ACOS Function
Returns the arccosine of x.
enabled.Usage
result = ACOS(x)
Input Parameters
x—The cosine of the desired angle. Cannot be of a complex data type and must be in the range –1 ≤ x ≤ 1.
Returned Value
result—Arccosine of x.
Keywords
None.
Discussion
The inverse cosine function, or arccosine, denoted by cos –1, is defined by:
y = cos –1x
if and only if:
cos y = x
where:
–1 ≤ x ≤ 1 and 0 ≤ y ≤ π
The parameter x can be an array, with the result having the same data type where each element contains the arccosine of the corresponding element from x.
When x is of double-precision floating-point data type, the result is of the same type. All other data types are converted to single-precision floating-point and yield a floating-point result. The result is an angle, expressed in radians, whose cosine is x.
Values generated by ACOS range between 0 and π.
Example
x = ACOS(1)
PRINT, x
; PV-WAVE prints: 0
