doc/mdsource.zip. How ...
1
vote
1answer
2k views

Yum Install QGIS on CentOS 6

I was trying to install qgis on centos 6.3 and follow the instruction here. However after running yum install qgis qgis-python qgis-grass qgis-mapserver I got below errors: ---> Package ...
3
votes
2answers
1k views

QGIS 2.0 64bit Orfeo Toolbox Installation Failure

I am trying to install OTB in with QGIS 2.0.1 (Dufour) in Windows 7, 64bit. I have no problem installing QGIS either the QGIS installer or OSGeo4W, but I have no luck with the OTB tools such as ...
0
votes
1answer
44 views

How to keep NULL values in attributes until the user choses from the value map?

When I set up a attribute domain by using value map in QGIS then create a feature which in turn pops up the attribute pop up window - the value mapping for the attribute inserts the first value from ...
0
votes
1answer
100 views

Shapefile rotated after displayed on Bing Maps

I took shapefile of country here http://thematicmapping.org/downloads/world_borders.php Then opened in QGIS, after that save needed layer to KML file and took coorditaes for displaying polygons var ...
1
vote
1answer
98 views

How to find out to which polygon each points belongs to?

I have searched for an answer to this, but couldn't find anything useful. I have got a shapefile consisting of a number of polygons, and another shapefile with a number of points. I want to add a ...
0
votes
2answers
1k views

How to fix ImportError: cannot import name MAXREPEAT on Ubuntu 12.04

I have problem with installing qgis 2.0 on ubuntu 12.04. If I don't install qgis-python plugin then qgis starts normally but I can't access python console in plugins. If I install that plugin then I ...
1
vote
2answers
173 views

QGIS point sampling tool really slow for polygons?

I have a large field of randomly distributed points (100,000 of them to be precise), and I'd like to get values for a variety of raster and polygon coverages for each point. I've been using the QGIS ...
4
votes
1answer
1k views

What is the procedure to load LAS files in QGIS 2.0.1?

What is the present procedure to load LAS files in QGIS 2.0.1? After some searching I found a paper outlining the procedure; however, it was for 1.8.something, and related posts here are all rather ...