ATAN(3) | Library Functions Manual | ATAN(3) |
atan
— arc tangent
function of one variable
#include
<math.h>
double
atan
(double
x);
long double
atanl
(long
double x);
float
atanf
(float
x);
The
atan
()
function computes the principal value of the arc tangent of
x. The result is in the range
[-pi/2, +pi/2].
atan
(±0)
returns ±0.
atan
(±infinity)
returns ±pi/2
If you need to apply the atan
() function
to SIMD vectors or arrays, using the following functions provided by the
Accelerate.framework may give significantly better performance:
#include
<Accelerate/Accelerate.h>
vFloat
vatanf
(vFloat
x);
void
vvatanf
(float
*y, const float *x, const int
*n);
void
vvatan
(double
*y, const double *x, const int
*n);
acos(3),
asin(3),
atan2(3),
cos(3),
cosh(3),
sin(3),
sinh(3),
tan(3),
tanh(3),
math(3) The
atan
() function conforms to ISO/IEC 9899:2011.
December 11, 2006 | macOS 14.6 |