Generalized Least- and Most-Active Periods (MX / LX)

The least-active LX and most-active MX periods for arbitrary window lengths, generalizing L5 and M10 (Van Someren et al. 1999). For each window the function returns the mean activity over the window and its onset and midpoint clock times. A fixed L5/M10 pair does not give these phase markers.

Usage

activity.extrema(counts, timestamps, windows = c(5, 10))

Arguments

counts

Numeric activity vector (minute epochs recommended).

timestamps

POSIXct timestamps, one per value.

windows

Window lengths in hours (default c(5, 10) = L5, M10).

Value

An object of class actiRhythm_mxlx: a data frame with, for each window, the least- and most-active mean level, onset hour, and midpoint hour. Never errors.

References

Van Someren EJW, Swaab DF, Colenda CC, Cohen W, McCall WV, Rosenquist PB (1999). “Bright light therapy: improved sensitivity to its effects on rest-activity rhythms in Alzheimer patients by application of nonparametric methods.” Chronobiology International, 16(4), 505–518. doi:10.3109/07420529908998724 .

Examples

ts <- seq(as.POSIXct("2024-01-01", tz = "UTC"), by = 60, length.out = 4 * 1440)
h  <- as.numeric(format(ts, "%H"))
activity.extrema(ifelse(h >= 23 | h < 7, 5, 300), ts, windows = c(5, 8, 10))
#> Least / Most Active Periods (MX / LX)
#> 
#>   L5: 5 at 00.0h   M5: 300 at 07.0h
#>   L8: 5 at 23.0h   M8: 300 at 07.0h
#>   L10: 64 at 21.0h   M10: 300 at 07.0h
#>