On 12-08-28 5:32 PM, Marc Schwartz wrote:
On Aug 28, 2012, at 4:05 PM, Duncan Murdoch <murdoch.dun...@gmail.com> wrote:
Is there a function to efficiently search for a subsequence within a vector?
For example, with
x <- 1:100
I'd like to search for the sequence c(49,50,51), and be told that it occurs
exactly once, starting at location 49. (The items in the vectors might be
numeric or character, and there might be repetitions within the search pattern
or within the vector I'm searching.)
Duncan Murdoch
There is a thread here:
http://tolstoy.newcastle.edu.au/R/e17/help/12/02/4201.html
that has various solutions and towards the end has a post with some timings.
Thanks, that's helpful. I wonder if we should have a function based on
the fast solution in that thread (or something even faster written all
in compiled code; I suspect Boyer-Moore could do well, but not coded in R).
Duncan Murdoch
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