m20kcodMAPCOUNTS         package:m20kcod.db         R Documentation

_N_u_m_b_e_r _o_f _m_a_p_p_e_d _k_e_y_s _f_o_r _t_h_e _m_a_p_s _i_n _p_a_c_k_a_g_e _m_2_0_k_c_o_d._d_b

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

     m20kcodMAPCOUNTS provides the "map count" (i.e. the count of
     mapped keys) for each map in package m20kcod.db.

_D_e_t_a_i_l_s:

     This "map count" information is precalculated and stored in the
     package annotation DB. This allows some quality control and is
     used by the 'checkMAPCOUNTS' function defined in AnnotationDbi to
     compare and validate different methods (like 'count.mappedkeys(x)'
     or 'sum(!is.na(as.list(x)))') for getting the "map count" of a
     given map.

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

     'mappedkeys', 'count.mappedkeys', 'checkMAPCOUNTS'

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

       m20kcodMAPCOUNTS
       mapnames <- names(m20kcodMAPCOUNTS)
       m20kcodMAPCOUNTS[mapnames[1]]
       x <- get(mapnames[1])
       sum(!is.na(as.list(x)))
       count.mappedkeys(x)   # much faster!

       ## Check the "map count" of all the maps in package m20kcod.db
       checkMAPCOUNTS("m20kcod.db")

