Preprocessing of Gas Chromatography-Mass Spectrometry (GC-MS) data Package for the detection of molecules in complex mixtures of compounds. It creates an initial_DATA matrix from several GC-MS analyses by collecting and assembling the information from chromatograms and mass spectra (\emph{MS.DataCreation}).It tests for the best unsupervised clustering method to group similar mass spectra into molecules (\emph{MS.test.clust}).It runs the optimal unsupervised clustering method on the initial_DATA matrix, identifies the optimal number of clusters, produces different files for facilitating the quality control and identification of putative molecules, and returns fingerprinting or profiling matrices (\emph{MS.clust}).It converts output files from \emph{MS.clust} for NIST mass spectral library search and ARISTO webtool search Software Depends: amap, clValid, cluster, fpc Suggests: xcms, tcltk <yann.guitton@gmail.com> Elodie Courtois, Yann Guitton, Florence Nicole GPL-2 2012-05-04 application/tgz http://CRAN.R-project.org/package=MSeasy