| Pré. | Proc. |
ccot
Complex circular cotangent.SYNOPSIS:
void ccot();
cmplx z, w;
ccot(&z, &w);
DESCRIPTION:
If
z = x + iy,
then
sin 2x - i sinh 2y
w = --------------------.
cosh 2y - cos 2x
On the real axis, the denominator has zeros at even multiples of PI/2. Near these points it is evaluated by a Taylor series.
ACCURACY:
Relative error:
arithmetic domain # trials peak rms
DEC -10,+10 3000 6.5e-17 1.6e-17
IEEE -10,+10 30000 9.2e-16 1.2e-16
Also tested by ctan * ccot = 1 + i0.