Leonardo Boava
2008-Feb-26 12:35 UTC
[R] Help needed to analyse a factorial microarray experiments! Newbie Question
Dear R-users: I am using the package MAANOVA to analyze microarray data and have encountered problems when trying to get interactions. I am a newbie in both, R and maanova, and I do not have good knowledge in statistical methods. I have four effects: Effects Levels Var 2 Ind 2 Trat 2 Time 4 Sample 3 <-- biological replicate Spot 4 <-- technical replicate I had fitted a model to got all interactions with Samples in random effect (mixed). But, I got an error when I include the Var:ind:Trat and Var:ind:Time in the fitted model. May be I didn't had degree of freedom enough. Then I did an analyses without those interactions (Var:ind:Trat and Var:ind:Time ). Now, I would like to known if are possible to get the interactions with three factors and interactions with four factors. I am interested in known which genes are differentially expressed in Var 1, Ind 2, Trat 1 , Time 3, for example. Could you address me how do I could do that? If I include the technical replicate in the model, can I get those interactions? If you had analysed a experiment like this, could you share your script? Does anyone have experience using MAANOVA commands and is willing to help? Any comments are very welcome! Thank you very much. Leonardo