[R-pkgs] update: zoo 0.9-9

[Achim Zeileis]

Dear useRs,

a new version of the zoo package for totally ordered observations is
available from CRAN. It contains many new features, the most important
of which are: support of regular time series, an improved merge method
and functions for carrying out rolling analyses of time series. A more
detailed list of changes and new features is given below.

All features (both old and new) are also documented in the package
vignette.

Best wishes,
Z


Changes in Version 0.9-9

  o regular "zoo" series: objects of class "zooreg" (inheriting from
    "zoo") can be used to store strictly regular series (similar to "ts"
    objects) or series with an underlying regularity (as before but with
    observations omitted). They have a frequency attribute that can be
    used for conversion between "zoo" and "ts". The function
    is.regular() can be used for checking the regularity of a series.

  o improved merge() method: merge.zoo now accepts non-zoo arguments
    (other than first) if all non-zoo args have the same NROW value
    as the first argument (or are scalar). In that case the non-zoo
    args are given the index of the first series. Scalars are added
    for the full index of the merged series.

  o merge() zoo can now optionally return a "data.frame" that contains
    the numeric columns as "zoo" series and the "zoo" objects created
    from factors converted back to "factor".
    
  o [.zoo allows now indexing using observations from the index scale
    (and not only observation numbers).

  o rapply, rollmean, rollmax, rollmedian to perform rolling analyses

  o extended functionality to plot.zoo type argument

  o when plot.zoo used with one series list(...) can be omitted from 
    various plotting parameter arguments

  o print.zoo documentation fix for R 2.1.0

  o yearmon and yearqtr datetime classes

  o head.ts, tail.ts

  o c.zoo, range.zoo

  o coredata.default, coredata.ts