Dear list members, I'm analyzing factorial design in MAANOVA pockage. I wonder is it possible to construct contrast matrix for interaction of factors. I have 2x2 factorial design 2 maize lines (dh and dl) 2 temperature treatments (c and k). I want to get following contrasts: dhc vs dhk dlc vs dlk dhc vs dlc dhk vs dlk So I've made contrast matrix (assuming, that ordring of combination of factors is: dhc, dhk, dlc, dlk - is it right?): cont_matx=matrix(c(1,-1,0,0,0,0,1,-1,1,0,-1,0,0,1,0,-1),nrow=4,byrow=T ) And I've got this matrix > cont_matx [,1] [,2] [,3] [,4] [1,] 1 -1 0 0 [2,] 0 0 1 -1 [3,] 1 0 -1 0 [4,] 0 1 0 -1 But it doesn't work in: >test=matest(eth_logrg,model.nomainsample,term="linia:temp",Contrast=c ont_matx, n.perm=61,shuffle.method="resid") Error: The number 1 test is not estimable, I suppose that problem is with contrast matrix. I've searched the web a lot of time and find nothing helpful. So any help will be very appreciated. Yours sincerely, Maciej Jo?czyk, MSc Department of Plant Molecular Ecophysiology Institute of Plant Experimental Biology Faculty of Biology, University of Warsaw 02-096 Warszawa, Miecznikowa 1 ___________________________________ NOCC, http://nocc.sourceforge.net -- This email was Anti Virus checked by Astaro Security Gateway. http://www.astaro.com