Calculate large factorials on a HP48 (SysRPL)

[Christoph Giesselink]

(02-19-2014 10:45 AM)Werner Wrote:  For both accuracy and speed, however, you'd be better off dividing by LN(10) only once, after the loop?

I agree with the speed reason, but when I wrote the program years ago I got better results adding the LOG instead of the LN numbers.

But your suggested modification is simple for own tests:

Code:

...
  #1+_ONE_DO (DO)
      INDEX@ UNCOERCE%%                 ( convert loop counter to long real )
      %%LN                                                 ( %%LN of number )
      %%+                                                       ( to result )
    LOOP
    OVER %%/                               ( convert result to sum of %%LOG )
    DUP %%FLOOR                                            ( fetch exponent )
...

Christoph