Re: [Axiom-mail] Exponential Integral (UNCLASSIFIED)

If you know of any other fits to interesting functions I'd appreciate a 
pointer to the work.
Finding high quality, numerically stable, smooth piecewise fits is a 
challenge.

Tim Daly
Axiom Lead Developer

Segletes, Steven (Civ,ARL/WMRD) wrote:
>
> Classification: _* UNCLASSIFIED*_
> Caveats: NONE
>  
> I was tickled to find mention of my exponential integral (E1(x)) 
> fitting algorithm at 
> _http://www.axiom-developer.org/axiom-website/patches/20080119.01.tpd.patch_ 
> .  As noted there, the accuracy of my published fit is only 4 decimal 
> places.  Years ago, I  extended that original fit to greater precision 
> (with more parameters of course), if it is of use to anyone, though I 
> have not published the extensions.  I do not subscribe to your 
> maillist, but am happy to provide the fits, should you provide your 
> request to me at [email protected]. 
>
> Regards,
> Steven Segletes
> U.S. Army Research Laboratory
> Aberdeen Proving Ground, MD 21005-5066
>
>
>
>  
> Classification: _* UNCLASSIFIED*_
> Caveats: NONE
>
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