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Subject: Re: [boost] GGL Review
From: Paul A. Bristow (pbristow_at_[hidden])
Date: 2009-11-17 06:03:37

> -----Original Message-----
> From: boost-bounces_at_[hidden] [mailto:boost-bounces_at_[hidden]] On
Behalf Of
> Phil Endecott
> Sent: Monday, November 16, 2009 5:35 PM
> To: boost_at_[hidden]
> Subject: Re: [boost] GGL Review

is indeed thought-provoking.
> Personally, I find it better to use fixed point (e.g. for
> latitude/longitude) and relax knowing that I don't have to worry.

But isn't this assuming that your latitude/longitude (or whatever) is exact?

Although the latitude/longitude values you are using obviously are 'exact',
there is always an uncertainty about the real-life position.

If you can't tell the algorithm what this (not-zero) uncertainty is, you can't
expect an exact answer.

Is this why one group of users accepts that his input is uncertain and accepts
(slightly) uncertain result,

but others (like you and Luke) assert your input is exact and demand an exact


Paul A. Bristow
Prizet Farmhouse
Kendal, UK   LA8 8AB
+44 1539 561830, mobile +44 7714330204

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