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Subject: Re: [Boost-users] [test] CLOSE and CLOSE_FRACTION tolerance
From: Gennadiy Rozental (rogeeff_at_[hidden])
Date: 2011-06-03 01:55:11

Edward Diener <eldiener <at>> writes:

> I am trying to understand the tolerance value passed as the last
> parameter to the BOOST_XXX_CLOSE and BOOST_XXX_CLOSE_FRACTION macros.
> The doc says that for the former the value is percentage units while for
> the latter it is the fraction of absolute values being compared. But in
> each case there are two values, not just one. Which of the two values
> are used to determine the tolerance amount in each case ? If both values
> are being used in each case, how is the tolerance amount computed from
> the tolerance value passed ?

These are using strict check:

|a-b|/|a| < tolerance
|a-b|/|b| < tolerance

You can get weak check if you want (or instead of and above) by using
close_at_tolerance predicate directly.


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