Error with wavelet_coherence when using freq_method='scale'

[LF-Earth]

Hi, thank you for Pyleoclim. It is a really nice project. I have been learning Python, so I have learned a lot using it.
When using this tutorial (http://linked.earth/PyleoTutorials/notebooks/L2_wavelet_analysis.html),
I tried to change the freq_method to scale:
coh = co2ts.wavelet_coherence(dDts,method='wwz', freq_method='scale')

I received the following error:

rect = np.zeros(length)
ValueError: negative dimensions are not allowed

Could you help me with that? If I try 'log', there is no problem.

[SHEN-Cheng]

This topic is quite similar to the issue: #623 (comment)

[CommonClimate]

Yes, this has been addressed by #635