You failed to supply a raw value to match, and if you do it works:
match(as.raw(2), a)
[1] 9
for the ninth value is *not* '2, indeed': it is as.raw(2).
I think you are confusing R objects with their printed representation.
(In this case values are coerced to strings, and a[9] is thus coerced
to "02", which is not matched by the integer 02 nor the byte "\002".)
On Tue, 27 Jul 2010, bruno Piguet wrote:
Dear all,
Sorry to bother you with a question that must be a FAQ, but I'm not
clever enough to have Google give me the answer.
I want to filter out some bytes that I read in a file, before applying
rawToChar (to prevent null character problems)
So, I tried things like match("<some_byte>", my_raw_tab), but this
didn't work.
Here is a minimal example :
a <- charToRaw(paste("garbage", "\002", "some text", "\003", "garbage"))
print (a[9])
i <- match (02, a)
j <- match ('\002', a)
print (c(i, j))
All I get as result of "match" calls are NA's, while print (a[9]) ensures
me that the ninth value of a is 2, indeed.
Of course, hand-made search gives me the result :
for (i in seq(length(a)))
{
if (a[i] == 2) {
print (i)
}
}
Any hints ?
Thanks in advance,
Bruno.
PS : R version 2.11.0 (2010-04-22)
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--
Brian D. Ripley, rip...@stats.ox.ac.uk
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
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