(HP-67/97) Planetary Ephemeris

[Thomas Klemm]

(09-20-2015 08:53 PM)Dieter Wrote:  Could you take a look at line 101? The code there is...

Code:

 97 1
 98 RCL (i)
 99 FRAC
100 STO 3
101 -
102 1
103 RCL 3
104 -
105 /

This calculates (1–R3)/(1–R3) which is always 1. ;-)
I think line 101 should read "+".

It appears that these lines calculate \(\frac{1+e}{1-e}\) of the formula in the mentioned article.

Quote:I also assume that "lbl A", "lbl B", "lbl C" and "lbl D" in the user instructions (table 3) are supposed to mean simply "A", "B", "C" and "D".
Typing a label instruction in run mode does not do anything. ;-)

Finally there are some "TF" commands. This was a HP65 instruction. On the HP67/97 testing flags is done with the "F?" command. I hope the program considers the 67/97's special behaviour of Flag 2 tests. ;-)

I haven't tested this program. But Paul Lutus mentioned that there were errors both in the listing and the data:

Quote:As with the solar position program, the article's publication created a lot of correspondence, including inquiries from JPL and its consultants asking about mathematical details and correcting some errors in the original published data tables (example).

It would be cool if we could make this program run correctly.

Cheers
Thomas