The expression for "y" in the example below tabulates how many words matched for each line (i.e., line 2 matched 1 word, line 3 matched 3 words, and line 4 matched 2 words).
> x <- readLines("clipboard", -1)
> x
[1] "Is there a way to use regular expressions to capture two or more words in a "
[2] "sentence? For example, I wish to to find all the lines that have the words \"thomas\", "
[3] "\"perl\", and \"program\", such as \"thomas uses a program called perl\", or \"perl is a "
[4] "program that thomas uses\", etc."
> sapply(c("perl","program","thomas"), function(re) grep(re, x))
$perl
[1] 3
$program [1] 3 4
$thomas [1] 2 3 4
> unlist(sapply(c("perl","program","thomas"), function(re) grep(re, x)), use.names=F)
[1] 3 3 4 2 3 4
> y <- table(unlist(sapply(c("perl","program","thomas"), function(re) grep(re, x)), use.names=F))
> y
2 3 4 1 3 2 > which(y>=2) 3 4 2 3 >
hope this helps,
Tony Plate
At Monday 05:59 PM 7/12/2004, Sangick Jeon wrote:
Hi,
Is there a way to use regular expressions to capture two or more words in a
sentence? For example, I wish to to find all the lines that have the words "thomas",
"perl", and "program", such as "thomas uses a program called perl", or "perl is a
program that thomas uses", etc.
I'm sure this is a very easy task, I would greatly appreciate any help. Thanks!
Sangick
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