centring: QTS Centering and Standardization

In astamm/squad: Statistics for Quaternion Temporal Data

QTS Centering and Standardization

Description

This function operates a centering of the QTS around the geometric mean of its quaternions. This is effectively achieved by left-multiplying each quaternion by the inverse of their geometric mean.

Usage

centring(x, standardize = FALSE, keep_summary_stats = FALSE)

Arguments

x	An object of class qts.
standardize	A boolean specifying whether to standardize the QTS in addition to centering it. Defaults to FALSE.
keep_summary_stats	A boolean specifying whether the mean and standard deviation used for standardizing the data should be stored in the output object. Defaults to FALSE in which case only the centered qts is returned.

Value

If keep_summary_stats = FALSE, an object of class qts in which quaternions have been centered (and possibly standardized) around their geometric mean. If keep_summary_stats = TRUE, a list with three components:

• qts: an object of class qts in which quaternions have been centered (and possibly standardized) around their geometric mean;

• mean: a numeric vector with the quaternion Fréchet mean;

• sd: a numeric value with the quaternion Fréchet standard deviation.

Examples

centring(vespa64$igp[[1]])

astamm/squad documentation built on Jan. 26, 2024, 5:30 p.m.