A simple wrapper to quickly estimate the periodicity
of a given data. Returning an object of type periodicity.
This calculates the
median number of days between observations
as a difftime object, the numerical difference,
the units of measurement,
and the derived scale of the data as a string.
The time index currently must be of either Date
or POSIX class, or coercible to such.
The only list item of note is the scale.
This is an estimate of the periodicity of the data
in common terms - e.g. 7 day daily data is best
described as ‘weekly’, and would be returned as
such.
Possible scale values are:
‘minute’,‘hourly’,
‘daily’,‘weekly’,
‘monthly’,‘quarterly’,
and ‘yearly’.