[Talk-GB] OS grid positions

[Tom Hughes]

On 09/05/11 11:44, ael wrote:

> I have been encouraging a friend to use OSM. He has just mailed in
> puzzlement after trying to find an OS grid reference (presumably
> looking at mapnik).

What do you mean by "find" exactly? Do you mean that he typed it into
the search box on http://www.openstreetmap.org/ and was distressed not
to get a response?

> I saw http://help.openstreetmap.org/questions/2056/using-the-ordnance-survey-national-grid-with-openstreetmap
> but just converting a single grid reference to a good approximation to
> (lat,long) isn't *that* difficult, surely? My Garmin does it a less than
> a ms or so with very low computing power.

Does anything in that thread say it is hard? I don't think it does.

Note that the thread is actually talking about overlaying the grid
rather than just searching for a reference, which is somewhat harder and
would produce what might be a somewhat unexpected result in that the
grid squares wouldn't actually appear to be square.

On top of that overlaying the grid is not something that we would ever
be likely to do on the main site because it a very country specific
thing and the map there is a worldwide one.

Making search work is a whole different issue and I would certainly
consider reasonable patches to do that - there are complicated issues of
OS intellectual property (which I'm not sure Richard's answer on that
thread accurately addresses) which would need to be considered depending
on what algorithm was used.

Tom

-- 
Tom Hughes (tom at compton.nu)
http://compton.nu/