Hmisc (version 5.3-0)

cut2: Cut a Numeric Variable into Intervals

Description

cut2 is a function like cut but left endpoints are inclusive and labels are of the form [lower, upper), except that last interval is [lower,upper]. If cuts are given, will by default make sure that cuts include entire range of x. Also, if cuts are not given, will cut x into quantile groups (g given) or groups with a given minimum number of observations (m). Whereas cut creates a category object, cut2 creates a factor object. m is not guaranteed but is a target.

cutGn guarantees that the grouped variable will have a minimum of m observations in any group. This is done by an exhaustive algorithm that runs fast due to being coded in Fortran.

Usage

cut2(x, cuts, m=150, g, levels.mean=FALSE, digits, minmax=TRUE,
oneval=TRUE, onlycuts=FALSE, formatfun=format, ...)
cutGn(x, m, what=c('mean', 'factor', 'summary', 'cuts', 'function'), rcode=FALSE)

Value

a factor variable with levels of the form [a,b) or formatted means (character strings) unless onlycuts is TRUE in which case a numeric vector is returned

See Also

cut, quantile, combine.levels

Examples

set.seed(1)
x <- runif(1000, 0, 100)
z <- cut2(x, c(10,20,30))
table(z)
table(cut2(x, g=10))      # quantile groups
table(cut2(x, m=50))      # group x into intevals with at least 50 obs.

table(cutGn(x, m=50, what='factor'))
f <- cutGn(x, m=50, what='function')
f
f(c(-1, 2, 10), what='mean')
f(c(-1, 2, 10), what='factor')
if (FALSE) {
  x <- round(runif(200000), 3)
  system.time(a <- cutGn(x, m=20))              # 0.02s
  system.time(b <- cutGn(x, m=20, rcode=TRUE))  # 1.51s
  identical(a, b)
}