SYNOPSIS
#include <complex.h> "double complex catan(double complex "z);
"float complex catanf(float complex "z);
"long double complex catanl(long double complex "z);
DESCRIPTION
The catan() function calculates the complex atan(). If y = catan(z), then z = ctan(y). The real part of y is chosen in the interval [-pi/2,pi/2]. One has catan(z) = 1/2i clog((1+iz)/(1-iz)).
"CONFORMING TO"
C99
"SEE ALSO"
clog(3), ccos(3)
