istft#
- ShortTimeFFT.istft(S, k0=0, k1=None, *, f_axis=-2, t_axis=-1)[source]#
Inverse short-time Fourier transform.
It returns an array of dimension
S.ndim - 1
which is real ifonesided_fft
is set, else complex. If the STFT is notinvertible
, or the parameters are out of bounds aValueError
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.
See also
invertible
Check if STFT is invertible.
stft
Perform Short-time Fourier transform.
scipy.signal.ShortTimeFFT
Class this method belongs to.
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 top_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 notNone
. Else k1 is set tok_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 Short-Time Fourier Transform section of the SciPy User Guide discussed the slicing behavior by means of an example.