>>>>> "Spencer" == Spencer Graves <[EMAIL PROTECTED]>
>>>>> on Mon, 17 Feb 2003 17:43:23 -0800 writes:
Spencer> Hello: I'm not on the "r-devel" list, but I just
Spencer> modified "match.arg" from R 1.6.2 for Windows to
Spencer> accept a vector for "arg".
Spencer> Is it appropriate that I send such things to
Spencer> this email address for consideration for inclusion
Spencer> in a future release?
yes (using "R-devel" for ...).
But why is this current proposal really useful?
Note that I can't see reason to match more than one argument to the
*same* list of choices. `choices' already is a vector typically...
Making a function more complicated makes it also more
error-prone, so I think we'd need a good motivation for it.
E.g., your proposal below quite badly fails when
length(arg) == 0, since you've used the ``well-known to be unsafe''
1:length(arg) idiom instead of the safe seq(length= length(arg)) one.
Regards,
Martin
Spencer> I just compared this with "match.arg" in
Spencer> S-Plus 6.1 for Windows. There, I got the
Spencer> following:
>> match.arg(c("a","b"), c("aa", "bb"))
Spencer> [1] "aa" "bb"
Spencer> However, match.arg(c("a", "b")) in a test
Spencer> function with "default" = c("aa", "bb") returned
Spencer> only "a"; the following returns c("aa", "bb").
Spencer> Thanks for all your hard work in developing this
Spencer> marvelous product.
Spencer> Sincerely, Spencer Graves
match.arg <-
function (arg, choices)
{
if (missing(choices)) {
formal.args <- formals(sys.function(sys.parent()))
choices <- eval(formal.args[[deparse(substitute(arg))]])
}
# cat("choices =", choices, "\n")
for(j in 1:length(arg)){
if (all(arg[j] == choices))
arg[j] <- choices[1]
else{
i <- pmatch(arg[j], choices)
if (is.na(i))
stop(paste("ARG should be one of", paste(choices, collapse =
", "),
sep = " "))
if (length(i) > 1)
stop("there is more than one match in match.arg")
arg[j] <- choices[i]
}
}
arg
}
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