import numpy as np
import matplotlib.pyplot as plt
from librosa import stft
from scipy.signal import windows

x = np.cos(2*np.pi * (2048//2 - 4) * np.linspace(0, 1, 2048, 0))
window = windows.dpss(512, 512//2-1)
Sx = stft(x, window=window, n_fft=len(window), hop_length=1)
plt.imshow(np.abs(Sx)[::-1], cmap='turbo', aspect='auto')