math.atan
Available inall subroutines.
Computes the principal value of the arc tangent of its argument x
.
Parameters
x
- Floating point value.
Return Value
Upon successful completion, this function returns the arc tangent of x
in the
range -math.PI_2
to
math.PI_2
radians inclusive.
If x
is math.NAN
, a NaN will be returned.
If x
is ±0, x
will be returned.
If x
is math.POS_INFINITY
or math.NEG_INFINITY
,
±math.PI_2
will be returned.
If x
is subnormal, a range error occurs and x
will be returned.
Errors
If the x
argument is subnormal, then fastly.error
will be set to ERANGE
.
Example
declare local var.fo FLOAT;
set var.fo = math.atan(1);