Additional features from Matlab version

[simmonsja]

Hey Spicer, hope you've been well!
Thanks for posting this python conversion, I am keen to try it out!
Just wondering if you had had a chance to look at any of the other estimation methods or datatypes. If not I am happy to help in porting these across.

[SBFRF]

Hey @simmonsja just seeing this message now. No, we haven't implemented any of the other estimation methods. Happy to accept pull requests!