On Aug 21, 2009, at 2:50 PM, stephen sefick wrote:
x <- "1041281__2009_08_20_.lev"
I would like to split this string up and only extract the leading
numbers.
1041281
to use as a label for a data column in a bigger for loop function to
read in data.
regards,
At least four options:
> gsub("_.*", "", x)
[1] "1041281"
> gsub("^([0-9]*)_.*", "\\1", x)
[1] "1041281"
> sapply(strsplit(x, split = "_"), "[", 1)
[1] "1041281"
> substr(x, 1, 7)
[1] "1041281"
The fourth example presumes that the initial numeric sequence is
always 7 characters in length. The first three do not make that
presumption.
All will work where 'x' might contain multiple entries of a similar
configuration as 'x'.
See ?gsub, ?regex, ?strsplit and ?substr for more information.
HTH,
Marc Schwartz
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