Merge adjacent bursts in an IMU vector — merge

For a given IMU vector, identify temporally adjacent bursts and merge them into a single burst. Bursts that end at the same time as the start time of the next burst are considered adjacent. Bursts with different frequencies or axes will not be merged.

Usage

merge_imu(x, ids = NULL, drop = FALSE)

Arguments

x: An IMU vector (e.g. acc, mag, gyro).
ids: Vector indicating groups to which the elements in x belong. If provided, bursts in x will not be merged across different values of this vector, even if their timestamps and frequencies align.
drop: Logical indicating whether to drop entries that have been merged into other bursts. If drop = FALSE (default), the output will have the same length as the input x, with NA values at positions where bursts were merged into a preceding burst. This is useful for retaining index matching between the input and output vectors.

Value

A vector of the same class as x.

Examples

a <- acc(
  list(cbind(X = 1:60, Y = 1:60), cbind(X = 61:100, Y = 61:100), cbind(X = 101:140)),
  frequency = units::set_units(20, "Hz"),
  start = as.POSIXct(c(0, 3, 5), tz = "UTC")
)

merge_imu(a)
#> <acceleration[3]>
#> [1] (50.5 50.5) <NA>        (120.5)    
#> # frequency: 20 [Hz]