At 02:22 PM 7/7/2003, Rozental, Gennadiy wrote:

>I could probably prohibit usage of CHECK_CLOSE with number of rounding
>errors provided.
>Is there any other general recommendations how to choose the tolerance to


>FP computation correctness checking?

There has been some recent discussion on comp.lang.c++.moderated, subject "equality of two doubles". The last post was from Andrei Alexandrescu:

>What's most of the time needed is relative precision.
>
>So, numerical gurus: how can one express "a equals b within 0.1%" over
>the whole range of floating point numbers? If that can be done, it would
>be a nice useful routine.
>
>bool approximately_equal(double lhs, double rhs, double relative_prec)
>{
>    // fill in here please :o)
>}

But it really doesn't seem that a test library is the right home for such functions. I think all the fp stuff should be removed from Boost.Test, and passed on as a challenge to the numerics experts.

After all, the user can always write:

BOOST_CHECK( approximately_equal(...) );

--Beman

_______________________________________________
Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost

Reply via email to