Docs for matplotlib.pyplot.specgram() reference an unsupported mode setting

[bcongdon]

Bug report

Bug summary

The docs for matplotlib.pyplot.specgram's mode argument reference the 'complex' mode setting, which is not a valid option:

'complex' returns the complex-valued frequency spectrum. (from here)

However, if you try to set mode='complex', you receive a ValueError due to this line of code:

matplotlib/lib/matplotlib/axes/_axes.py

Lines 7653 to 7654 in 74640bb

	if mode == 'complex':
	raise ValueError('Cannot plot a complex specgram')

Code for reproduction

import matplotlib.pyplot as plt
import numpy as np
plt.specgram(np.ones(1000), Fs=100, mode='complex')

Expected outcome

The docs should not reference the complex mode type if it is not planned supported.

Matplotlib version
N/A

[jklymak]

Care to open a PR - someone simply forgot to remove that phrase...

[bcongdon]

For sure! 😄 Just wanted to make sure that my understanding was correct.