ADAS Subroutine ee2
FUNCTION EE2(X)
C
C-----------------------------------------------------------------------
C
C ****************** FORTRAN77 FUNCTION: EE2 **************************
C
C PURPOSE: EVALUATES EXP(X)E2(X) WHERE E2 IS THE 2ND EXPONENTIAL
C INTEGRAL
C
C CALLING PROGRAMS: GENERAL
C
C INPUT: (R*8) X = INDEPENDENT VARIABLE
C
C OUTPUT: (R*8) EE2 = EXP(X)E2(X)
C
C ROUTINES:
C ROUTINE SOURCE BRIEF DESCRIPTION
C -------------------------------------------------------------
C EEI ADAS EVALUATES 1ST EXPONENTIAL INTEGRAL
C
C UNIX-IDL PORT:
C
C VERSION: 1.1 DATE: 11-07-95
C MODIFIED: TIM HAMMOND (TESSELLA SUPPORT SERVICES PLC)
C - PUT UNDER S.C.C.S. CONTROL
C
C VERSION: 1.2 DATE: 06-03-96
C MODIFIED: TIM HAMMOND
C - ADDED HEADERS
C
C VERSION: 1.3 DATE: 17-4-07
C MODIFIED: HUGH SUMMERS
C - COMPLETED COMMENT BLOCK DESCRIPTION
C
C-----------------------------------------------------------------------
C
IMPLICIT REAL*8(A-H,O-Z)
IF(X-30.0D0)1,1,2
1 EE2=1.0D0-X*EEI(X)
GO TO 3
2 X1=1.0D0/X
EE2=X1*(1.0D0-X1*(2.0D0-X1*(6.0D0-X1*(24.0D0-X1*(120.0D0-X1*
1(720.0D0-X1*5040.0D0))))))
3 RETURN
END
REAL*8 X