hgu133plus2MAPCOUNTS     package:hgu133plus2.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 _h_g_u_1_3_3_p_l_u_s_2._d_b

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

     hgu133plus2MAPCOUNTS provides the "map count" (i.e. the count of
     mapped keys) for each map in package hgu133plus2.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:

       hgu133plus2MAPCOUNTS
       mapnames <- names(hgu133plus2MAPCOUNTS)
       hgu133plus2MAPCOUNTS[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 hgu133plus2.db
       checkMAPCOUNTS("hgu133plus2.db")

