[Rd] Argument recycling in substring()
Hervé Pagès
hpages at fhcrc.org
Fri Jun 4 02:53:33 CEST 2010
Hi,
According to its man page substring() "expands (its) arguments
cyclically to the length of the longest _provided_ none are of
zero length".
So, as expected, I get an error here:
> substring("abcd", first=2L, last=integer(0))
Error in substring("abcd", first = 2L, last = integer(0)) :
invalid substring argument(s)
But I don't get one here:
> substring(character(0), first=1:2, last=3L)
character(0)
which is unexpected.
Otherwise, yes substring() will recycle its arguments to the
length of the longest:
> substring("abcd", first=1:3, last=4:3)
[1] "abcd" "bc" "cd"
Cheers,
H.
--
Hervé Pagès
Program in Computational Biology
Division of Public Health Sciences
Fred Hutchinson Cancer Research Center
1100 Fairview Ave. N, M2-B876
P.O. Box 19024
Seattle, WA 98109-1024
E-mail: hpages at fhcrc.org
Phone: (206) 667-5791
Fax: (206) 667-1319
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