BTYD (version 2.4)

dc.RemoveTimeBetween: Remove Time Between

Description

This function creates a new event log, with time in the middle removed. Used, for example, in sports with off-seasons.

Usage

dc.RemoveTimeBetween(elog, day1, day2, day3, day4)

Arguments

elog

event log, which is a data frame with columns for customer ID ("cust"), date ("date"), and optionally other columns such as "sales". Each row represents an event, such as a transaction. The "date" column must consist of date objects, not character strings.

day1

date of beginning of first period. Must be a date object.

day2

date of end of first period. Must be a date object.

day3

date of beginning of second period. Must be a date object.

day4

date of third period. Must be a date object.

Value

list

elog1

the event log with all elog$date entries between day1 and day2

elog2

the event with all elog$date entries between day3 and day4

elog3

elog1 combined with elog2, with all dates from elog2 reduced by the time removed between elog1 and elog2

Details

The four date parameters must be in ascending order.

Examples

elog <- dc.ReadLines(system.file("data/cdnowElog.csv", package="BTYD"),2,3,5)
elog[,"date"] <- as.Date(elog[,"date"], "%Y%m%d")

# Use the cdnow data to return a 6 month event log for January, February,
# March, October, November, December.
period.one.start <- as.Date("1997-01-01")
period.one.end <- as.Date("1997-03-31")
period.two.start <- as.Date("1997-10-01")
period.two.end <- as.Date("1997-12-31")
reduced.elog <- dc.RemoveTimeBetween(elog, period.one.start, period.one.end,
                                     period.two.start, period.two.end)

# Note that the new elog will go up to June 30 at a maximum, since we
# are only using 6 months of data starting on January 1
max(reduced.elog$elog3$date)  # "1997-06-30"