Good evening, > On 4. Jun 2022, at 22:38, Dirk Hohndel <d...@hohndel.org> wrote: > > Yes. Negative time makes me twitchy... > >> And yes, the reason 'FRACTION()' does that explicit unsigned thing is >> because negative values don't have sane well-defined behavior wrt >> division and modulus in C (ie the division rounding towards zero will >> then cause a negative fractional value). >> >> Your SIGNED_FRACTION() avoids that problem, but it does seem a bit >> questionable to ever show negative values in things that want >> fractions (which are generally physical units: time, depth, things >> like that). > > I think I have to agree with that. This is mathematically sane, but I > question the practicality…
please note it’s not negative stop times but negative time differences: In those particular circumstances, you have to do 13 seconds less decompression stops for every minute you further spend at 10m. This totally makes sense to me (I admit it’s a rare situation that deco stops get shorter for extended bottom time) and also displaying the 13 seconds as 0:13 (which is the output of FRACTION or SIGNED_FRAC in that case) seems the natural way to me. Best Robert
signature.asc
Description: Message signed with OpenPGP
_______________________________________________ subsurface mailing list subsurface@subsurface-divelog.org http://lists.subsurface-divelog.org/cgi-bin/mailman/listinfo/subsurface
