NAME
	IEEEDPAtan -- compute the arctangent of a floating point number

   SYNOPSIS
	  x   = IEEEDPAtan(  y  );
	d0/d1		   d0/d1

	double	x,y;

   FUNCTION
	Compute arctangent of y in IEEE double precision

   INPUTS
	y - IEEE double precision floating point value

   RESULT
	x - IEEE double precision floating point value

   BUGS

   SEE ALSO
	IEEEDPTan(), IEEEDPAsin(), IEEEDPACos()