>>>>> "willisb" == willisb <willisb@unk.edu> writes:
willisb> The value of eps in trigi.lisp is too small -- this gives poor numerical
willisb> accuracy for some trigonometric functions. An example
willisb> /* Homebrew acosh function. */
willisb> (C1) xacosh(x) := log(x + sqrt(x * x - 1))$
willisb> (C2) xacosh(4100.0d0);
willisb> (D2) 9.011889418380244
willisb> (C3) acosh(4100.0d0);
willisb> (D3) 9.011889433252344
willisb> (C4)
willisb> Each digit of xacosh(4100.0d0) is correct. [I choose 4100.0 because it
willisb> just exceeds 1 / sqrt(eps).]
[snip]
willisb> alternatively, we could turn the numerical work over to Lisp. For example
I believe this is the correct solution.
Ray