In ?agrep (grep with fuzzy matching) it mentions that I can set the argument fixed=FALSE to let my pattern be interpreted as a regular expression.
However, I can't get it to work!
agrep('(asdf|fdsa)', 'asdf', fixed=F)
# integer(0)
The above should match as the regular expression "(asdf|fdsa)" exactly matches the test string "asdf" in this case.
To confirm:
grep('(asdf|fdsa)', 'asdf', fixed=F)
# 1 : it does match with grep
And even more confusingly, adist correctly gives the distance between the pattern and string as 0, meaning that agrep should definitely return 1 rather than integer(0) (there's no possibility that 0 is greater than the default max.dist = 0.1).
adist('(asdf|fdsa)', 'asdf', fixed=F)
# [,1]
# [1,] 0
Why is this not working? Is there something I don't understand? A workaround?
I'm happy to use adist, but am not entirely sure how to convert agrep's default max.distance=0.1 parameter to adist's corresponding parameter.
(yes, I'm stuck on an old computer that can't do better than R 2.15.2)
> sessionInfo()
R version 2.15.2 (2012-10-26)
Platform: i686-redhat-linux-gnu (32-bit)
locale:
[1] LC_CTYPE=en_AU.utf8 LC_NUMERIC=C
[3] LC_TIME=en_AU.utf8 LC_COLLATE=en_AU.utf8
[5] LC_MONETARY=en_AU.utf8 LC_MESSAGES=en_AU.utf8
[7] LC_PAPER=C LC_NAME=C
[9] LC_ADDRESS=C LC_TELEPHONE=C
[11] LC_MEASUREMENT=en_AU.utf8 LC_IDENTIFICATION=C
attached base packages:
[1] stats graphics grDevices utils datasets methods base