skdh.features.SPARC#

class skdh.features.SPARC(padlevel=4, fc=10.0, amplitude_threshold=0.05)#

A quantitative measure of the smoothness of a signal. SPARC stands for the SPectral ARC length.

Parameters:
padlevelint

Indicates the level of zero-padding to perform on the signal. This essentially multiplies the length of the signal by 2^padlevel. Default is 4.

fc: float, optional

The max. cut off frequency for calculating the spectral arc length metric. Default is 10.0 Hz.

amplitude_thresholdfloat, optional

The amplitude threshold to used for determining the cut off frequency up to which the spectral arc length is to be estimated. Default is 0.05

Attributes:
amp_thresh
fc
padlevel

Methods

compute(signal, fs, *[, columns, windowed])

Compute the SPARC

References

[1]

S. Balasubramanian, A. Melendez-Calderon, A. Roby-Brami, and E. Burdet, “On the analysis of movement smoothness,” J NeuroEngineering Rehabil, vol. 12, no. 1, p. 112, Dec. 2015, doi: 10.1186/s12984-015-0090-9.

compute(signal, fs, *, columns=None, windowed=False)#

Compute the SPARC

Parameters:
signalarray-like

Array-like containing values to compute the SPARC for.

fsfloat, optional

Sampling frequency in Hz. If not provided, default is 1.0Hz

axisint, optional

Axis along which the signal entropy will be computed. Ignored if signal is a pandas.DataFrame. Default is last (-1).

Returns:
sparcnumpy.ndarray

Computed SPARC.