Checks how often a number sequence changes from decreasing
monotonically to increasing monotonically (or vice versa).
Usage
direction_changes(numeric_vector)
Value
Single number indicating how often numeric_vector
changes direction (0 to +Inf).
Arguments
numeric_vector
Numbers, ordered by their time of appearance.
Details
The supplied vectors are assumed to be ordered by time.
Values do not have to be strictly monotonically in-/decreasing.
I.e., c(0, 1, 1, 2) would return 0,
as \(x_n >= x_n-1\) is satisfied for \(2 <= n <= length(c(0, 1, 1, 2))\).
References
Wirth, R., Foerster, A., Kunde, W., & Pfister, R. (2020).
Design choices: Empirical recommendations for designing two-dimensional
finger tracking experiments. Behavior Research Methods, 52, 2394 - 2416.
tools:::Rd_expr_doi("10.3758/s13428-020-01409-0")