Composite Phase Deviation (Fischer & Roenneberg, 2016)

Combines, for each day, the deviation of the phase marker from the individual's own mean phase (precision) and from a reference phase (accuracy) as CPD = mean(sqrt(precision^2 + accuracy^2)). When no external reference phase is supplied, accuracy is measured from the individual's own mean phase. CPD is distinct from the circular SD reported by onset_timing_variability.

Usage

composite.phase.deviation(onset_hours, reference_phase = NULL)

Arguments

onset_hours

Numeric vector of daily phase-marker onset times in decimal hours (e.g. daily L5 onsets).

reference_phase

Optional reference phase in decimal hours (e.g. a scheduled/expected time, or a group mean). With the default NULL the accuracy term is measured from the individual's own mean phase, so it collapses onto the precision term and CPD = sqrt(2) * mean(|precision|), a within-individual dispersion measure. The published misalignment CPD of Fischer and Roenneberg requires an external reference_phase.

Value

List with CPD, precision (mean absolute deviation from own mean phase, hours), accuracy (mean absolute deviation from the reference, hours), reference_phase, and n_days.

References

Fischer D, Vetter C, Roenneberg T (2016). “A novel method to visualise and quantify circadian misalignment.” Scientific Reports, 6, 38601. doi:10.1038/srep38601 .