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

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6
votes
2answers
1k views

Tilemill Dynamic Tile Generation

I have recently used Tilemill and I wish to implement it for dynamic tile rendering.As I've seen an CartoDB doing in cloud system,they can query & generate dynamic tile for request with UTFGrid. ...
2
votes
1answer
119 views

Where can I get a comprehensive list of Rules expression operators?

I'm selecting and styling my points layer on a contour map of Philadelphia using Rules Based Styling. (see: Can I use rules based rendering in QGIS to select features?). The filtering process using ...
0
votes
1answer
112 views

How Could I Calculate Shortest Path ?

I am working on QGIS - 1.8 Version and frequently getting an error while using Road Graph and Shortest Path Opetions. Kindly Suggest or provide solution.. With Regards Prashant Persai
2
votes
2answers
152 views

Generating new shp files according to attribute in QGIS

I know that it is possible to color a vector map by attribute. I separated a map into 4 colors based on an attribute and now I want to generate a new map for each color. Is there a way to do this in ...
3
votes
1answer
565 views

How to make survey lines within polygon?

I am trying to figure out how to make survey lines within a polygon. So first I make a polygon. Now I need to fill this polygon with lines, where I can choose the spacing between the lines, and the ...
2
votes
1answer
65 views

QGIS VPAT; Section 1194.21(c)

I am attempting to fill out a VPAT for QGIS so that it can be made more accessible in the federal IT environment. I could use some help and wanted to explore this venue as a means of getting it. If ...
2
votes
0answers
34 views

Automatic insert of project name into database

For every layer I've a field in my postGIS database that should be filled with the name of the current project and today I do this manually. Is there a way to do this with the Commands that can be ...
16
votes
2answers
2k views

Creating Thiessen (Voronoi) polygons using lines (rather than points) as the input features?

I have a set of line features inside a particular polygonal boundary. For each line, I'd like to generate a polygon inside which every possible point is closer to the given line than to any other line ...
1
vote
1answer
482 views

QGIS Sextante Python UnicodeEncodeError

I have some issues with Quantum Gis 1.8. When I try to use shapes to grid (sextante-saga tool) I get the following error (comes up when I try to define the new grid file name): Fehler bei der ...
1
vote
2answers
553 views

How to mask out features outside of the Coverage Layer for Atlas plugin? [duplicate]

Using the Atlas plugin for qGIS how do I set the coverage so that it will only highlight the feature(s) I want but still show the surrounding features as grayed out areas? This would have been easy ...
1
vote
0answers
693 views

Lines as Great circles on a map

How can I get line features to appear as great circles on a map, instead of straight lines? Thanks,
2
votes
1answer
116 views

QGIS mixing up CRS

I´ve just started working with QuantumGIS for my thesis. I ordered shapefiles with the CRS: ETRS 89 UTM Zone 33N, but QGis layer properties now shows the layer has a different CRS (namely SWERE99 TM) ...
6
votes
2answers
1k views

Defining bounding box within Add WFS Layer dialog of QGIS?

I use QGIS 1.8 under WIN XP in Standalone Installer Version. I need to limit the extent of the data to be downloaded via WFS because of the large amount of data in the requested layer. In ...
2
votes
0answers
104 views

QSpatiaLite: Cannot create table

I am running QGIS 1.8 (SpatiaLite 3.0.1) and QSpatiaLite 6.0.1. I have a spatial table EventPrecise (with geometry column p in EPSG:4326). I want to join this table with another, non-spatial table ...
3
votes
0answers
118 views

QGIS Workflow Problem [closed]

I have 3 SpatiaLite layers (one without geometry but with fields that need to be filtered, one with points and one with polygons, both without any non-geometry fields) that need to be combined to a ...
4
votes
2answers
606 views

Setting coordinate systems in gvSIG: Is the workflow similar to QGIS?

I am still learning how to use coordinate systems and projections, but I hope this basic question will be easy to answer. My goal is to be able to use either QGIS or gvSIG to create a simple county ...
5
votes
1answer
393 views

How do “join field” and “target field” work?

New user. This should be simple, but I can't figure out how to perform this basic join in QGIS. (It works in Cartographica.) My shapefile (IL_BNDY_County_Py) has two fields/columns in its attribute ...
1
vote
0answers
56 views

How to extract elevation data from DEM along a polyline [duplicate]

I've been trying to use qGIS to extract and save as an attribute the data elevation along a line, knowing that something similar is available in ArcGIS using the Spatial Analysis tool. So far, ...
2
votes
1answer
494 views

QGIS Routing between two Points without Roads

I'm using QGIS 1.8 and i need to analyze possible routes for roman roads. Is there a Possibility to show routes which comply special criteria, e.g. straightest way between two points, or path which is ...
2
votes
1answer
1k views

How to convert lines from dxf to polygons?

I have several dxf files. Each file, contains the 0 layer. The 0 layer contains lines (which make a closed polygon). In each dxf the lines have their color and line width. I do not have autocad or ...
4
votes
1answer
321 views

How to auto-start a pyQGIS thread?

having build some (two) minor plugins, it's now time for me to link a few (perl-) applications to qgis. As there is no perl-interface in qgis I thought the best way to link both worlds together is a ...
3
votes
2answers
164 views

I am unable to draw a shape layer

When I add a new shape layer or want to edit an existing one, nothing is happening. I even don't see the dots where I'm clicking. Maybe the problem is I deleted some layers (by opening the .qgs as a ...
1
vote
1answer
463 views

How to Georeference a tiff with correct coordinate system

I am having difficulty in georeferencing an existing tiff (already has georeference information - but is out of alignment). Using the georeference plug-in I can create the map's GCP in the 4 corners ...
2
votes
2answers
167 views

QGIS 1.8 on Ubuntu 12.04 doesn't transform CRS properly

I have a weird QGIS-Problem that only occurs in Ubuntu 12.04, but not in Windows 7. I've also tried this on different Ubuntu-Computers. When I try to transform a layer with WGS84 to a different ...
2
votes
2answers
2k views

How can I link java with QGIS?

I want to create a Desktop project on Java which shows radiation dispersion. How can i Link java with QGIS? Is there any tutorial site i can get reference from?
4
votes
1answer
314 views

How to connect waypoint pairs and calculate length?

I want to make a path out of points and calculate the distances of each single line. I have a point layer with waypoints of a research vessel. The way points have in the attribute table a date and a ...
4
votes
2answers
281 views

Connect to PostGIS using SEXTANTE in QGIS

I have a localhost PostGIS database that I would like to use with SEXTANTE in QGIS. I can connect to the database just fine using "Add PostGIS layers...", but when I try "PostGIS execute SQL" in ...
1
vote
1answer
41 views

How to report issues with QGIS documentation?

I stumbled across a gotach while installing mod_fastcgi on MacOs 10.8 (mountain Lion) -- there is a bug in 10.8 in the apache build env which breaks the install instructions here: ...
4
votes
2answers
580 views

Can't select layer to upload to GPS

I'm trying to upload a vector layer to my Garmin GPS unit. I've saved it as GPX (WGS 84); opened the GPS Tools dialogue in QGIS 1.8; selected the "Upload to GPS" tab; and clicked on the "Data layer" ...
0
votes
0answers
560 views

QGIS 1.8.0-Lisboa DBmanager (OSx) can't connect to remote PostGIS 2.0.2 database (Debian)

The PostGIS database is remote but I have made changes to the Postgresql config files and can access it remotely via pgadmin. When I open DBmanager in QGIS I see a note on the bottom that says ...
3
votes
1answer
1k views

Handle add new feature event and/or access feature before commit?

Is it possible with PyQGIS to catch "add new feature" event before commiting changes on the layer? or at least to access new features before commit.
8
votes
2answers
603 views

How to avoid duplicate GIDs when copying features from one PostGIS layer to another?

When I enter new elements (features) in another Postgres layer, I can do it in two ways: Drawing new element(s) (with 'Add feature') which I do rarely or Copying (or cutting) some elements from ...
0
votes
1answer
208 views

Postgresql on Ubuntu Server and QGIS [closed]

Complete newbie... I taught myself the basics of GIS on the job with ArcGIS 9.3. I have been plating with QGIS and have gotten the basics down on both. I am not well versed in the terminology related ...
3
votes
0answers
154 views

Is there a tool for automated quality assurance for vector data captured on raster data?

I wonder whether is any tool(or script) in ArcGIS or QGIS which allows to make an automated quality assurance for vector data captured on raster data? vector data on binary raster:
1
vote
1answer
158 views

“ERROR: invalid input syntax for integer” importing data from Spatialite into PostGIS through DB Manager

I am trying to import data from Spatialite into PostGIS through drag and drop in DB Manager but all I received was an error: Feature write errors: Creation error for features from #1 to #202. ...
3
votes
1answer
230 views

How to display only one representative contour line in legend?

I have a layer of topographic contour lines, graduated by color (using QGIS). My legend wants to display every level and its color. This is not feasible. I need to simply show one representative line, ...
6
votes
2answers
2k views

Why do my Shapefiles not align correctly?

First: I'll summarize what I understand so far so please confirm or correct me. When On-the-Fly is selected a layer is re-projected from that of the layer's CRS to that of the project CRS, IF ...
3
votes
1answer
988 views

How to get the distances (shortest path) between all pairs of points in the river network?

I have 2 vector shapefiles (one line, one point), and I have tried at least 4 ways to try to get the distance matrix at one time (and most concern the directions of each river segment) quantum ...
4
votes
1answer
500 views

How change border line to no pen with python console?

From Python console I load a shapefile with qgis.utils.iface.addVectorLayer. How I can remove border lines (change to no pen) in the active layer?
4
votes
1answer
165 views

QGIS field calculator and Postgres permissions

I’ve given user x the following GRANT ALL ON ALL TABLES IN SCHEMA y TO x; GRANT ALL ON ALL SEQUENCES IN SCHEMA y TO x; GRANT ALL ON ALL FUNCTIONS IN SCHEMA y TO x; However in QGIS they dont have ...
2
votes
1answer
947 views

QGIS opening shp file: why does it crash?

I am trying to open a shp file from the EEA (Urban Atlas), and with some of the shp files qgis keeps crashing as soon as I try to load it. QGIS 1.8.0 is running on Windows 7; I reinstalled QGIS, ...
5
votes
1answer
163 views

What projection is this and how to use it in a GIS?

I have a request to do a map in non-standard projection: (source: http://www4.agr.gc.ca/AAFC-AAC/display-afficher.do?id=1263246127905&lang=eng) I couldn't manage to find it my materials. As well ...
6
votes
1answer
612 views

How to add attributes in proportion to intersecting area from another layer

I am new to using QGIS. I have two polygon layers: Voronoi of Access Points Census block maps with population I want to get number of people covered by each Access Point (Assuming uniform ...
5
votes
1answer
1k views

Pansharpening in QGIS

I was wondering if anyone has successfully been able to perform an image pansharpening within QGIS? I have utilized OpenEV to do this, but the results have been very pixelated. Any info would be ...
2
votes
0answers
52 views

vector cropping failure

I’m trying to crop a vector contour layer using the instructions given at http://lists.osgeo.org/pipermail/qgis-user/2012-February/015294.html . I created a polygon in a newly-created vector layer, ...
6
votes
3answers
2k views

How to create a polygon with specified dimensions?

I'm editing a shapefile in QGIS and want to draw in a rectangle with specified dimensions(Say 101ft by 305ft for example). Is there a way in QGIS to make draw a rectangle with out actually have to ...
1
vote
1answer
163 views

Get feature while editing

I have created my custom form for features editing, using layer.setEditForm("form.ui") and layer.setEditFormInit("init") properties. init method receives dialog, layerId and featId as arguments. ...
0
votes
1answer
187 views

Can you reduce the number of contour lines? [duplicate]

Using QGIS, is it possible to reduce the number of contour lines in a hypsography (topographic) layer? Mine has them every 5 meters, which is more than I need and it makes the map awfully busy.
2
votes
0answers
208 views

oil palm stand census algorithm

Anyone have experience in oil palm stand census using tree detection algorithm from satellite images in ArcGIS or QGIS? any references for usable algorithm? What is the accuracy? thanks for help.
0
votes
1answer
435 views

Using macports python 2.7 with macports qgis

I installed qgis through macports on my mac running OSX 10.8.2 but when I run the application (qgis 1.8) it says that I don't have python-gdal installed. I searched google and it appears that it is ...