[BioC] LIMMA functions

[Pingzhao Hu]

Dear Helper,

I am interested in using R package LIMMA.
I want to use the function BWSS in this package, but
I am not sure the meanings of the arguments of this function

bwss <- function(x,group).

the docu. explains they are:

x:     a numeric vector giving the responses. 
group: a vector or factor giving the grouping variable. 

For example, I have a microaray dataset.
gene1, .., gene 10 are grouped to group 1
gene11,...,gene 20 are grouped to group 2
gene21,.., gene 31 are grouped to group 3.

The tumors are t1, t2, .., t10.

For this dataset, how can I decide these two arguments: x and group????


By the way, the meanings of sums of squares between the group means (bss)
and sums of squares within the groups (wss) are the same as those
in Calinski & Harabasz (1974) CH(K)=(B(k)/(k-1)) / (W(k)/(n-k))?????

Your kind help is highly appreciated!!!!

Best regards,

ping