Module EI in SPECFUN

• SPECFUN Information

• Components
  • Fullsource from NETLIB
  • Source from NETLIB
  • Test from NETLIB

EI

 
Computes the exponential integrals Ei(x), E1(x), and exp(-x)*Ei(x) for real
arguments x. Uses rational functions that theoretically approximate the
exponential integrals to at least 18 significant decimal digits.
 
Classes  :  C5 . Exponential and logarithmic integrals
 
Type     : Fortran subroutine in SPECFUN package.
Access   : Public domain. Portable.
Precision: Single or double.
Note     : Both single and double precision versions can be extracted from the
           supplied source with simple editing changes.
 
Usage    : S = EI(X); S = EONE(X); S = EXPEI(X)
 
Details  : Fullsource Source Test
Sites    : (1) NETLIB
 

Implementation of EI from SPECFUN on NETLIB

 
NETLIB:    Public access repository, The University of Tennessee at
           Knoxville and Bell Laboratories
 
Precision: Single or double.
Note     : Both single and double precision versions can be extracted from the
           supplied source with simple editing changes.
 
You may access components from NETLIB outside GAMS as follows.
 
   Source       : echo "send only ei from specfun" | mail netlib@ornl.gov
   Fullsource   : echo "send ei from specfun" | mail netlib@ornl.gov
   Test         : echo "send eitest from specfun" | mail netlib@ornl.gov