Okay thanks. I also wonder the bcv <- 0.2 is like this in the user guide.
Typical values for the common BCV (square-rootdispersion) for datasets arising from well-controlled experiments are 0.4 for human data,
0.1 for data on genetically identical model organisms or 0.01 for technical replicates.
So I am identifiyng bcv as 0.4 since i am dealing with human data.
Gordon Smyth