R: Cut a Numeric Variable into Intervals

cut2 {Hmisc}

R Documentation

Cut a Numeric Variable into Intervals

Description

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.

Usage

cut2(x, cuts, m, g, levels.mean, digits, minmax=TRUE, oneval=TRUE)

Arguments

`x`	numeric vector to classify into intervals
`cuts`	cut points
`m`	desired minimum number of observations in a group
`g`	number of quantile groups
`levels.mean`	set to `TRUE` to make the new categorical vector have levels attribute that is the group means of `x` instead of interval endpoint labels
`digits`	number of significant digits to use in constructing levels. Default is 3 (5 if `levels.mean=TRUE`)
`minmax`	if cuts is specified but `min(x)<min(cuts)` or `max(x)>max(cuts)`, augments cuts to include min and max `x`
`oneval`	if an interval contains only one unique value, the interval will be labeled with the formatted version of that value instead of the interval endpoints, unless `oneval=FALSE`

Value

a factor variable with levels of the form [a,b) or formatted means (character strings)

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.