rgu34aMAPCOUNTS          package:rgu34a.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 _r_g_u_3_4_a._d_b

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

     rgu34aMAPCOUNTS provides the "map count" (i.e. the count of mapped
     keys) for each map in package rgu34a.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:

       rgu34aMAPCOUNTS
       mapnames <- names(rgu34aMAPCOUNTS)
       rgu34aMAPCOUNTS[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 rgu34a.db
       checkMAPCOUNTS("rgu34a.db")

