4.15 acos - Inverse Cosine (arccosine)

Format: acos( $num$ )

Compute arccosine (inverse cosine). The function evaluates the principal value ranges of $-1.0\sim 1.0$ , and returns values within the parameter of $0.0\sim \pi$ .

Example

Example 1: Basic Example

$ more dat1.csv
id,val
1,-1.0
2,0
3,1.0
4,
5,2
$ mcal c='acos(${val})' a=rsl i=dat1.csv o=rsl1.csv
#END# kgcal a=rsl c=acos(${val}) i=dat1.csv o=rsl1.csv
$ more rsl1.csv
id,val,rsl
1,-1.0,3.141592654
2,0,1.570796327
3,1.0,0
4,,
5,2,