[Qgis-user] Public Sector Mapping Agreement

[Andrew Chapman]

I have old sample OS .gz files, but it would be best to use their current
ones. The data SHOULD be available via the "Download our sample data"
section at www.ordnancesurveymastermap.com/ (I can't find a direct link to
files), but it wouldn't work when I tried. I've reported the problem to OS
and am waiting for a human response.
A further source of additional information is the OS XML Schema Respository
www.ordnancesurvey.co.uk/oswebsite/xml/schema/index.html, but I don't know
enough about QGIS to understand how to use these.
I've tried an old sample .gz file with both 1.6 and 1.7. Neither version
supports direct opening of .gz (which would be the simplest way for new
users), but actually open the unzipped .gml files. I have had problems in
the past with older versions of WinZip (e.g. 12.0) where they couldn't unzip
this format correctly, but gzip or other alternatives worked. The latest
WinZip (15.0.) also seems to work, although you have to enter the extension
of the file to expand, as it doesn't know to add .gml.
Unless the latest format has changed, OS uses the 'orientation' attribute
for text angle, but the value seems to be (degrees * 10). The loaded GML
layer doesn't allow editing, so it isn't possible to add a further attribute
calculated from 'orientation'. Saving as a shapefile under 1.6 fails with an
error because, when the longer GML attribute names are trimmed to ten
significant characters, there are duplicate attribute names.

Andrew
________________________________________
From: Noli Sicad [mailto:nsicad at gmail.com] 
Sent: 04 March 2011 05:59
To: Andrew Chapman
Cc: qgis-user at lists.osgeo.org
Subject: Re: [Qgis-user] Public Sector Mapping Agreement

Hi Andrew,

> To encourage take-up for both GIS and QGIS, it may help if there were
> tutorials to take a new user of GIS through the steps to download data
from
> Ordnance Survey (probably only in GZ format for the topology layers).
> To date I've been getting data as shapefiles - when I last tried (an
earlier
> version) QGIS wouldn't load .gz and the support for .gml may have been
> incomplete.
> Is anyone else using Ordnance Survey .gz files directly?
> Would the best advice for users new to GIS be to convert to shapefiles or
> use a database (something I've not yet managed to do)?
> Are there any UK users involved with town or parish councils?

I think it would be wise to put an example of this OS gz file so we
can try if we can open it with QGIS. Just a very simple example of the
file :-).

Then, post the URL where we can  download it.

Noli 
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