<html>
<head>
<meta content="text/html; charset=utf-8" http-equiv="Content-Type">
</head>
<body bgcolor="#FFFFFF" text="#000000">
<p>Hi Robert, hi Rick, hi All,<br>
</p>
<br>
<div class="moz-cite-prefix">Am 15.02.2017 um 02:23 schrieb Rick
Walsh:<br>
</div>
<blockquote
cite="mid:CAF+v9JuVuHmrGMaSnQGPfxMx9NpkX6pou2i3HYNdb2b15o+EhA@mail.gmail.com"
type="cite">
<div dir="ltr">On 15 February 2017 at 06:50, Stefan Fuchs <span
dir="ltr"><<a moz-do-not-send="true" target="_blank"
href="mailto:sfuchs@gmx.de">sfuchs@gmx.de</a>></span>
wrote:<br>
<div class="gmail_extra">
<div class="gmail_quote">
<blockquote style="margin:0px 0px 0px 0.8ex;border-left:1px
solid rgb(204,204,204);padding-left:1ex"
class="gmail_quote">
<div bgcolor="#FFFFFF">
<p>Hi All,</p>
<p>Joachim (R.) and I finished our first basic version
of the minimum gas calculation for the planner.<br>
We are now looking for testing and feedback :-)<br>
</p>
</div>
</blockquote>
<div>Great work on tackling this. It's really good to see
new ideas and new developers contributing to the code. I
will test when I get a chance, which unfortunately won't
be for a few days. In the meantime, I have a few
comments/suggestions.<br>
</div>
</div>
</div>
</div>
</blockquote>
Thanks! Despite the fact that I still have to learn a lot this is
really fun :-)<br>
<br>
<blockquote
cite="mid:CAF+v9JuVuHmrGMaSnQGPfxMx9NpkX6pou2i3HYNdb2b15o+EhA@mail.gmail.com"
type="cite">
<div dir="ltr">
<div class="gmail_extra">
<div class="gmail_quote">
<blockquote style="margin:0px 0px 0px 0.8ex;border-left:1px
solid rgb(204,204,204);padding-left:1ex"
class="gmail_quote">
<div bgcolor="#FFFFFF">
<p> More details below...<br>
</p>
<p>Link to initial idea and discussion:<br>
<a moz-do-not-send="true" target="_blank"
href="https://github.com/Subsurface-divelog/subsurface/issues/188"
class="gmail-m_8098681307314788349moz-txt-link-freetext">https://github.com/Subsurface-<wbr>divelog/subsurface/issues/188</a><br>
</p>
<p>Link to feature branch on Github:<br>
<a moz-do-not-send="true" target="_blank"
href="https://github.com/sfuchs79/subsurface/tree/feature_minimum_gas"
class="gmail-m_8098681307314788349moz-txt-link-freetext">https://github.com/sfuchs79/<wbr>subsurface/tree/feature_<wbr>minimum_gas</a></p>
<p><br>
</p>
<p>My feedback to comments from Robert and Joachim (B.):<br>
[...]<br>
- Support rec dives: Yes, clearly, calculation is
active for all OC dives. I put some limitations for
min depth (>18m) and min tank size (12l).
Calculating minimum gas for smaller cylinders is from
my point of view almost useless.<br>
</p>
</div>
</blockquote>
<div>I don't see the reason for limiting tank size and
depth. 10.5l steel cylinders are pretty common where I
dive, and AL80 (11.1l) cylinders are the most common in
warm water. Also there are smaller 300bar cylinders
popular in some areas. Minimum gas is also relevant for
bailout cylinders, and some people use AL40 (5.6l) for
them (although we don't do any automatic bailout
calculations). Surely having sufficient gas is just as
important a consideration for small cylinders.<br>
</div>
</div>
</div>
</div>
</blockquote>
Ok, agreed. Let's remove this limit completely.<br>
I at the beginning was unhappy that my implementation was also
showing such results like "your minimum gas is 537bar" if you select
a small cylinder ;-)<br>
But I meanwhile avoid this with the simple check of minimum gas
result against the starting pressure of the cylinder and print a
warning instead of any result then. One may say this is also still
not perfect but for me at the moment it's good enough.<br>
<br>
<blockquote
cite="mid:CAF+v9JuVuHmrGMaSnQGPfxMx9NpkX6pou2i3HYNdb2b15o+EhA@mail.gmail.com"
type="cite">
<div dir="ltr">
<div class="gmail_extra">
<div class="gmail_quote">
<div>I agree minimum gas is usually less of a concern for
shallow dives, but spend an hour or more at 18m on air
without a deco cylinder and you will require a significant
amount of gas to allow two divers to surface safely. Do
we gain anything by excluding this possibility?<br>
</div>
</div>
</div>
</div>
</blockquote>
Hmm.. maybe 18m is really not a good decision. It's really arbitrary
as Robert is saying. What I would like to avoid is that we are
printing a minimum gas result in case we replan a dive and the
calculated planner points including all deco stops are still in the
user entry table (before one deletes them). <br>
May I propose a compromise here: Lets use last/2nd last deco stop
depth (at ~6m) as limit. This is much less arbitrary than choosing
18m.<br>
<br>
<blockquote
cite="mid:CAF+v9JuVuHmrGMaSnQGPfxMx9NpkX6pou2i3HYNdb2b15o+EhA@mail.gmail.com"
type="cite">
<div dir="ltr">
<div class="gmail_extra">
<div class="gmail_quote"><br>
<div>Robert mentioned this his comments, so sorry to repeat,
but where possible try to use the special unit types
defined in core/dive.h: duration_t (unit seconds), depth_t
(unit mm), <span class="gmail-pl-c1">pressure_t (unit
mbar), </span><span class="gmail-pl-c1">volume_t (unit
ml). It's a little bit of extra work, but it makes the
code clearer to read and debug. Obviously the UI should
present the values in friendly units.<br>
</span></div>
</div>
</div>
</div>
</blockquote>
For this and all the other comments from Robert I hope I understood
everything and there is nothing to discuss. Updated version will
come soon.<br>
BTW: The types are in units.h ;-)<br>
A very important hint came from Robert about why we add the two new
variables to struct diveplan. This was clearly a mistake is not
needed. I will remove it.<br>
<br>
<br>
Best regards<br>
Stefan<br>
<br>
<br>
<div class="moz-signature">-- <br>
<meta http-equiv="CONTENT-TYPE" content="text/html; charset=utf-8">
<title></title>
<meta name="GENERATOR" content="OpenOffice.org 3.3 (Win32)">
<meta name="CREATED" content="0;0">
<meta name="CHANGEDBY" content="Stefan Fuchs">
<meta name="CHANGED" content="20120503;23115492">
<style type="text/css">
<!--
P { color: #000000 }
-->
</style>
<p>Stefan Fuchs<br>
E-Mail: <a href="mailto:sfuchs@gmx.de">sfuchs@gmx.de</a></p>
</div>
</body>
</html>