Align EMG to motion-capture sampling grid

Align EMG to motion-capture sampling grid

Usage

alignEMGtoMoCap(
  emg,
  emg_sampling_rate,
  mocap_length,
  mocap_sampling_rate,
  method = "linear",
  emg_start_time = 0,
  mocap_start_time = 0,
  outside = c("extend", "NA", "error")
)

Arguments

emg

Numeric vector or matrix of EMG data (time x channels).

emg_sampling_rate

EMG sampling rate (Hz).

mocap_length

Target number of MoCap samples.

mocap_sampling_rate

Target MoCap sampling rate (Hz).

method

Interpolation method passed to stats::approx().

emg_start_time, mocap_start_time

Finite scalar start times in seconds on the same reference clock. Defaults assume both recordings start at zero. These are known offsets; no synchronization or clock drift is estimated.

outside

Handling of target times outside each channel's finite-data support: "extend" repeats endpoints (compatibility default), "NA" leaves unavailable times missing, and "error" rejects the alignment. Fewer than two finite observations produce missing output, or an error under "error". Internal gaps are still interpolated; this policy checks support boundaries, not internal gap duration. No anti-alias filter is added. Endpoint differences within floating-point roundoff are snapped to the endpoint (tolerance capped at one millionth of the shorter sample interval).

Value

Matrix of aligned EMG data with mocap_length rows.

References

Merletti R, Parker PA (2004). "Electromyography: Physiology, Engineering, and Non-Invasive Applications." IEEE Press/Wiley.

See also

integrateEMGMoCap() for full EMG-MoCap integration, resampleSignal() for general signal resampling.

Examples

emg <- matrix(rnorm(2000), ncol = 2)
emg_aligned <- alignEMGtoMoCap(emg, 1000, mocap_length = 200,
                               mocap_sampling_rate = 100)