Normalized String Similarity
Normalized string similarities return a normalized similarity between two strings.
The returned distance is always in the range \([0, 1]\).
0indicates that neither string have anything in common.1indicates that both strings are equivalent. Equivalent strings are not necessarily identical.If two strings are identical, then it should always return
1.
The normalized similarity of any normalized string measure can always be computed as is computed as \(1 - distance(X, Y)\).
As stated in "Computation of Normalized Edit Distance and Applications",
Given two strings \(x\) and \(y\) over a finite alphabet, the normalized edit distance between \(x\) and \(y\), \(d(x,y)\) is defined as the minimum of \(W(p)/L(p)\), here \(p\) is an editing path between \(x\) and \(y\), \(W(p)\) is the sum of the weights of the elementary edit operations of \(p\), and \(L(p)\) is the number of these operations (length of \(p\)). (Marzal & Vidal, 1993)
References
Marzal, A., & Vidal, E. (1993-09). Computation of normalized edit distance and applications. IEEE Transactions on Pattern Analysis and Machine Intelligence, 15(9), 926–932. https://doi.org/10.1109/34.232078[sci-hub]
Author
Thibault Debatty, solonovamax