Extract instantaneous amplitude (envelope)

Extracts the instantaneous amplitude (envelope) from the analytic signal.

Usage

instantaneousAmplitude(x, assay_name = "analytic", output_assay = "amplitude")

Arguments

x

A PhysioExperiment object with analytic signal.

assay_name

Name of the analytic signal assay.

output_assay

Name for the output assay.

Value

A PhysioExperiment object with an additional assay (default "amplitude") containing the real-valued instantaneous amplitude (envelope) of the signal.

References

Oppenheim, A.V. & Willsky, A.S. (1997). "Signals and Systems." 2nd ed. Prentice Hall.

See also

hilbertTransform() which must be called first, instantaneousPhase() for the companion phase extraction, waveletTransform() for alternative time-frequency decomposition.

Examples

pe <- PhysioExperiment(
  assays = list(raw = matrix(rnorm(500 * 4), nrow = 500)),
  samplingRate = 100
)

# First compute Hilbert transform, then extract amplitude
pe <- hilbertTransform(pe)
pe <- instantaneousAmplitude(pe)