I am trying to compute and plot the DTFT of bartlett window in dB scale but strange peaks appear instead of the round ones. I first compute the DTFT transform of the window, I am also shifting the DTFT and freqs, I compute the abs of the DTFT and I normalize the values of the shifted DTFT but the strange shapes/peaks appear as seen in the image below. I know that the DTFT of bartlett window is smoother. Am I doing something wrong?
N = 100
lobeWidth = 1 / fo
# creating the barlett window
bartlett = windows.bartlett(N, sym = True)
plt.plot(bartlett)
plt.show()
bartlett_fft = np.fft.fft(bartlett)
bartlett_freq = freq(bartlett_fft.shape[-1])
db_psd = 10 * np.log10(np.abs(shift((bartlett_fft + 0.00000000000001) / abs(bartlett_fft).max())))
plt.plot(shift(bartlett_freq), db_psd)
plt.show()
