01.Introduction package:limma R Documentation _I_n_t_r_o_d_u_c_t_i_o_n _t_o _t_h_e _L_I_M_M_A _P_a_c_k_a_g_e _D_e_s_c_r_i_p_t_i_o_n: LIMMA is a library for the analysis of gene expression microarray data, especially the use of linear models for analysing designed experiments and the assessment of differential expression. LIMMA provides the ability to analyse comparisons between many RNA targets simultaneously in arbitrary complicated designed experiments. Empirical Bayesian methods are used to provide stable results even when the number of arrays is small. The normalization and data analysis functions are for two-colour spotted microarrays. The linear model and differential expression functions apply to all microarrays including Affymetrix and other multi-array oligonucleotide experiments. There are three types of documentation available. (1) The _LIMMA User's Guide_ can be reached through the "User Guides and Package Vignettes" links at the top of the LIMMA contents page. The function 'limmaUsersGuide' gives the file location of the User's Guide. (2) An overview of limma functions grouped by purpose is contained in the numbered chapters at the top of the LIMMA contents page, of which this page is the first. (3) The LIMMA contents page gives an alphabetical index of detailed help topics. The function 'changeLog' displays the record of changes to the package. _A_u_t_h_o_r(_s): Gordon Smyth _R_e_f_e_r_e_n_c_e_s: Smyth, G. K., Yang, Y.-H., Speed, T. P. (2003). Statistical issues in microarray data analysis. _Methods in Molecular Biology_ 224, 111-136. Smyth, G. K. (2005). Limma: linear models for microarray data. In: 'Bioinformatics and Computational Biology Solutions using R and Bioconductor'. R. Gentleman, V. Carey, S. Dudoit, R. Irizarry, W. Huber (eds), Springer, New York, 2005.