Changing Of The Guard

[Thomas Klemm]

(04-22-2014 05:28 AM)Matt Agajanian Wrote:  Thomas, thanks for the verification. Although, as I regard HP in high technological respect, their usage of guard digits in their calcs is quite obscure and I do not recall in any manuals that calculations are carried past 10 digits of accuracy (unless it's explicitely stated in some of their manuals and I must've missed the fine print somwhere).

In HP calculators the guard digits are not exposed to the user. The intermediate result is rounded to 10 or 12 digits. You always get what you see. TI calculators only displayed the rounded result while keeping the guard digits internally. This is an advantage if you chain computations but can be confusing because e.g. you see a 2 but internally it is 1.9999999999. Start squaring this number to see what can happen.

Cheers
Thomas