Non-Parametric Measures of Actigraphy Data R package nparACT version 0.9.1 Computes interdaily stability (IS), intradaily variability (IV) & the relative amplitude (RA) from actigraphy data as described in Blume et al. (2016) <doi: 10.1016/j.mex.2016.05.006> and van Someren et al. (1999) <doi: 10.3109/07420529908998724>. Additionally, it also computes L5 (i.e. the 5 hours with lowest average actigraphy amplitude) and M10 (the 10 hours with highest average amplitude) as well as the respective start times. The flex versions will also compute the L-value for a user-defined number of minutes. IS describes the strength of coupling of a rhythm to supposedly stable zeitgebers. It varies between 0 (Gaussian Noise) and 1 for perfect IS. IV describes the fragmentation of a rhythm, i.e. the frequency and extent of transitions between rest and activity. It is near 0 for a perfect sine wave, about 2 for Gaussian noise and may be even higher when a definite ultradian period of about 2 hrs is present. RA is the relative amplitude of a rhythm. Note that to obtain reliable results, actigraphy data should cover a reasonable number of days. Software Depends: R (>= 3.5) Imports: ggplot2, grid, stringr, zoo, tools Suggests: knitr, rmarkdown, roxygen2 Christine Blume <christine.blume@unibas.ch> Comprehensive R Archive Network (CRAN) Christine Blume [aut, cre] (ORCID: <https://orcid.org/0000-0003-2328-9612>) GPL-3 2025-12-16 application/tgz https://CRAN.R-project.org/package=nparACT doi:10.32614/CRAN.package.nparACT en-GB