atan function
| Input type | Output type | 
| float complex | float complex | 
This function calculates the arctangent of the argument and returns the result. If the argument is of type int, it is first converted to float by the compiler.
Examples:
atan(1) ; 0.7854 atan(1.0) ; 0.7854 atan((1,0)) ; (0.7854, 0)
Note: atan(tan(x)) is equal to x if x is within the range -pi..pi.
See Also
 atan2 function
 tan function
 tanh function
 atanh function