Signal generation

Generate signal functions for system excitation.

dynax.aprbs(key, length, num_jumps, initial_value=None)

Generate an amplitude-modulated pseudo-random binary sequence (APRBS).

The output sequence contains numbers from [0, 1).

PARAMETER	DESCRIPTION
key	JAX PRNGKey. TYPE: PRNGKeyArray
length	Number of samples in the sequence. TYPE: int
num_jumps	Number of jumps in the sequence. TYPE: int
initial_value	The inital value of the sequence. If None, it is chosen randomly. TYPE: float | None DEFAULT: None

RAISES	DESCRIPTION
ValueError	If the number of jumps exceeds the number of possible jumping points (length-2).

RETURNS	DESCRIPTION
Array	Array with shape (length,) describing the APRBS.

dynax.smooth_noise(key, length, sigma, start_at_zero=False)

Generate smooth noise.

Produces a smoothly varying signal with unit variance by convonvling a Gaussian kernel with white noise.

PARAMETER	DESCRIPTION
key	JAX PRNGKey. TYPE: PRNGKeyArray
length	Number of samples in the sequence. TYPE: int
sigma	Standard deviation of the Gaussian kernel. Larger values produce smoother outputs. TYPE: float
start_at_zero	If true starts the sequence at zero. Otherwise it starts with a random normaly distributed value. Defaults to False. TYPE: bool DEFAULT: False

RETURNS	DESCRIPTION
Array	Array with shape (length,) describing the smooth noise.

dynax.bandlimited_noise(key, length, max_freq=20, dt=None, normalize=True)

Generate 1D band-limited random noise using Fourier synthesis.

Note

The signal is periodic due to the Fourier-based construction.

PARAMETER	DESCRIPTION
key	JAX PRNGKey. TYPE: PRNGKeyArray
length	Number of points TYPE: int
max_freq	Cutoff frequency (max Fourier mode kept) TYPE: float DEFAULT: 20
dt	Time increment between samples. If none provided, uses dt=1/length. Defaults to None. TYPE: float | None DEFAULT: None
normalize	If true, normalizes the signal to zero mean and unit variance. TYPE: bool DEFAULT: True

RETURNS	DESCRIPTION
Array	Smooth noise of length N