`scipy.signal._short_time_fft:ShortTimeFFT.istft`

source: /scipy/signal/_short_time_fft.py :1452

Signature

   def     istft (    self    ,    S  :  np.ndarray    ,    k0  :  int    =  0   ,    k1  :  int | None    =  None   ,  * ,     f_axis  :  int    =  -2   ,    t_axis  :  int    =  -1     )   →  np.ndarray

Summary

Inverse short-time Fourier transform.

Extended Summary

It returns an array of dimension S.ndim - 1 which is real if onesided_fft is set, else complex. If the STFT is not invertible, or the parameters are out of bounds a ValueError is raised.

Parameters

S: A complex valued array where f_axis denotes the frequency values and the t-axis dimension the temporal values of the STFT values.
k0, k1: The start and the end index of the reconstructed signal. The default (k0 = 0, k1 = None) assumes that the maximum length signal should be reconstructed.
f_axis, t_axis: The axes in S denoting the frequency and the time dimension.

Notes

It is required that S has f_pts entries along the f_axis. For the t_axis it is assumed that the first entry corresponds to p_min * delta_t (being <= 0). The length of t_axis needs to be compatible with k1. I.e., S.shape[t_axis] >= self.p_max(k1) must hold, if k1 is not None. Else k1 is set to k_max with

q_max = S.shape[t_range] + self.p_min
k_max = (q_max - 1) * self.hop + self.m_num - self.m_num_mid

The tutorial_stft section of the user_guide discussed the slicing behavior by means of an example.

Aliases