Maxima: Exponential Integrals

Hello Oleg,

thank you very much for your interest on the Exponential integrals. 

I try to collect every material which is new for me and have put your link to my
favorites. A quick look shows me that the algorithm you have cited does a
quadrature (solve the integral) to evaluate the Exponential Integral. That is
quite different from the series expansion I have used to numerically evaluate
the function.

Dieter Kaiser

-----Urspr?ngliche Nachricht-----
Von: o.v.motygin at gmail.com [mailto:o.v.motygin at gmail.com] 
Gesendet: Mittwoch, 22. Oktober 2008 22:18
An: drdieterkaiser at web.de
Betreff: Maxima: Exponential Integrals

Dear Dieter,

I know that you are working on exponential integrals for Maxima
(http://www.math.utexas.edu/pipermail/maxima/2008/012453.html).
Thank you very much for your work, I hope it goes smoothly.

Do you know about the following implementation of E_n ? (Probably
it can help you in your work.)

Donald E. Amos, Computation of Exponential Integrals of a Complex
Argument, ACM Transactions on Mathematical Software, vol.16, no.2,
p.169--177, 1990, http://doi.acm.org/10.1145/78928.78933

Donald E. Amos, Algorithm 683: A Portable FORTRAN Subroutine for
Exponential Integrals of a Complex Argument, ACM Transactions on
Mathematical Software, vol.16, no.2, p.178--182, 1990,
http://doi.acm.org/10.1145/78928.78934

The fortran code of the subroutine is available at
http://www.netlib.org/toms/683
http://www.netlib.no/netlib/toms/683
http://www.mirrorservice.org/sites/netlib.bell-labs.com/netlib/toms/683.gz
http://scicomp.ewha.ac.kr/netlib/toms/683

With best wishes,
Oleg

---
D.Sc. Oleg V. Motygin,
Institute of Problems in Mech Engineering
Russian Academy of Sciences
V.O., Bol'shoj pr. 61
199178 St.Petersburg
Russia
email: o.v.motygin at gmail.com, mov222 at yandex.ru
http://www.ipme.ru/ipme/labs/mv/mov/index.html