bug in `DamerauLevenshtein` about stringdistances.jl HOT 9 CLOSED

Also, Partial no longer normalizes by default.

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Thanks. How did you end up on this? I am now restricting the last argument to be an Integer (26221a1). Does that solve your issue?

from stringdistances.jl.

So I ended up at this issue by trying to answer: "does short word w appear in long string str up to 2 in DL-distance?". Since Partial invokes normalize, I first used e.g. Partial(DL)(w, str, 2 / length(w)), but I ran into issues where that would not identify correct matches, and I assumed it was due to floating point issues:

julia> w = "abcdef"
"abcdef"

julia> str = "1234abcxyf1234"
"1234abcxyf1234"

julia> Partial(DL)(w, str, 2 / length(w))
1.0

Here, the answer I want is 1/3, so that when I multiply by length(w) I indeed get 2, the unnormalized DL-distance between w and substrings of str. So I fixed it via

julia> Partial(DL)(w, str, (2 / length(w)) + eps())
0.3333333333333333

I thought things were working fine until I ran into a test query that did not match, which I reduced to the issue here.

I think therefore restricting to integers will at least error instead of giving the wrong answer, but I'm not sure it solves the problem completely, since I don't quite know how to do get the right functionality. I think maybe I should just vendor a copy of Partial and modify it to not normalize to avoid floating point issues altogether.

from stringdistances.jl.

Maybe I am using max_dist incorrectly. Is this right?

julia> DL("abcdef", "abcxyf", 2)
3

julia> DL("abcdef", "abcxyf",3)
2

I was thinking they both should be 2.

from stringdistances.jl.

Right, it's a bug. Thanks for spotting it. I think I have solved it with 4df4bad.
Let me know if you encounter other issues.

from stringdistances.jl.

Thanks for the quick fixes! I'll try again tomorrow and see if I can spot any issues.

from stringdistances.jl.

I haven't been able to find any more issues, by the way. I'll post a new issue if I find any.

Mind registering the latest release?

from stringdistances.jl.

ok, done. Let me know if you encounter other bugs — this is very useful.

from stringdistances.jl.

Will do, thanks!

from stringdistances.jl.