Activity Onset and Offset (Relative-Difference Phase Markers)

Finds the daily activity onset and offset by a relative-difference contrast on the averaged 24-hour profile: the onset is where mean activity rises most sharply (the relative difference of the window after versus before is largest) and the offset is where it falls most sharply. These are non-cosinor, non-changepoint phase markers, a normalized-contrast edge detector on the daily profile rather than a published actigraphy algorithm.

Usage

activity.onset.offset(counts, timestamps, window_hours = 6)

Arguments

counts

Numeric activity vector.

timestamps

POSIXct timestamps, one per value.

window_hours

Half-window, in hours, compared before versus after each minute (default 6).

Value

An object of class actiRhythm_aont: onset_h and offset_h (clock hours) and the relative-difference profile. Never errors.

Examples

ts <- seq(as.POSIXct("2024-01-01", tz = "UTC"), by = 60, length.out = 4 * 1440)
h  <- as.numeric(format(ts, "%H"))
activity.onset.offset(ifelse(h >= 23 | h < 7, 5, 300), ts)
#> Activity Onset / Offset
#> 
#>   Activity onset:  07.00 h
#>   Activity offset: 23.00 h
#>