_R_e_a_l _V_e_c_t_o_r_s
	
	     real(n=0)
	     as.real(x)
	     is.real(x)
	
	_D_e_s_c_r_i_p_t_i_o_n:
	
	     real creates a double precision vector of the specified
	     length.  Each element of the vector is equal to 0.
	
	     as.real attempts to coerce its argument to be of real
	     type.
	
	     is.real returns TRUE or FALSE depending on whether its
	     argument is of real type or not.
	
	_N_o_t_e:
	
	     R has no single precision data type.  All real numbers
	     are stored in double precision format.