long double
_ctansl(long double complex z)
{
long double f, x, x2, y, y2, rn, t;
long double d;
x = fabsl(2.0L * creall(z));
y = fabsl(2.0L * cimagl(z));
x = _redupil(x);
x = x * x;
y = y * y;
x2 = 1.0;
y2 = 1.0;
f = 1.0;
rn = 0.0;
d = 0.0;
do {
rn += 1.0L;
f *= rn;
rn += 1.0L;
f *= rn;
x2 *= x;
y2 *= y;
t = y2 + x2;
t /= f;
d += t;
rn += 1.0L;
f *= rn;
rn += 1.0L;
f *= rn;
x2 *= x;
y2 *= y;
t = y2 - x2;
t /= f;
d += t;
} while (fabsl(t/d) > MACHEPL);
return d;
}
long double complex
catanl(long double complex z)
{
long double complex w;
long double a, t, x, x2, y;
x = creall(z);
y = cimagl(z);
if ((x == 0.0L) && (y > 1.0L))
goto ovrf;
x2 = x * x;
a = 1.0L - x2 - (y * y);
if (a == 0.0)
goto ovrf;
t = 0.5L * atan2l(2.0L * x, a);
w = _redupil(t);
t = y - 1.0L;
a = x2 + (t * t);
if (a == 0.0L)
goto ovrf;
t = y + 1.0L;
a = (x2 + (t * t))/a;
w = w + (0.25L * logl(a)) * I;
return w;
ovrf:
#if 0
mtherr ("catanl", OVERFLOW);
#endif
w = HUGE_VALL + HUGE_VALL * I;
return w;
}
