[R] overlapping pattern match

[Jerome Asselin]

Here's a way.

string <- "aaacdf"
pattern <- "aa"
nstring <- nchar(string)
npattern <- nchar(pattern)
stringlist <- substring(string, 1:(nstring-npattern+1), npattern:nstring)
sum(stringlist==pattern)

Also, have a look at: pmatch, charmatch, grep, sub, gsub, regexpr, chartr. I 
couldn't find a simple function to do what you want.

Hope this helps.

Jerome

On March 27, 2003 05:34 pm, Yiping Fan wrote:
> Content-Length: 360
> Status: R
> X-Status: N
>
> Hi, all,
>      I have a string like  "aaacdf",  I want to find how many "aa" in the
> string. Obviously, It is 2 in this case.  it is easy to do in Perl, but how
> to do such  overlapping match in R or Splus.  Thanks!
>
> Y.Fan
>
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