An S3 class with methods for totally ordered indexed
observations. It is particularly aimed at irregular
time series of numeric vectors/matrices and factors.
zoo's key design goals are independence of a particular
index/date/time class and consistency with with ts and
base R by providing methods to extend standard generics.
chron, fCalendar, its, tseries, lattice, strucchange, DAAG
stats, utils, graphics, grDevices, lattice