Builds a stage-to-stage transition probability matrix and derives fragmentation indices from a staged hypnogram. Works with both full AASM and coarse actigraphy-derived staging.
Arguments
- hypnogram
A tibble returned by
read_hypnogram().- normalise
If
TRUE(default), each row of the transition count matrix is divided by its row sum to give transition probabilities. IfFALSE, raw transition counts are returned.
Value
A list with two elements:
- matrix
A square tibble (stages × stages) of transition probabilities or counts. Row = from stage, column = to stage.
- fragmentation
A one-row tibble with:
- n_transitions
Total number of stage transitions.
- fragmentation_index
Proportion of epochs that are followed by a different stage.
- wake_transitions
Number of transitions to Wake (proxy for arousal burden).
Examples
if (FALSE) { # \dontrun{
hyp <- read_hypnogram("night_001.csv")
trans <- compute_transitions(hyp)
trans$matrix
trans$fragmentation
} # }