Re: [boost] Boost Test Library: general floating point comparisons

From: Gennadiy Rozental (gennadiy.rozental_at_[hidden])
Date: 2007-02-19 06:05:10

"John Maddock" <john_at_[hidden]> wrote in message 
news:00ab01c7540d$7d100b60$3cef0352_at_fuji...
> Gennadiy Rozental wrote:
>> Ok. How about
>>
>> BOOST_CHECK_PRC_DIFF
>> BOOST_CHECK_REL_DIFF
>> BOOST_CHECK_EPS_DIFF
>>
>> How about
>>
>> BOOST_CHECK_ABS_DIFF
>>
>> for absolute difference comparison?
>
> Oh please no.... too cute and cryptic by half, they're not 
> self-explanatory
> at all.

How about a compromise:

BOOST_CHECK_PERCENT_DIFF
BOOST_CHECK_RELATIVE_DIFF
BOOST_CHECK_EPSILON_DIFF
BOOST_CHECK_ABSOLUTE_DIFF (do we need this one?)

>> What kind of error message would you like for each tool to produce?
>>
>> Here is an example of BOOS_CHECK_CLOSE produce:
>>
>> difference between v1{1.23456e-10} and v2{1.234571e-10} exceeds
>> 0.0001%
>
> Which is fine if the tolerance is expressed as a percent, but not 
> otherwise:
> the error quoted needs to be expressed in the same units as are passed to
> the macro, otherwise you'll just confuse folks again.

So.Would you care to provide a error message body for the non-percent based 
tools?

Gennadiy