| lapplyBy(doBy) | R Documentation |
Formula based version of lapply
Description
This function is a wrapper for calling lapply on the list resulting from first calling splitBy.
Usage
lapplyBy(formula, data = parent.frame(), FUN)
Arguments
formula |
A formula describing how data should be split |
data |
A dataframe |
FUN |
A function to be applied to each element in the splitted list, see 'Examples' below. |
Value
A list.
Author(s)
Søren Højsgaard, [email protected]
See Also
orderBy,
summaryBy,
transformBy,
splitBy,
Examples
data(dietox) ## Calculate weekwise feed efficiency = weight gain / feed intake dietox <- orderBy(~Pig+Time, data=dietox) v<-lapplyBy(~Pig, data=dietox, function(d) c(NA, diff(d$Weight)/diff(d$Feed))) dietox$FE <- unlist(v) ## Technically this is the same as dietox <- orderBy(~Pig+Time, data=dietox) wdata <- splitBy(~Pig, data=dietox) v <- lapply(wdata, function(d) c(NA, diff(d$Weight)/diff(d$Feed))) dietox$FE <- unlist(v)
[Package doBy version 1.9 Index]