Multiscale Intradaily Variability (IVm)

Intradaily variability computed across a set of bin sizes and averaged, the counterpart to multiscale interdaily stability (circadian.is.multiscale). Fragmentation that is invisible at the hourly scale often shows at finer bins, so the averaged IVm varies less across recordings than the single hourly IV (Goncalves et al. 2014).

Usage

intradaily.variability.multiscale(counts, timestamps, bin_minutes = 1:60)

Arguments

counts

Numeric activity vector.

timestamps

POSIXct timestamps, one per value.

bin_minutes

Bin sizes in minutes (default 1 to 60, per Goncalves et al. 2014).

Value

An object of class actiRhythm_ivm: a per-bin IV table and the averaged IVm. Never errors; returns NA on insufficient data.

References

Goncalves BSB, Cavalcanti PRA, Tavares GR, Campos TF, Araujo JF (2014). “Nonparametric methods in actigraphy: an update.” Sleep Science, 7(3), 158–164. doi:10.1016/j.slsci.2014.09.013 .

See also

circadian.is.multiscale

Examples

ts <- seq(as.POSIXct("2024-01-01", tz = "UTC"), by = 60, length.out = 3 * 1440)
h  <- as.numeric(format(ts, "%H"))
intradaily.variability.multiscale(ifelse(h >= 23 | h < 7, 5, 300), ts)
#> Multiscale Intradaily Variability
#> 
#>   IVm (averaged): 0.137
#> 
#>  bin_minutes          IV
#>            1 0.006251447
#>            2 0.012505790
#>            3 0.018763030
#>            4 0.025023170
#>            5 0.031286211
#>            6 0.037552156
#>            7 0.030231324
#>            8 0.025363425
#>            9 0.031711636
#>           10 0.062645012
#>           11 0.048476586
#>           12 0.075208914
#>           13 0.059410690
#>           14 0.058635458
#>           15 0.094076655
#>           16 0.063931049
#>           17 0.070327503
#>           18 0.064370776
#>           19 0.078840244
#>           20 0.125581395
#>           21 0.093998547
#>           22 0.097726887
#>           23 0.100205157
#>           24 0.078357397
#>           25 0.109348619
#>           26 0.116119329
#>           27 0.114449213
#>           28 0.125546284
#>           29 0.122368742
#>           30 0.188811189
#>           31 0.131938583
#>           32 0.160936531
#>           33 0.149314613
#>           34 0.146035800
#>           35 0.149708487
#>           36 0.132684653
#>           37 0.155550423
#>           38 0.187181810
#>           39 0.150143505
#>           40 0.134579439
#>           41 0.165639191
#>           42 0.189378057
#>           43 0.191448217
#>           44 0.198615186
#>           45 0.168421053
#>           46 0.202910241
#>           47 0.213954877
#>           48 0.200907806
#>           49 0.217924586
#>           50 0.215230312
#>           51 0.210418259
#>           52 0.227165187
#>           53 0.255578212
#>           54 0.237481797
#>           55 0.252917248
#>           56 0.244180296
#>           57 0.235365600
#>           58 0.258376506
#>           59 0.262059810
#>           60 0.380281690
#>