These functions can be used to convert the times of "ts" series
with frequency of 12 or 4 or objects of "yearmon" and
"yearqtr" class, as defined in the "zoo" package, to
chron dates.
Usage
## S3 method for class 'yearmon'
as.chron(x, frac = 0, holidays = FALSE, ...)
## S3 method for class 'yearqtr'
as.chron(x, frac = 0, holidays = FALSE, ...)
## S3 method for class 'ts'
as.chron(x, frac = 0, holidays = FALSE, ...)
Arguments
x
an object of class "yearmon" or
"yearqtr" or "ts" objects,
or a numeric vector interpreted “in years” and fractions of
years.
frac
Number between zero and one inclusive representing
the fraction of the way through the month or quarter.
holidays
If TRUE or a vector of chron dates, indicated
holidays and weekends are excluded so the return value will be a
non-holiday weekday.
...
Other arguments passed to chron.
Details
The "yearmon" and "yearqtr" classes are defined in
package zoo. If holidays is TRUE or a vector of
dates then the is.holiday function is used to determine whether
days are holidays.
The method for ts objects converts the times corresponding to
time(x) to chron. The ts series must have a frequency that is
a divisor of 12.
Value
Returns a chron object.
See Also
is.holiday,
ts
Examples
## Monthly time series data.
as.chron(AirPassengers)
as.chron(time(AirPassengers))
## convert to first day of the month that is not a weekend or holiday
as.chron(AirPassengers, frac = 0, holidays = TRUE)
## convert to last day of the month
as.chron(AirPassengers, frac = 1)
## convert to last day of the month that is not a weekend or holiday
as.chron(AirPassengers, frac = 1, holidays = TRUE)
## convert to last weekday of the month
as.chron(AirPassengers, frac = 1, holidays = c())
## Quarterly time series data.
as.chron(presidents)
as.chron(time(presidents))