_C_r_o_s_s _T_a_b_u_l_a_t_i_o_n
	
	     table(...)
	
	_D_e_s_c_r_i_p_t_i_o_n:
	
	     table uses the cross-classifying factors provided as
	     arguments to build a contingency table of the counts at
	     each combination of factor levels.
	
	_E_x_a_m_p_l_e_s:
	
	     # simple two-way contingency table
	     tab <- table(sex,age)