tidList-class             package:arules             R Documentation

_C_l_a_s_s "_t_i_d_L_i_s_t" - _A _T_r_a_n_s_a_c_t_i_o_n _I_D _L_i_s_t

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

     The 'tidList' class is used by the 'itemsets' class to store the
     IDs of the transaction which support each mined itemsets.  Only
     the implementation of the Eclat mining algorithm produces
     transaction IDs. 'tidList' uses the 'itemMatrix' class to
     efficiently store the transaction ID lists as a sparse matrix.

_O_b_j_e_c_t_s _f_r_o_m _t_h_e _C_l_a_s_s:

     Objects are created by Eclat if the 'eclat' function is called
     with 'tidList = TRUE' in the 'ECparameter' object. Objects can
     also be created by calls of the form 'new("tidList", ...)'.

_S_l_o_t_s:

     '_d_a_t_a': object of class 'dgCMatrix' (see 'itemMatrix')

     '_i_t_e_m_I_n_f_o': object of class '"data.frame"' always an empty
          data.frame for transaction ID lists.

     '_t_r_a_n_s_a_c_t_i_o_n_I_n_f_o': object of class '"data.frame"'  with vectors of
          the same length as the number of transactions.  Each vector
          can hold additional information e.g., store transaction IDs
          or user IDs for each transaction.

_M_e_t_h_o_d_s:

[ 'signature(x = "tidList")'; extracts parts (transaction ID vectors)
     from the tidList.  The argument selects the item or itemset.

_c_o_e_r_c_e 'signature(from = "tidList", to = "dgCMatrix")'; access the
     sparse matrix representation. In the 'dgCMatrix' each column
     represents the transaction IDs for one item/itemset.

_c_o_e_r_c_e 'signature(from = "tidList", to = "list")'

_c_o_e_r_c_e 'signature(from = "tidList", to = "matrix")'

_c_o_e_r_c_e 'signature(from = "tidList", to = "transactions")'

_c_o_e_r_c_e 'signature(from = "transactions", to = "tidList")'

_d_e_c_o_d_e 'signature(x = "tidList")'; decodes the numeric transaction
     codes (column numbers in the tidList) given in argument 'tids' to
     the transaction IDs stored in 'x'.  'tids' can be a vector or
     list.

_l_a_b_e_l_s 'signature(x = "transactions")'; returns the labels (item labels
     and transaction IDs) for the incidence matrix as a list of two
     vectors named 'items' and 'transactionIDs'.

_t_r_a_n_s_a_c_t_i_o_n_I_n_f_o 'signature(x = "transactions")': returns
     transactionInfo

_s_h_o_w 'signature(object = "tidList")'

_s_u_m_m_a_r_y 'signature(object = "tidList")'

_A_u_t_h_o_r(_s):

     Michael Hahsler

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

     'eclat', 'itemsets-class'

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

     ## Create transaction data set.
     data <- list(
       c("a","b","c"),
       c("a","b"),
       c("a","b","d"),
       c("b","e"),
       c("b","c","e"),
       c("a","d","e"),
       c("a","c"),
       c("a","b","d"),
       c("c","e"),
       c("a","b","d","e"),
       )
     t <- as(data, "transactions")

     ## Mine itemsets with tidList.
     f <- eclat(data, parameter = list(support = 0, tidList = TRUE))

     ## Get dimensions of the tidList.
     dim(tidList(f))

     ## Coerce tidList to list.
     as(tidList(f), "list")

