[PD] tanh approximation

[Andy Farnell]

Hi all,

An approximation to tanh(x) is a continued fraction 

x/1+ (x^2)/3+ (4x^2)/5+ (16x^2)/9+ ...

See attached.

I got it working, but by trial and error needed to scale the
domain by 1/pi and add some weird scale to the range.
I'm confused about where these numbers come from. Can anyone
explain this please?

cheers,

Andy

-- 
Use the source
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