phase_diffusion#

syncopy.synthdata.phase_diffusion(freq, eps=0.1, samplerate=1000, nChannels=2, nSamples=1000, rand_ini=False, return_phase=False, seed=None, nTrials=100)[source]#

Linear (harmonic) phase evolution plus a Brownian noise term inducing phase diffusion around the deterministic phase velocity (angular frequency).

The linear phase increments are given by

\[\Delta \phi = 2\pi \frac{freq}{samplerate}\]

The Brownian increments are scaled with eps relative to these phase increments, meaning the relative phase diffusion is frequency independent.

Parameters:

  • freq (float) – Harmonic frequency in Hz

  • eps (float) – Scaled Brownian increments 1 means the single Wiener step has on average the size of the harmonic increments

  • samplerate (float) – Sampling rate in Hz

  • nChannels (int) – Number of channels

  • nSamples (int) – Number of samples in time

  • rand_ini (bool, optional) – If set to True initial phases are randomized

  • return_phase (bool, optional) – If set to true returns the phases in radians

  • seed (None or int) – Set to an int to get reproducible results, or None for random ones.

  • nTrials (int or None) – Number of trials for the returned AnalogData object. When set to None a single-trial ndarray is returned.

Returns:

phases – Synthetic nSamples x nChannels data array simulating noisy phase evolution/diffusion

Return type:

syncopy.AnalogData or numpy.ndarray

Examples

Weak phase diffusion around the 60Hz harmonic:

>>> signals = spy.synthdata.phase_diffusion(freq=60, eps=0.01)

Return the unwrapped phase directly:

>>> phases = spy.synthdata.phase_diffusion(freq=60, eps=0.01, return_phase=True)