ATAN(III)                    4/30/73                    ATAN(III)
NAME
     atan, atan2 - arc tangent function
SYNOPSIS
     jsr    pc,atan[2]
     double atan(x)
     double x;
     double atan2(x, y)
     double x, y;
DESCRIPTION
     The  atan  entry returns the arc tangent of fr0 in fr0; from
     C, the arc tangent of x is returned.  The range is  -J/2  to
     J/2.   The atan2 entry returns the arc tangent of fr0/fr1 in
     fr0; from C, the arc tangent of x/y is returned.  The  range
     is -J to .
DIAGNOSTIC
     There is no error return.
BUGS
                              - 1 -