<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">Good evening,<br class=""><div><br class=""><blockquote type="cite" class=""><div class="">On 4. Jun 2022, at 22:38, Dirk Hohndel <<a href="mailto:dirk@hohndel.org" class="">dirk@hohndel.org</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><span style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">Yes. Negative time makes me twitchy...</span><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><blockquote type="cite" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; text-decoration: none;" class="">And yes, the reason 'FRACTION()' does that explicit unsigned thing is<br class="">because negative values don't have sane well-defined behavior wrt<br class="">division and modulus in C (ie the division rounding towards zero will<br class="">then cause a negative fractional value).<br class=""><br class="">Your SIGNED_FRACTION() avoids that problem, but it does seem a bit<br class="">questionable to ever show negative values in things that want<br class="">fractions (which are generally physical units: time, depth, things<br class="">like that).<br class=""></blockquote><br style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;" class=""><span style="caret-color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;" class="">I think I have to agree with that. This is mathematically sane, but I question the practicality…</span></div></blockquote></div><div class=""><br class=""></div>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.<div class=""><br class=""></div><div class="">Best</div><div class="">Robert<br class=""><div class=""><br class=""></div></div></body></html>