WP 34S vs. DM42 decimal128 differences?

[Paul Dale]

(03-30-2018 04:44 PM)Nigel (UK) Wrote:  \In the WP34S source code \(2\pi\) is already present as a constant to 450 decimal places (or thereabouts). So why not use it to get double precision answers for trig functions of double precision arguments?

The many decimals are required to get accurate answers in single precision. E.g. try \(sin(10^{100})\). To get the same for double precision requires thousands of digits -- I'd guess about 8500 give or take. Making double precision trigonometric functions accurate across their entire range isn't feasible on the hardware, there isn't enough memory.

Still, you made a good argument for improving them where they are more typically used. I'll have to think it through in more detail. I'll also have to work out the worst case memory usage for functions that can call sine or cosine to see if the extra space required will fit. Were a few bytes from not fitting the stack in.


Pauli