dot-gh_distance: Computes the Mahalanobis (GH) distance from scaled PLS scores

In proximetricsR: Spectral Preprocessing and Chemometric Calibration of NIR Sensors

Computes the Mahalanobis (GH) distance from scaled PLS scores

Description

Computes the squared Mahalanobis distance of each row of x to the origin, using the covariance matrix estimated from reference, normalized by the number of components used. The origin represents the center of the calibration score space. For calibration statistics, x and reference are the same (calibration) scaled scores. For new/prediction samples, reference must be the calibration model's scaled scores, so that the covariance is estimated from the calibration set and merely applied to (possibly few) prediction samples, rather than re-estimated from them.

Usage

.gh_distance(x, reference, ncomp)

Arguments

x	a matrix of scores scaled by their calibration standard deviations, for which the distance is computed.
reference	a matrix of scores scaled by their calibration standard deviations, used to estimate the covariance matrix. Typically the calibration model's scaled scores.
ncomp	a vector of component counts to compute the distance for.

Value

A matrix with one row per sample and one column per entry in ncomp.

proximetricsR documentation built on Sept. 4, 2026, 5:08 p.m.