On 3 March 2016 at 00:28, Linus Torvalds <[email protected]> wrote: > Lubomir, what tool did you use for the least-square fitting? >
those equations in particular came from this website: http://polynomialregression.drque.net/online.php > Because it would be interesting to see if we can do this for the table at > > http://www.baue.org/library/zfactor_table.php i can take a look a these a bit later - e.g. in 30 minutes. > > and see how reasonable it is to approximate gas mixes by doing the > O2/N2/He calculations and then just "mixing" the compressibility (looking > at the O2 and N2 tables and then the air table, I think a stupid and > straightforward linear mixing is probably _entirely_ unphysical, but not > necessarily too far off). > > For example, looking at 3000 psi, and then just doing > > 0.947*0.21 + 1.054*0.79 > > to do a linear mixing of the O2/N2 values gives you 1.0315, which is quite > close to the actual air compressibility value. > > So I think it might be possible to take those baue.org tables, create > polynomials for them, and then have a simple linear mix for the gases, and > get reaonable approximations for all relevant scuba gases.. > i don't exactly understand the physics here, but in terms of "plotting a data set" and looking at how the graphs / isotherms variate, the linear mix might be a tolerable solution. lubomir -- _______________________________________________ subsurface mailing list [email protected] http://lists.subsurface-divelog.org/cgi-bin/mailman/listinfo/subsurface
