ATAN(3F)                             SysV                             ATAN(3F)



NAME
     atan, datan - FORTRAN arctangent intrinsic function

SYNOPSIS
     real r1, r2
     double precision dp1, dp2

     r2 = atan(r1)

     dp2 = datan(dp1)
     dp2 = atan(dp1)

DESCRIPTION
     atan returns the real arctangent of its real argument.  datan returns the
     double-precision arctangent of its double-precision argument.  The
     generic form atan may be used with a double-precision argument returning
     a double-precision value.

SEE ALSO
     trig(3M).