logique                package:multiv                R Documentation

_L_o_g_i_c_a_l _C_o_d_i_n_g

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

     Simple logical coding of a vector: each value in the  vector is
     replaced by a 1 (if it is above or equal to the median), by a 0
     (if it is below the median).

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

     logique(a)

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

       a: real-valued vector, with no missing values. 

_V_a_l_u_e:

     matrix of `length(a)' rows, and two columns.  The first column
     contains the logically coded values of `a', and the second column
     contains their  complements.  Hence each row of this returned
     matrix necessarily sums to 1.

_B_a_c_k_g_r_o_u_n_d:

     This form of coding is suitable for a subsequent correspondence
     analysis. When all variable have been logically (or fuzzily)
     coded, the row masses  (proportional to the row sums) are
     identical.  Logical coding results in the input being in complete
     disjunctive form.

_R_e_f_e_r_e_n_c_e_s:

     J.-P. Benzecri Correspondence Analysis Handbook Marcel Dekker,
     Basel, 1992.

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

     `flou', `ca', `supplr', `supplc'.

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

     data(USArrests)
     USArrests <- as.matrix(USArrests)
     # Fuzzy coding of input variables
     a.log <- logique(USArrests[,1])
     b.log <- logique(USArrests[,2])
     c.log <- logique(USArrests[,3])
     d.log <- logique(USArrests[,4])
     newdata <- cbind(a.log, b.log, c.log, d.log)
     ca.newdata <- ca(newdata)

