Methods of string distances

Intermediate Regular Expressions in R

Angelo Zehr

Data Journalist

Damerau-Levenshtein

rick caplan typo

Regular Levenshtein distance:

stringdist(a, b, method = "lv")

Damerau-Levenshtein distance:

stringdist(a, b, method = "dl")

Optimal String Alignment distance:

stringdist(a, b, method = "osa")

honolulu qgrams

honolulu hanolulu qgrams

qgrams("Honolulu", "Hanolulu", q = 2)

Returns:

   Ho on ul no ol lu la
V1  1  1  1  1  1  2  0
V2  1  1  1  1  1  1  1

Sum of qgrams that are not shared

stringdist(a, b, method = "qgram") # equals 4

Not shared qgrams divided by total number of qgrams

stringdist(a, b, method = "jaccard") # equals 0.5

Optimal String Alignment distance

stringdist(a, b, method = "cosine") # equals 0.22

Intermediate Regular Expressions in R