R (>= 2.14.1), base, methods, datasets, utils, grDevices,
graphics, stats
R (>= 2.14.2), base, methods, datasets, utils, grDevices,
graphics, stats
R (>= 2.15.0), base, methods, datasets, utils, grDevices,
graphics, stats
R (>= 3.0.0), base, methods, datasets, utils, grDevices,
graphics, stats