buysbal {pastecs} | R Documentation |
Buys-Ballot table
Description
Calculate a Buys-Ballot table from a time-series
Usage
buysbal(x, y=NULL, frequency=12, units="years", datemin=NULL,
dateformat="m/d/Y", count=FALSE)
Arguments
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
|
Details
A Buys-Ballot table summarizes data to highlight seasonal variations. Each line is one year and each column is a period of the year (12 months, 4 quarters, 52 weeks,...). A cell ij of this table contain the mean value for all observations made during the year i at the period j.
Value
A matrix containing either the Buys-Ballot table (count=FALSE
), or the number of observations used to build the table (count=TRUE
)
Author(s)
Frédéric Ibanez (ibanez@obs-vlfr.fr), Philippe Grosjean (phgrosjean@sciviews.org)
See Also
daystoyears
, tsd
Examples
data(releve)
buysbal(releve$Day, releve$Melosul, frequency=4, units="days",
datemin="21/03/1989", dateformat="d/m/Y")
buysbal(releve$Day, releve$Melosul, frequency=4, units="days",
datemin="21/03/1989", dateformat="d/m/Y", count=TRUE)
[Package
pastecs version 1.4.2
Index]