- x
Either a vector with time values (in this case, `y`

must be defined), or a regular time-series

- y
If `x`

is a vector with time values, `y`

must contain corresponding observations

- frequency
The frequency of observations per year to use in the Buys-Ballot table. By default `frequency=12`

which corresponds to monthly samples, and the resulting table has 12 column, one per month

- units
either `"years"`

(by default), and time is not rescaled, or `"days"`

, and the time is rescaled to "years" with the function `daystoyears()`

- datemin
A character string representing the first date, using a format corresponding to `dateformat`

. For instance, with `datemin="04/23/1998"`

and `dateformat="m/d/Y"`

, the first observation is assumed to be made the 23th April 1998. In R, it can also be a POSIXt date (see `?DataTimeClasses`

). In this case, `dateformat`

is not required and is ignored. By default, `datemin=NULL`

- dateformat
The format used for the date in `datemin`

. For instance, `"d/m/Y"`

or `"m/d/Y"`

(by default). The distinction between "Y" and "y" is not important in Splus, but it is vital in R to use "y" for two-digit years (ex: 89) and "Y" for four-digits years (ex: 1989), or the date will not be correctly converted! In R, you can also use a POSIXt format specification like "%d-%m%Y" for instance (see `?strptime`

for a complete description of POSIXt format specification. In both Splus and R, you can also use "mon" for abbreviated months like "mon d Y" for "Apr 20 1965", and "month" for fully-spelled months like "d month Y" for "24 September 2003"

- count
If `FALSE`

(by default), the Buys-Ballot table is calculated. If `TRUE`

, the function returns only the number of observations that are used in each cell of the Buys-Ballot table