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
241 views

How to sum up all field values in QGIS modeler

I am building a model to generate two zones around a point, a 250m-buffer, and a ring of 250 to 1000m, where i recalculate values from an other layer according to the intersections share. The purpose ...
2
votes
1answer
342 views

How can I show points on the same coordinate as e.g. a bigger symbol in QGIS?

I use QGIS 1.8 for mapping archaeological findings. Some of the findings within one layer are located on the same site and therefore have the same coordinates. Therefore you just see one point instead ...
3
votes
1answer
399 views

How to join 2D polylines and DEM into 3D polylines?

I got a simple question but could not find a satisfactory answer yet: I have a road network in 2D/PostGIS and a DEM. I want to turn the road network into 3D by retrieving the Z-value from the DEM. ...
2
votes
0answers
165 views

Our best table-analysis with GIS? [closed]

Sometimes I think about possible analysis using GIS models (I use QGIS 1.8), and I always think about few types of visualization techniques: demographics, traffic flows, distance ones... Thanks to ...
1
vote
0answers
114 views

Error: basic_string::_S_create, (trying to use .ecw files)

I have a problem, after resolving my problem with: .ecw is not a supported data file. I am in a new one. When I try to load an .ecw file in QGIS it says: basic_string::_S_create
2
votes
2answers
3k views

How to add csv file in QGIS 2.0 using Delimited Text Layer Plugin?

I used to import csv files in previous versions of QGIS using the format below, but when I upgraded to QGIS 2.0 the delimited text layer plugin was changed and I can't import the file anymore. The ...
3
votes
2answers
2k views

How to load MrSID raster layer in QGIS on Mac OS?

I have just upgraded QGIS to 2.0 and now I can't load my SID raster layers. I now remember that getting them into 1.8 was a performance but I can't remember all the details. I have downloaded the ...
3
votes
0answers
140 views

Handling non-spatial data for QGIS projects with Camelot

Most of my projects include data which is non-spatial or which is point data and can be managed by a regular relational database. Previously I found Manifold and ms-access were a good combination ...
1
vote
0answers
502 views

QGIS connecting to ArcGIS world imagery - not loading correctly

Have connected QGIS to ArcGIS World Imagery using python console as described on http://www.northrivergeographic.com/qgis-adding-an-arcgis-rest-service. QGIS Seems to connect and make a raster layer ...
1
vote
2answers
911 views

OpenLayers plugin for QGis problem with maps loading

I am new in GIS. I use QGis 2.0.1 with OpenLayers plugin downloaded from official repository. When I click to Add OpenStreetMap layer the map is not showing and load process is neverending. What is ...
2
votes
1answer
165 views

Can I Turn Off or Remove Map Layers in QGIS Print Composer

The title pretty much says it all. I have a base map in QGIS that I am using with several Print Composers. In one of the Print Composers, I don't want one of the layers to show up. Is there any way ...
2
votes
1answer
51 views

QGis - QgsComposerScaleBar - nearest km

I added a QgsComposerScaleBar to a QgsComposition. I wish to have segment rounded to the nearest km but I don't know how to achieve this. Thank you in advance.
1
vote
0answers
252 views

Couldn't load PyQGIS, QGIS 2.0.1 on Ubuntu 12.04 Precise

After upgrading to QGIS 2.0.1 I still get the error: Couldn't load PyQGIS. Python support will be disabled. Traceback (most recent call last): File "", line 1, in File ...
0
votes
2answers
666 views

JP2 fails to open in QGIS and GDAL

I am trying to open a JP2 file in QGIS and it fails, and I'd appreciate any advice to try and track down the cause of the issue, be it with my system or with the file itself. The file is a HiRISE ...
1
vote
0answers
60 views

QGIS mapserver - fails to display some raster images

QGIS 2.0.1 running on Linux, with mapserve support. Randomly, it seems, some raster images simply fail to display. No errors, just no image (well actually the mapserve returns a blank white image). ...
1
vote
2answers
447 views

Calculating millions of distances with Road Graph

I'm new to GIS but thanks to the answers I got in another question here on GIS stack exchange I was able to increase my knowledge significantly. This question is related to an earlier question I asked ...
3
votes
2answers
477 views

Access all plugin from QGIS Modeler (Sextante)

I read that it is not possible to access to all of the installed QGIS plugins from the Graphical Modeler (QGIS 2.0.1). It would be great, in defining the model in the Graphical Modeler, if the user ...
5
votes
1answer
148 views

fTools “Join Attributes by Location” missing in SEXTANTE/Processing Toolbox

I am working with the new Processing Framework in QGIS 2.0.1. I really like the graphical modeler, because it allows my to make my own tools without having to be able to write pyhton or any other ...
2
votes
2answers
351 views

What is faster for geoprocessing (intersect) big shapefiles?

I have 200 Mb shapefiles of polylines downloaded from OSM. I've been working with QGIS 2.0 in Ubuntu 64 Bit 8 Gb RAM to make some geoprocessing tasks and it's taking 2 days for processing. Once I've ...
2
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
283 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() ...
3
votes
1answer
273 views

creating an OD cost matrix in QGIS

I'm a new user of QGIS with limited programming skills (I prefer using menus...). Can anyone help me finding a resource which will guide me through the steps required to produce an origin-destination ...
0
votes
2answers
125 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
298 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
611 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
176 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
381 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
354 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
176 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
495 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
265 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
2k 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
366 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
111 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
276 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
76 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
133 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
696 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 ...
1
vote
2answers
551 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
458 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 ...
5
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 ...
4
votes
4answers
2k 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
474 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
204 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
110 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
302 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
86 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
235 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.. ...
1
vote
2answers
5k 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 ...