Le package varmixt était un package définissant un modèle de mélange sur les variances dans le cadre de la recherche de gènes différentiellement exprimés entre deux conditions. Il n'est plus maintenu. La méthode est implémentée dans le package anapuce (fonction est.varmixt) et les fonctions DiffAnalysis.unpaired et DiffAnalysis permettent d'effectuer une analyse différentielle entre deux conditions en utilisant varmixt.
Motivation: Identifying differentially regulated genes in experiments comparing two experimental conditions is often a key step in the microarray data analysis process. Many different approaches and methodological developments have been put forward, yet the question remains open.
Results: Varmixt is a powerful and efficient novel methodology for this task. It is based on a flexible and realistic variance modelling strategy. It compares favourably with other popular techniques (standard t-test, SAM and Cyber-T). The relevance of the approach is demonstrated with real-world and simulated datasets. The analysis strategy was successfully applied to both a ‘two-colour’ cDNA microarray and an Affymetrix Genechip. Strong control of false positive and false negative rates is proven in large simulation studies.
