reorder.factor {stats}  R Documentation 
reorder
is a generic function. Its "factor"
method
reorders the levels of a factor depending on values of a second
variable, usually numeric.
reorder(x, ...) ## S3 method for class 'factor': reorder(x, X, FUN = mean, ..., order = is.ordered(x))
x 
a factor (possibly ordered) whose levels will be reordered. 
X 
a vector of the same length as x , whose subset
of values for each unique level of x determines the
eventual order of that level.

FUN 
a function whose first argument is a vector and
returns a scalar, to be applied to each subset of X
determined by the levels of x .

... 
optional: extra arguments supplied to FUN 
order 
logical, whether return value will be an ordered factor rather than a factor. 
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.
Deepayan Sarkar deepayan@stat.wisc.edu
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")