NAME
catan, catanf,
catanl —
complex circular arc tangent
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(),
catanf()
and
catanl()
functions compute the complex circular arc tangent of
z.
If z = x + iy, then
Re catan(z) = 1/2 * atan(2x / (1 - x^2 - y^2)) + k Pi. Im catan(z) = 1/4 * log((x^2 + (y + 1)^2) / (x^2 + (y - 1)^2)).
RETURN VALUES
The catan(),
catanf() and catanl()
functions return the complex circular arc tangent of z
with unbounded imaginary part, and real part in the interval [-Pi/2,
Pi/2].
SEE ALSO
STANDARDS
The catan(),
catanf() and catanl()
functions conform to ISO/IEC 9899:1999
(“ISO C99”).