OmicsMarkeR (version 1.4.2)

ochiai: Ochiai's Index

Description

Calculates Ochiai'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 Ochiai is a geometric means of the ratio.

Usage

ochiai(x, y)

Arguments

x

Character vector of feature names

y

Character vector of feature names

Value

Returns the Ochiai 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

Ochiai A. (1957) Zoogeographical studies on the soleoid fishes found in Japan and its neigbouring regions. Bulletin of the Japanese Society of Scientific Fisheries. 22: 526-530.

Zucknick M., Richardson S., & Stronach E.A. (2008) Comparing the characteristics of gene expression profiles derived by univariate and multivariate classification methods. Statistical Applications in Genetics and Molecular Biology. 7(1): Article 7. doi:10.2202/1544-6115.1307

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

# Ochiai demo
v1 <- paste("Metabolite", seq(10), sep="_")
v2 <- sample(v1, 10)
ochiai(v1, v2)