hgu95av2CHR package:hgu95av2.db R Documentation _M_a_p _M_a_n_u_f_a_c_t_u_r_e_r _I_D_s _t_o _C_h_r_o_m_o_s_o_m_e_s _D_e_s_c_r_i_p_t_i_o_n: hgu95av2CHR is an R object that provides mappings between a manufacturer identifier and the chromosome that contains the gene of interest. _D_e_t_a_i_l_s: Each manufacturer identifier maps to a vector of chromosomes. Due to inconsistencies that may exist at the time the object was built, the vector may contain more than one chromosome (e.g., the identifier may map to more than one chromosome). If the chromosomal location is unknown, the vector will contain an 'NA'. Mappings were based on data provided by: Entrez Gene ( ftp://ftp.ncbi.nlm.nih.gov/gene/DATA ) on 2008-Apr2 _E_x_a_m_p_l_e_s: x <- hgu95av2CHR # Get the probe identifiers that are mapped to a chromosome mapped_probes <- mappedkeys(x) # Convert to a list xx <- as.list(x[mapped_probes]) if(length(xx) > 0) { # Get the CHR for the first five probes xx[1:5] # Get the first one xx[[1]] }