[WP-34S] DEG and RAD - diffs

[Paul Dale]

(06-06-2014 04:24 PM)Claudio L. Wrote:  You can indeed achieve convergence by repeating rotations with the same angle. But it's bad for speed!

If you want speed on a modern CPU, don't use CORDIC. Multiplications and additions are similar speed on the 34S -- software floating point is slow but hardware integer operations help a lot.

If I were chasing speed, I'd likely use polynomial or rational approximations. Probably piecewise ones. This will result in larger code sizes. The Intel decimal library recently discussed here did exactly this. Lots of approximations over small intervals meant lots of tables of coefficients but the code is fast and accurate.

Of course, there are other options available. Elementary Functions by Jean-Michel Muller is a good book giving details of many method.


- Pauli