[BioC] ggbio: Data stored twice in 'GGbio' object

[Julian Gehring]

Hi,

The 'ggbio::ggplot' (ggbio_1.9.7, R_2013-08-05 r63513) function seems to 
store its data twice.

   library(ggbio)
   df = data.frame(x = 1:10, y = rnorm(10))
   p = ggbio::ggplot(data = df)
   str(p)
   identical(p at data, p at ggplot$data)  ## TRUE

shows that the data 'df' is stored in p at data as well as p at ggplot$data.

Especially for large data sets, this is inefficient.  Is there a good 
reason for this?

Best wishes
Julian