neurodsp.sim.sim_knee¶
- neurodsp.sim.sim_knee(n_seconds, fs, exponent1, exponent2, knee)[source]¶
Simulate a signal whose power spectrum has a 1/f structure with a knee.
- Parameters
- n_secondsfloat
Simulation time, in seconds.
- fsfloat
Sampling rate of simulated signal, in Hz.
- exponent1float
Power law exponent before the knee.
- exponent2float
Power law exponent after the knee.
- kneefloat
Knee parameter.
- Returns
- sig1d array
Time series with the desired power spectrum.
Notes
This simulated time series has a power spectrum that follows the Lorentzian equation:
P(f) = 1 / (f**(exponent1) * f**(exponent2 + exponent1) + knee)
This simulation creates this power spectrum shape using a sum of sinusoids.
The slope of the log power spectrum before the knee is exponent1
The slope after the knee is exponent2, but only when the sign of exponent1 and exponent2 are the same.
Examples
Simulate a time series with exponent1 of -1, exponent2 of -2, and knee of 100:
>> sim_knee(n_seconds=10, fs=1000, exponent1=-1, exponent2=-2, knee=100)
