[Talk-GB] Quarterly Project: Addresses and Postcodes

Tom Hughes tom at compton.nu
Thu Oct 19 13:03:40 UTC 2017

On 19/10/17 13:00, Steven Horner wrote:

> UK postcodes generally cover an area/polygon. How big that area is 
> appears to come down to how much mail that area is likely to receive, I 
> think that's how its described on Wikipedia. So it could cover one 
> building, a street or a huge area if rural.
> Ordnance Survey sell CodePoint Polygons which is the polygons each 
> postcode covers. Obviously we can't use that.

No, that really isn't true.

There is no defined area or polygon for a post code.

Post codes are defined as a list of delivery points.

Any polygon you see for a postcode has been invented by using some 
algorithm to draw a polygon that happens to encapsulate all those 
delivery points.

Depending on the algorithm that may or may allow for overlapping 
polygons and in general you may get different answer depending on the 
details of the algorithm used.


Tom Hughes (tom at compton.nu)

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