survival (version 2.9-6)

tcut: Factors for person-year calculations

Description

Attaches categories for person-year calculations to a variable without losing the underlying continuous representation

Usage

tcut(x, breaks, labels, scale=1)

Arguments

x

numeric/date variable

breaks

breaks between categories, which are right-continuous

labels

labels for categories

scale

Multiply x and breaks by this.

Value

• An object of class tcut

See Also

cut, pyears

Examples

temp1 <- mdy.date(6,6,36)
temp2 <- mdy.date(6,6,55)# Now compare the results from person-years
#
temp.age <- tcut(temp2-temp1, floor(c(-1, (18:31 * 365.24))),
	labels=c('0-18', paste(18:30, 19:31, sep='-')))
temp.yr  <- tcut(temp2, mdy.date(1,1,1954:1965), labels=1954:1964)
temp.time <- 3700   #total days of fu
py1 <- pyears(temp.time ~ temp.age + temp.yr, scale=1) #output in days
py1