Is a list an atomic object? (or is there an issue with the help page of ?tapply ?)
Hi,
tapply() will work on any object 'X' that has a length and supports
single-bracket subsetting. These objects are sometimes called
"vector-like" objects. Atomic vectors, lists, S4 objects with a "length"
and "[" method, etc... are examples of "vector-like" objects.
So instead of saying
X: an atomic object, typically a vector.
I think it would be more accurate if the man page was saying something
like
X: a vector-like object that supports subsetting with `[`, typically
an atomic vector.
H.
On 02/04/2017 04:17 AM, Tal Galili wrote:
In the help page of ?tapply it says that the first argument (X) is "an atomic object, typically a vector." However, tapply seems to be able to handle list objects. For example: ################### l <- as.list(1:10) is.atomic(l) # FALSE index <- c(rep(1,5),rep(2,5)) tapply(l,index,unlist)
tapply(l,index,unlist)
$`1` [1] 1 2 3 4 5 $`2` [1] 6 7 8 9 10 ################### Hence, does it mean a list an atomic object? (which I thought it wasn't) or is the help for tapply needs updating? (or some third option I'm missing?) Thanks. ----------------Contact Details:------------------------------------------------------- Contact me: Tal.Galili at gmail.com | Read me: www.talgalili.com (Hebrew) | www.biostatistics.co.il (Hebrew) | www.r-statistics.com (English) ---------------------------------------------------------------------------------------------- [[alternative HTML version deleted]]
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