Browse Linux man pages by name. Choose the first letter of the name of the Linux command, function, or file you are interested in:
NAME
atan2, atan2f, atan2l - arc tangent function of two variables
SYNOPSIS
#include <math.h>
double atan2(double y , double x );
float atan2f(float y , float x );
long double atan2l(long double y , long double x );
Link with -lm.
DESCRIPTION
The atan2 () function calculates the arc tangent of
the two variables x and y. It is
similar to calculating the arc tangent of y / x, except
that the signs of both arguments are used to determine the quadrant of the result.
RETURN VALUE
The atan2 () function returns the result in radians,
which is between -PI and PI (inclusive).
CONFORMING TO
SVr4, POSIX.1-2001, 4.3BSD, C89. The float and
long double variants are C99 requirements.
SEE ALSO
acos (3) asin (3)
atan (3) cos (3) sin (3) tan (3)
