[BioC] boxplot/histograms on preprocessed SNP affy data with crlmm package

[Javier Pérez Florido]

Dear list,
I have an SNP 6.0 affymetrix data set and before genotype calling, an 
exploratory analysis (boxplot, histograms, MAplots) on raw data are run 
by means of the oligo package.

However, I would like to run such exploratory analysis once the data is 
normalized. crlmm function from crlmm package performs genotype calling 
and returns an SNPSet object (calls, confs, SNP quality score and SNR 
information). However, I don't know how to access to normalized data to 
run such exploratory analysis and compare such analysis with the one run 
with raw data.

Any suggestions?
All the best,
Javier