
Hello,
I have a data frame >str(dat)'data.frame':  20000 obs. of 30 variables
it contains two information-two types of cancers:stage A(A1 to A10) and stage B(B1 to B20)  ##totally 30 patients-20000 sets of gene expression
I'd like to find the lists for top 20 differentially expressed genes using t-test (by P-value).
Here is my code, unfortunately it doesn't work...I need the help,please. I just learned R for two weeks, and hope you can give the hint!
> A<-dat[,1:10] > B<-dat[,11:30]> bb<-function(t.test)+ { P.value.to.return <- t.test(A,B)$p.value+ return(P.value.to.return)+ }> aa<-t(apply(dat,1,bb))
Thanks!!
Best Regards,vie


_________________________________________________________________


	[[alternative HTML version deleted]]


