[BioC] affycomp, Variance across replicates plot,

[Mohammad Esad-Djou]

Hello, 
I reads "A benchmark for Affymetrix GeneChip expression measures" of Cope, Irizarry, Jaffee, Wu and Speed.

I would like compare four versions of RMA as Figure 2 (RMA, not multi-array, not robust and MM as PM) 
[See> The plots and statistics -- Variance across replicates plot, page 4]

But I do not know, is to use which instructions. Can someone help me?

Thanks,
Mohammad