KWCChangepoint (version 0.2.3)

epidemic_test: Test for an epidemic period in data

Description

Test for a temporary change in the covariance operator of functional data using the FKWC (functional Kruskal–Wallis covariance changepoint) procedures outlined by Ramsay and Chenouri (2025).

Usage

epidemic_test(data, ranks = NULL, depth = c("RPD", "FM", "LTR", "FMd", "RPDd"))

Value

A list consisting of:

• $changepoints : Indices of the estimated start and end points for the epidemic period.

• $pvalue : The p-value based on the null distribution.

• $method : A string "Epidemic test (KWCChangepoint)"

Arguments

data

Data in matrix or data.frame form, where each row is an observation and each column is a dimension.

ranks

Optional if data is already ranked.

depth

Depth function of choice.

References

Ramsay, K., & Chenouri, S. (2025). Robust changepoint detection in the variability of multivariate functional data. Journal of Nonparametric Statistics. https://doi.org/10.1080/10485252.2025.2503891

Examples

set.seed(11)
epi_test <- rbind(replicate(3,rnorm(200)),
                  replicate(3,rnorm(200,10)),
                  replicate(3,rnorm(200,0.2)))

epidemic_test(epi_test)