HP 3000 Manuals

HP COBOL II/XL Reference Manual

ATAN Function 

The ATAN function returns the arctangent of the parameter.  The function
type is numeric.

Syntax 

     FUNCTION ATAN (parameter-1)

Parameters 

parameter-1           Must be class numeric.

Return Value 

The value returned is the approximation of the arctangent of parameter-1 
and is between -pi/2 and pi/2, inclusive.  The return value is a numeric
value in radians.

Example 

     77  TAN-OF-ANGLE       PIC S9(5)V9(5)  VALUE +00000.99998.
     77  ANGLE-RADIANS      PIC S99V9(5) VALUE ZERO.
             :
     COMPUTE ANGLE-RADIANS = FUNCTION ATAN (TAN-OF-ANGLE).
     DISPLAY TAN-OF-ANGLE.
     DISPLAY ANGLE-RADIANS.

The above example displays the following:

     +00000.99998
     +00.78538

MPE/iX 5.0 Documentation