glapply: Group Level Apply

In informR: Sequence Statistics for Relational Event Models

Description

Apply a function on a variable over levels of an grouping factor. A wrapper for split() and is similar in functionality to by() but with more options for output.

Usage

glapply(x, id, FUN, regroup = TRUE, ...)

Arguments

x	a string or numeric vector.
id	grouping factor with length(x)
FUN	Function to apply over x
regroup	logical, if TRUE returns result in the same structure as x, otherwise, returns a list of length unique(id).
...	Additional arguments passed to FUN

Author(s)

Christopher Steven Marcum

See Also

split,unsplit,lapply

Examples

data(Indometh)
glapply(Indometh$conc,Indometh$Subject,FUN=mean)
x<-rep(sample(1:10),2)
id<-rep(letters[1:5],4)
glapply(x,id,FUN=function(x)sum((x-mean(x))^2),regroup=FALSE)
glapply(x,id,FUN=function(x)sum((x-mean(x))^2),regroup=TRUE)
#Compare with output produced by by()
by(x,id,function(x)sum((x-mean(x))^2))

informR documentation built on May 1, 2019, 9:22 p.m.