[WP34s] Regularized incomplete Beta function

[Paul Dale]

(05-04-2014 05:26 PM)Dieter Wrote:  ... 24 (!) digits right. Either the internal tangent function is not that accurate or the current implementation does not evaluate the quantile as 1/tan(1E–10*180°) which would yield a nearly perfect result. ;-)

The one df case is implemented as tan(pi(x-1/2)) which loses digits in cases like these. I missed the transformation to -cot(pi x) when I implemented this I'm pretty sure TAN is up to the task.

More usefully, your QF implementation isn't much longer than the current one and it avoids the generic solver. I might see if I can substitute it on the 34S too. It isn't all that straightforward because several functions you use are implemented in XROM and can be used directly. Rather, they have to be called using XEQ and they'll mess the stack up.


- Pauli