Naming of the Exponential Integrals



If you are interested to add the code of the Exponential Integrals to Maxima, I
would chose the name you prefer. It is no problem to go back to the name
logintegral_li for the Logarithmic Integral.

Here my to-do list for the Exponential Integrals:

1. Numerical routine for real and complex parameter of E[n](z)
   for Float and Bigfloat numbers.
2. Expansion in terms of the erfc function for half integral values
3. Transformation to a Hypergeometric representation 
4. Switching beetwen different representations, e.g.
   Exponential Integrals -> Gamma Incomplete or Trignometric Integrals
5. Support for symbolically complex characteristics like
   imagpart(expintegral_ei(z)), realpart(), conjugate() and cabs().

Dieter Kaiser

-----Urspr?ngliche Nachricht-----
Von: robert.dodier at gmail.com [mailto:robert.dodier at gmail.com] 
Gesendet: Samstag, 26. Juli 2008 17:52
An: Dieter Kaiser
Cc: maxima at math.utexas.edu
Betreff: Re: [Maxima] Naming of the Exponential Integrals

On 7/24/08, Dieter Kaiser <drdieterkaiser at web.de> wrote:

>  expintegral_e (n z) - Exponential Integral En
>  expintegral_e1 (z)  - Exponential Integral E1
>  expintegral_ei (z)  - Exponential Integral Ei
>  logintegral_li (z)  - Logarithmic Integral Li
>  expintegral_si (z)  - Exponential Integral Si
>  expintegral_ci (z)  - Exponential Integral Ci
>  expintegral_shi (z) - Exponential Integral Shi
>  expintegral_chi (z) - Exponential Integral Chi

I like this naming scheme better.

>  These names should emphasize that all this functions are sumerized as
>  Exponential Integrals. But to be consistent we have to use for Li the name
>  expintegral_li and not logintegral_li. I have chosen expintegral_li in my
last
>  revision of the code.

I think I like logintegral_li better, but either way it is OK by me.

best

Robert Dodier