Source: GitHub
Signature¶
def sdynpy.signal_processing.sdynpy_generator.pseudorandom(fft_lines, f_nyq, signal_rms=1, min_freq=None, max_freq=None, filter_oversample=2, integration_oversample=1, averages=1, shape_function=<function <lambda> at 0x7f7f9d170180>)Creates a pseudorandom excitation given the specified signal parameters
This function creates a pseudorandom excitation from a sum of sine waves with randomized phases. The function can return shaped input if the optional shape_function argument is passed.
Parameters¶
fft_lines : int The number of fft lines between 0 Hz and f_nyq, inclusive.
f_nyq : float The maximum frequency. The final sampling frequency will be f_nyq x filter_oversample x integration_oversample.
signal_rms : float The RMS amplitude of the signal. Default is 1.
min_freq : float The minimum frequency of the signal. If not specified, the minimum frequency will be the first frequency line (no 0 Hz component)
max_freq : float The maximum frequency of the signal. If not specified, the maximum frequency will be the nyquist frequency f_nyq.
filter_oversample : float The oversample factor that is used by some data acquisition systems to provide bandwidth for antialiasing filters. For example, in the I-DEAS data acquisition software, the true sampling frequency is 2.56x the nyquist frequency, rather than the 2x required by the sampling theorem. If not specified, the default factor is 2x.
integration_oversample : int An oversampling factor that may be desired for integration of a signal. Default is 1
averages : int The number of averages, or frames of data to create. For a pseudorandom input, each frame will be a replica of the first.
shape_function : function A shaping that can be applied to the signal per frequency line. If specified, it should be a function that takes in one argument (the frequency in Hz) and returns a single argument (the amplitude of the sine wave at that frequency).
Returns¶
times : np.ndarray A 1D array containing the time of each sample
signal : np.ndarray A 1D array containing the specified signal samples.