mahalanobis function

Mahalanobis Distance

Computes the squared Mahalanobis distance of all rows in x. methods

## S4 method for signature 'CompositionMatrix'
mahalanobis(x, center, cov, ..., robust = TRUE, method = c("mve", "mcd"))

## S4 method for signature 'ILR'
mahalanobis(x, center, cov, ..., robust = TRUE, method = c("mve", "mcd"))

Arguments

• x: A CompositionMatrix or an ILR object.
• center: A numeric vector giving the mean vector of the distribution. If missing, will be estimated from x.
• cov: A numeric matrix giving the covariance of the distribution. If missing, will be estimated from x.
• ...: Extra parameters to be passed to MASS::cov.rob(). Only used if robust is TRUE.
• robust: A logical scalar: should robust location and scatter estimation be used?
• method: A character string specifying the method to be used. It must be one of "mve" (minimum volume ellipsoid) or "mcd" (minimum covariance determinant). Only used if robust is TRUE.

Returns

A numeric vector.

Examples

## Data from Aitchison 1986
data("hongite")

## Coerce to compositional data
coda <- as_composition(hongite)

## Mahalanobis distance
mahalanobis(coda)

See Also

stats::mahalanobis()

Other statistics: aggregate(), condense(), covariance(), dist, margin(), mean(), pip(), quantile(), scale(), variance(), variance_total(), variation()

Author(s)

N. Frerebeau