Similarity Indices

Jaccard = C
N1 + N2 - C
Simple Matching = C + A
N1 + N2 - C + A
Dice = 2C
N1 + N2
First Kulczynski = 2C
N1 + N2 - 2C
Second Kulczynski = C(N1 + N2)
2(N1N2)
Otsuka = C
ÖN1N2
Simpson = C
N1
Braun-Blanquet = C
N2
Fager =
C
ÖN1N2
- 1
2ÖN2
    A = absent in both areas
    C = present in both areas
    N1 = total present in first area
    N2 = total present in second area