ATAN2D

 ATAN2D (real-number, real-number)

 Class:  Elemental function - Generic

 Returns the arc tangent of the quotient of the two arguments in
 degrees.

 If both arguments are zero, the result is undefined.  If the first
 argument is positive, the result is positive.  If the first
 argument is negative, the result is negative.  If the first
 argument is zero, the result is zero.  If the second argument is
 zero, the absolute value of the result is 90 degrees.  The value of
 the argument must be greater than zero.

 The range of the result is -180 degrees < result <= 180 degrees.

 +------+---------+----------+------------+-------------+        
 | Args | Generic | Specific |  Argument  | Result Type |
 +------+---------+----------+------------+-------------+
 |   2  | ATAN2D  | ATAN2D   | REAL*4     | REAL*4      |
 |      |         | DATAN2D  | REAL*8     | REAL*8      |
 |      |         | QATAN2D  | REAL*16    | REAL*16     |
 +------+---------+----------+------------+-------------+