[PD] tanh approximation

[Andy Farnell]

Yep, they both converge on tanh afaics. 
Your one is more efficient though, I'll use that.
(attached)

But what I don't understand is why it needs scaling and doesn't
naturally work over -1 to +1 

cheers,

Andy

On Tue, 7 Oct 2008 14:46:56 +0200
Thomas Grill <gr at grrrr.org> wrote:

> Hi,
> 
> > An approximation to tanh(x) is a continued fraction
> > x/1+ (x^2)/3+ (4x^2)/5+ (16x^2)/9+ ...
> 
> are you sure this is correct?
> Another well-known formulation is x/(1+x^2/(3+x^2/(5+x^2/(7+.....
> which works for me and converges quickly.
> see http://nrich.maths.org/public/viewer.php?obj_id=1451
> 
> gr~~~
> 


-- 
Use the source
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