// Calculate the instantaneous frequency from phase of differential spectrum
// Compute the fft. Conjugate here is to match DPWE
t = fft.fft(dwin * sample)[:F.shape[0]].conj()
t = t - 1.j * ww * D[:, i]
z_t2 = np.abs(D[:, i])**2
After Change
sample = y[i * hop_length : i * hop_length + n_fft]
t1 = fft.fft(fft.fftshift(dwin * sample)).conj()
t2 = fft.fft(fft.fftshift(window * sample)).conj()
// Store the STFT. Conjugate here to match DWPE"s matlab code.
D[:, i] = t2[:D.shape[0]] * window_norm
