On: Implementing the Exponential Function

[olliej]

Ugh I had to implement all the transcendental functions a while ago. It was miserable, especially dealing with intermediate rounding, etc

I don’t recommend it.

That said I liked that there’s a specific exp-1 function (otherwise you drop most precision).

[mjcohen → olliej]

To go with that, you need ln(1+x). HP calculators had both.

[jjgreen → mjcohen]

As has C (since C99)

http://www.cplusplus.com/reference/cmath/log1p/

[olliej → mjcohen]

I believe that they're all part of the IEEE 754 spec, but some of these functions are just recommended.

x87 has pretty much all of them, including two remainder implementations \o/

[olliej → mjcohen]

I did implement that, and sqrt, etc. With integer math because the misery of needing more precision :D (or is that :( ? )