drosgenome1MAPCOUNTS     package:drosgenome1.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 _d_r_o_s_g_e_n_o_m_e_1._d_b

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

     drosgenome1MAPCOUNTS provides the "map count" (i.e. the count of
     mapped keys) for each map in package drosgenome1.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:

       drosgenome1MAPCOUNTS
       mapnames <- names(drosgenome1MAPCOUNTS)
       drosgenome1MAPCOUNTS[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 drosgenome1.db
       checkMAPCOUNTS("drosgenome1.db")

