NavList:

Ken,

Thanks for your interesting contribution.

You are right : yes, the method you indicate is one of the usual ones. If we want to go with Chebishev Polynoms for the 4 Nav. Planets, RLB Chebysheev values similar to the ones published by Bureau des Longitudes and earlier mentioned would probably be hard to beat (between 900 and 1100 "figures" for one full year, with the number "-28.20369" counting as/against 8 such "figures"). If Chebishev allowed, then it's all over here....

.. BUT, just for this exercise and given what I could and can best understand of Frank's initial ideas, the methods here-above would probably not be "valid" ones.

I interpreted the "challenge" from Frank as follows : from a data array to be defined as "small" as possible, use only brute force LinInt as a "reason" (or an "excuse") to compute as fast as possible (therefore Chebishev not a valid method here).

With these assumptions, it remains an interesting exercise, and certainly of some earlier "classical sort" which we could have been tasked for solving, many Moons ago by the end of the previous Millenium, although to-day such exercise bears very little if any practical interest.

But, after all, who ever said or even seriously thought that our beloved and cherished Lunars are also day-to-day practical life, anyway ? ...

At the end of the day, I agree with your "nostalgic regrets" when facing this unescapable fact : given the huge data storage available nowadays, we have to face that, even "if too much to bear" , "we can now scrap [even] arithmetic for look-up tables" ...

I suggest that we should wait for Frank's view-point here, since this subject also seems to have caught the attention of at least one other Gentleman of our NavList Member. And if it turns out that the "audience" is really too small on this topic, it can be covered through personal e-mails. Not a problem from my end.

Until we get Frank's reply on all these points, I think it more appropriate for me to stay silent on this subject for the time being.

Best Regards

Antoine M. "Kermit" Couëtte

----------------------------------------------------------------
NavList message boards and member settings: www.fer3.com/NavList
Members may optionally receive posts by email.
To cancel email delivery, send a message to NoMail[at]fer3.com
----------------------------------------------------------------