- index
A vector of date indices to create groups for.
- period
A character specification used for time-based grouping. The
general format to use is "frequency period"
where frequency is a number
like 1 or 2, and period is an interval like weekly or yearly. There must be
a space between the two.
Note that you can pass the specification in a flexible way:
This shorthand is available for year, quarter, month, day, hour, minute,
second, millisecond and microsecond periodicities.
Additionally, you have the option of passing in a vector of dates to
use as custom and more flexible boundaries.
- start_date
Optional argument used to
specify the start date for the
first group. The default is to start at the closest period boundary
below the minimum date in the supplied index.
- ...
Not currently used.