Ann, heres a function to extract a vector of dfs using the input objects X, and classlabel inputs for mt.teststat. welchdf <- function(X, classlabel) { varx1 <- apply(X[,as.logical(classlabel)], 1, var) varx2 <- apply(X[,!as.logical(classlabel)], 1, var) n <- table(classlabel) df <- (((varx1/n[1])+varx2/n[2])^2)/(((varx1/n[1])^2)/(n[1]-1)+((varx2/n[2]) ^2)/(n[2]-1)) df } It gives similar figures to t.test(x,y, var.equal=F)$parameter for any row in X. marcus >>> Ann Hess <hess@stat.colostate.edu> 1/10/2003 8:41:39 AM >>> I am using mt.teststat (multtest) to obtain the teststatistics for Welch t-tests. I was wondering if there is a way to get the Satterthwaite (Welch) df for the tests using multtest. Any help would be appreciated. _______________________________________________ Bioconductor mailing list Bioconductor@stat.math.ethz.ch https://www.stat.math.ethz.ch/mailman/listinfo/bioconductor ______________________________________________________ The contents of this e-mail are privileged and/or confidential to the named recipient and are not to be used by any other person and/or organisation. If you have received this e-mail in error, please notify the sender and delete all material pertaining to this e-mail.