Thanks. You are right. I have realized that the atv function returns empty for negative arguments. I was not aware that this would affect how sapply processes its result.
> > Quoting bic...@math.usask.ca: > >> Here is are a few lines of my R session: >> >>> class(income) >> [1] "integer" >>> class(sapply(1000*income-999,atv,sktaxb,sktax)) >> [1] "numeric" >>> class(sapply(1000*income-1001,atv,sktaxb,sktax)) >> [1] "list" >> >> Although "income" is a numeric array, and sapply works as expected >> returning an array (the function "atv" returns a single numeric >> argument), >> if subtract a large enough number from the first argument, the sapply >> function now wants to return a list? Am I missing something? >> >> I am running version 3.3.2 on Mac OS 10.9.9 >> > > You have not shown what 'income', 'atv', and so on are; so there is an > infinity > of possible reasons why you get a list instead of a numeric vector. > > One possible reason: what if 'atv' sometimes returns no value at all? > > f <- function(x) x[x>0] > str(sapply(1:10, f)) > ## int [1:10] 1 2 3 4 5 6 7 8 9 10 > > str(sapply(-5:5, f)) > ## List of 11 > ## $ : int(0) > ## $ : int(0) > ## $ : int(0) > ## $ : int(0) > ## $ : int(0) > ## $ : int(0) > ## $ : int 1 > ## $ : int 2 > ## $ : int 3 > ## $ : int 4 > ## $ : int 5 > > -- > Enrico Schumann > Lucerne, Switzerland > http://enricoschumann.net > > ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
