image                 package:arules                 R Documentation

_V_i_s_u_a_l _I_n_s_p_e_c_t_i_o_n _o_f _B_i_n_a_r_y _I_n_c_i_d_e_n_c_e _M_a_t_r_i_c_e_s

_D_e_s_c_r_i_p_t_i_o_n:

     Provides the S4 methods 'image' to generate level plots to
     visually inspect binary incidence matrices, i.e., objects based on
     'itemMatrix' (e.g., transactions, tidLists, items in itemsets or
     rhs/lhs in rules).  These plots can be used to identify problems
     in a data set (e.g., recording problems with some transactions
     containing all items).

_U_s_a_g_e:

     ## S4 method for signature 'itemMatrix':
     image(x, 
         xlab = "Items (Columns)",
         ylab = "Elements (Rows)", ...)

     ## S4 method for signature 'transactions':
     image(x, ...)

     ## S4 method for signature 'tidLists':
     image(x,
         xlab="Transactions (Columns)",
         ylab="Items/itemsets (Rows)", ...)

_A_r_g_u_m_e_n_t_s:

       x: the object ('itemMatrix', 'transactions' or  'tidLists'). 

xlab, ylab: labels for the plot.

     ...: further arguments passed on to 'image' in  package 'Matrix'
          which in turn are passed on to 'levelplot' in 'lattice'.

_S_e_e _A_l_s_o:

     'image' (for 'dgTMatrix' in 'Matrix'), 'levelplot' (in 'lattice'),
     'itemMatrix-class', 'transactions-class', 'tidLists-class'

_E_x_a_m_p_l_e_s:

     data("Epub")

     ## in this data set we can see that not all
     ## items were available from the beginning.
     image(Epub[1:1000])

