HP41: accuracy of 13-digit routines

[Ángel Martin]

(09-02-2015 11:19 AM)Michael Fehlhammer Wrote:  [The only reason why the 41C uses 13 digits internally ( although registers can store 10 digits only ) is to provide 10 digit precision for the results of the more complex functions; due to the used algorithms and error propagation you need these extra 3 digits. Therefore you should not assume that results of log, sin etc. yield more than 10 correct digits.

Yep, and even if they were how would you output it using just the standard X-register approach? Of course HP could have added "double precision" routines like the 16C does for the division and multiplication - where the output would use two stack registers, logically X- and Y- but that's a different story...

ÁM