hgu95av2CHRLOC 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_a_l _L_o_c_a_t_i_o_n _D_e_s_c_r_i_p_t_i_o_n: hgu95av2CHRLOC is an R object that maps manufacturer identifiers to the starting position of the gene. The position of a gene is measured as the number of base pairs. _D_e_t_a_i_l_s: Each manufacturer identifier maps to a named vector of chromosomal locations, where the name indicates the chromosome. Due to inconsistencies that may exist at the time the object was built, these vectors may contain more than one chromosome and/or location. If the chromosomal location is unknown, the vector will contain an 'NA'. Chromosomal locations on both the sense and antisense strands are measured as the number of base pairs from the p (5' end of the sense strand) to q (3' end of the sense strand) arms. Chromosomal locations on the antisense strand have a leading "-" sign (e. g. -1234567). Since some genes have multiple start sites, this field can map to multiple locations. Mappings were based on data provided by: UCSC Genome Bioinformatics (Homo sapiens) ( ftp://hgdownload.cse.ucsc.edu/goldenPath/currentGenomes/Homo_sapiens ) on 2006-Apr14 _E_x_a_m_p_l_e_s: x <- hgu95av2CHRLOC # Get the probe identifiers that are mapped to chromosome locations mapped_probes <- mappedkeys(x) # Convert to a list xx <- as.list(x[mapped_probes]) if(length(xx) > 0) { # Get the CHRLOC for the first five probes xx[1:5] # Get the first one xx[[1]] }