| reorder.factor {stats} | R Documentation |
Reorder levels of a factor
Description
Reorders the levels of a factor depending on values of a second variable, usually numeric.
Usage
## S3 method for class 'factor'
reorder(x, X, FUN = mean, ...,
order = is.ordered(x))
Arguments
x |
a factor (possibly ordered) whose levels will be reordered. |
X |
a vector of the same length as |
FUN |
a function whose first argument is a vector and
returns a scalar, to be applied to each subset of |
... |
optional: extra arguments supplied to |
order |
logical, whether return value will be an ordered factor rather than a factor. |
Value
A factor or an ordered factor (depending on the value of
order), with the order of the levels determined by
FUN applied to X grouped by x. The
levels are ordered such that the values returned by FUN
are in increasing order.
Additionally, the values of FUN applied to the subsets of
X (in the original order of the levels of x) is returned
as the "scores" attribute.
Author(s)
Deepayan Sarkar deepayan@stat.wisc.edu
Examples
bymedian <- with(InsectSprays, reorder(spray, count, median))
boxplot(count ~ bymedian, data = InsectSprays,
xlab = "Type of spray", ylab = "Insect count",
main = "InsectSprays data", varwidth = TRUE,
col = "lightgray")