catan(3) — Linux manual pages

Linux manual pages	Section 3

Name

catan, catanf, catanl — complex arc tangents

Synopsis

#include <complex.h>

double complex catan( double complex z);

float complex catanf( float complex z);

long double complex catanl( long double complex z);

	Note
	Link with `−lm`.

DESCRIPTION

The catan() function calculates the complex arc tangent of z. 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))

VERSIONS

These functions first appeared in glibc in version 2.1.

CONFORMING TO

C99.

COLOPHON

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