[BioC] maQualityPlots

[NATALIA F TCHETCHERINA]

Hello,
I use maQualityPlots for looking quality of my arrays.
It gives me plots in "png" files.
Question: Can I get these plots in "pdf" files?
I looked maQualityPlots code and think that I need to change "plotdef"
Question: How I should change "plotdef" to get my plots in "pdf" or may be I
need to change other part of maQualityPlot code?

Thanks in advance.
Natalia.