Questions tagged [qgis]

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

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11
votes
2answers
8k views

How to use label classes, expressions, and annotations?

I've always found that when it comes to python, vector analysis, QGIS gives ArcGIS a run for its money, hell some of the qgis plugins exceed ArcGIS's performance by a few hours; however, I always have ...
7
votes
3answers
4k views

How To Convert A Set of ARC/Info ASCII .e00, .e01, .e02, etc Files Into .shp Files

I have a set files that I downloaded with extensions (.e00, .e01, .e02, etc). I have read that these are files used by ARC Info mainly, but I do not have ARC and nor am I really that interested in ...
8
votes
2answers
1k views

Are there any tools / plugins to develop mapbooks using QGIS?

Are there any tools / plugins to develop mapbooks using QGIS?
4
votes
1answer
863 views

ESRI pgdb in QGIS

Using OSGeo4W 1.5, when I go to add vector layer and select file type, navigate to my ESRI pgdb. I get a not a valid or recognized data source. If I use the database type I get a page that defaults ...
12
votes
2answers
8k views

Derive WGS84 Longitude & Latitude from British Northings & Eastings

I'm looking for a fairly simple way to append columns with WGS84 longitude and latitude to a table containing northings and eastings. The source data is Ordnance Survey's CodePoint Open, which I is ...
3
votes
3answers
336 views

Trouble getting metacarta to work with QGIS

I have a basic issue with getting QGIS to accept the metacarta WMS service and wonder if anyone can guide me. I add the "basic layers" to the map, but still can't see the tiles there when I go to the ...
17
votes
4answers
6k views

Shaded relief from DEM in GRASS and QGIS

I have been trying to get a good looking shaded relief model out of GRASS and Qgis for a day or so now and just can't seem to get it. The biggest problem I'm having is the valleys look like mountains,...
20
votes
2answers
37k views

Controlling Image Output Settings in QGIS?

I am exporting a QGIS map to an image format. I would like to have control over the output settings of the image (dpi), as currently it is only exporting the images at 96 dpi. Does anyone know if ...
10
votes
9answers
12k views

Extract boundary from detailed layers in ArcGIS Desktop or QGIS?

Is it possible to return the boundary (outside) perimeter of a polygon layer? Let's say you have the map of the USA, for simplicity, broken down to the county level, is it possible to return the ...
53
votes
13answers
19k views

Seeking QGIS tutorials and web resources?

I wish to familiarize myself with the capabilities of QGIS up to and beyond QGIS version 3.0. Can you recommend some good web resources and tutorials that would show me QGIS' capabilities? I am ...
4
votes
2answers
512 views

Misalignment when generating centroids with QGIS

I was wondering if anyone could shed a light on why this behavior is happening in QGIS? I'm pretty confident that the issue here is not due to centroids within polygon. Edit Added a detailed image
3
votes
1answer
585 views

Is QGIS compatible with PostgreSQL 8.4 Advanced enterprise DB with Oracle compatibility?

Sorry for such a long question. We are trialling EnterpriseDB Postgres Plus Advanced Server 8.4 with Oracle compatibility and PostGIS 1.5.1. I can create a connection to the database in qgis and the ...
9
votes
1answer
3k views

Tiled Map Services from Geowebcache in QGIS?

Can QGIS consume Tile Map Services from GeoWebCache? I know there is a article on the QGIS website which states that it does support tiled map services but it lists Tile Cache from Meta Carta labs ...
6
votes
3answers
2k views

Altering composer label items in QGIS with Python

I'm only new to QGIS and Python so this may exists already, and hopefully be easy to do. What I'm hoping to do sometime in the future is build a map book generator using QGIS as the base. In order ...
6
votes
2answers
10k views

How do you Turn on the GRASS plugin in Quantum GIS?

I downloaded and installed Quantum GIS 1.5.0 with GRASS using the OSGeo4W installer on my Windows XP machine. Unfortunately, when I go to Plugins>Manage Plugins I cannot find the GRASS plugin. When ...
6
votes
1answer
4k views

How to clear python console in QGIS?

After running several hundred lines of commands (and getting their subsequent error statements...), it is nice to be able to clear out the console window and start clean. In the Python Console ...
4
votes
3answers
11k views

Measuring polyline using either QGIS or ArcGIS Desktop?

I've collected a bunch of GPS polylines (WGS84). What is the easiest way to measure the length of these lines in KM using QGIS or ArcGIS Desktop?
7
votes
4answers
4k views

Quantum GIS and ECW images?

How might I enable Quantum GIS to read ECW imagery? At the moment I'm mostly concerned about this on Ubuntu 10.4 amd64, but I also use WinXP & Win7.
9
votes
1answer
2k views

How to read/write from/to QGIS project file using Python?

I'd like to save the project-dependent configuration of my Python plugin inside the QGIS project file. Is this possible and what are best practices to do so?
12
votes
2answers
4k views

How to toggle layer visibility in QGIS using Python?

How can I toggle layer visibility in QGIS via Python API?
6
votes
1answer
4k views

Using QGIS to fix invalid geometry without saying not allowed?

I have a shapefile, and it's got a self-intersecting geometry in it. I'd like to fix the self-intersection, but it will require a few moves. When I attempt to move a point using the QGIS edit tools, I ...
4
votes
1answer
4k views

Connecting to WMS, but only getting blank pages

I have a problem connecting to my WMS service. In ArcMap I can connect but, what I see is only blank page (cannot see the layers). In QGIS it also connects with service but when I choose add ...
7
votes
3answers
918 views

How to get a list of adjacent lots to a road in ArcMAP and PostGIS/QGIS?

In the following map, I have: A line / road layer A parcel / lot layer The Task: Find and count the list of lots adjacent to the road with their types (parcel_type is a field in the parcel layer) ...
1
vote
1answer
1k views

psycopg2 error with QGIS 1.5

So I just installed QGIS 1.5 using the windows installer not the osgeo4w one and now any plugins that need access to PostgreSQL databases don't seem to work, they all throw a: "Couldn't import Python ...
4
votes
3answers
3k views

Writing a plugin for QGIS using Python to access PostGIS and write geometries

Sorry about the strange title, I didn't really know how to word it. I currently use MapInfo to do most of my GIS work however I have recently installed PostGIS 1.5 and I really like it so far. A ...
65
votes
5answers
45k views

Building effective heat-maps?

Using ArcGIS, QGIS, Grass, and/or GVSIG: What are some of the tools and processes involved in building effective heat maps? What are the plugins involved? What are the major data requirements? What ...
13
votes
4answers
9k views

Is it possible to connect to ArcSDE using QGIS?

Is anyone aware of any plugins, or any other way to connect and view data from an ArcSDE database in QGIS desktop?

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