OmicsMarkeR (version 1.4.2)

sorensen: Dice-Sorensen's Index

Description

Calculates Dice-Sorensen's index between two vectors of features. In brief, the closer to 1 the more similar the vectors. The two vectors may have an arbitrary cardinality (i.e. don't need same length). Very similar to the Jaccard Index jaccard but Dice-Sorensen is the harmonic mean of the ratio.

Usage

sorensen(x, y)

Arguments

x

vector of feature names

y

vector of feature names

Value

Returns the Dice-Sorensen's Index for the two vectors. It takes values in [0,1], with 0 meaning no overlap between two sets and 1 meaning two sets are identical.

References

Sorensen T. (1948) A method of establishing roups of equal amplitude in plant sociology based on similarity of species and its application to analyses of the vegetation on Danish commons. Kongelige Danske Videnskabernes Selskab. 5(4): 1-34.

Dice, Lee R. (1945) Measures of the Amount of Ecologic Association Between Species. Ecology 26 (3): 297-302. doi:10.2307/1932409

He. Z. & Weichuan Y. (2010) Stable feature selection for biomarker discovery. Computational Biology and Chemistry 34 215-225.

See Also

kuncheva, sorensen, ochiai, pof, pairwise.stability, pairwise.model.stability

Examples

# Dice-Sorensen demo
v1 <- paste("Metabolite", seq(10), sep="_")
v2 <- sample(v1, 10)
sorensen(v1, v2)