Here is how the data files contained in this package were produced:

1) Download the following files from UCSC to a DOWNLOAD dir:

   ftp://hgdownload.cse.ucsc.edu/goldenPath/sacCer1/bigZips/
     chromFa.zip (3.7M)

2) Shell commands:

   cd DOWNLOAD
   for i in `ls *.zip` ; do unzip $i ; done
   for i in `ls *.gz` ; do gunzip $i ; done
   R CMD INSTALL BSgenome.Scerevisiae.UCSC.sacCer1

3) R commands:

   library(BSgenome.Scerevisiae.UCSC.sacCer1)
   file <- system.file("scripts", "comments.R", package="BSgenome.Scerevisiae.UCSC.sacCer1")
   source(file)
   buildDataFiles("DOWNLOAD", "DATA", Scerevisiae@source_files, "", ".fa", comments)

