On Fri, 13 Jun 2008, Daniel Malter wrote:
Hi,
I am trying to parse a large amount of text using gregexpr(). Unfortunately,
I get an "input buffer overflow" message when I attempt that with too large
an amount of text. The error messages occurs before the parsing. The problem
is that I cannot assign the text to a variable (an object) if the text is
too large.
R does have limits on the command line length (1024 bytes up to R-devel,
4096 bytes there). What happens if you exceed that depends on the
interface you are using (and you have not told us). Beyond that, the
parser has a limit of MAXELTSIZE (8192 bytes) on strings.
I don't see any need for 'improvement' though: why are you entering very
long strings as part of the R program? They are data, and e.g.
readLines() and scan() have no limits on string length beyond those
imposed by R's internals (2^31-1 bytes).
This problem has been mentioned before, which I found using the RSiteSearch.
However, the post is from 2006, and I thought it might have improved by now.
Is there any way to increase the limit or to get around this problem?
x="Saint Lucia, Saint Kitts and Nevis, Saint Helena, Clipperton Island,
Tristan da Cunha"
I presume that is not an example? It looks like a character vector which
has been collapsed by paste(x, ", ") and would be better strsplit() into
its components than using gregexpr.
#What I want to achieve is to parse the text for the number of occurrences
of a certain character string within the text.
#This is done using:
n=100 #choose n large enough
length(which(is.na(gregexpr("Saint",x,ignore.case=TRUE)[[1]][1:n])==FALSE))
But again, if the text is large, I cannot assign it to x. I'd be grateful
for any suggestions.
Cheers,
Daniel
-------------------------
cuncta stricte discussurus
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