4.20 atan - Inverse Tangent

Format: atan( $num$ )

Compute arctangent (inverse tangent). The function evaluates the principal value ranges from $-\infty \sim \infty$ , and returns values within the parameter of $-\pi /2 \sim \pi /2$ .

Examples

Example 1: Basic Example

$ more dat1.csv
id,val
1,-1.0
2,0
3,1.0
4,
5,1.0e+10
$ mcal c='atan(${val})' a=rsl i=dat1.csv o=rsl1.csv
#END# kgcal a=rsl c=atan(${val}) i=dat1.csv o=rsl1.csv
$ more rsl1.csv
id,val,rsl
1,-1.0,-0.7853981634
2,0,0
3,1.0,0.7853981634
4,,
5,1.0e+10,1.570796327