kexpiC.f File Reference

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Functions/Subroutines
real *8 function	kexpic (x)
real *8 function	keimlgc (x)
real *8 function	keiexpc (x)
real *8 function	kexpicorec (x)

Function/Subroutine Documentation

keiexpc()

real*8 function keiexpc

(

real*8

x

)

Definition at line 57 of file kexpiC.f.

References d0.

!     ***********
!
!     (ei(x)-log(x))*exp(-x)
!
      implicit none
      real*8 x
      real*8 g, kexpicorec, s
      data g/0.577215664d0/

      s = kexpicorec(x)
      if(x .lt. 14.) then
         keiexpc = (s + g)*exp(-x)      
      else
         keiexpc = s-exp(-x)* log(x)
      endif

keimlgc()

real*8 function keimlgc

(

real*8

x

)

Definition at line 38 of file kexpiC.f.

References d0.

!     ***********
!
!        ei(x)-log(x)
!
      implicit none
      real*8 x
      real*8 g, kexpicorec, s
      data g/0.577215664d0/

      s = kexpicorec(x) 
      if(x .lt. 14.) then
         keimlgc = s + g
      else
         keimlgc = exp(x)*s - log(x)         
      endif

kexpic()

real*8 function kexpic

(

real*8

x

)

Definition at line 22 of file kexpiC.f.

References d0.

      implicit none
      real*8 x
!
      real*8 kexpicorec, s, g
      data g/0.577215664d0/

      s = kexpicorec(x)
      if(x .lt. 14.) then
         kexpic=s + g + log(x)
      else
         kexpic=s*exp(x)
      endif

kexpicorec()

real*8 function kexpicorec

(

real*8

x

)

Definition at line 75 of file kexpiC.f.

References d.

      implicit none
!
      real*8 x
      real*8 eps, s, tmp, fn, tmp2
!
      data eps/1.d-6/

      s=0.
      tmp=1.
      if(x .eq.  0. ) then
         kexpicorec = 0.
      elseif(x .lt.14.) then
         fn=1.
 5       continue
         tmp=tmp*x/fn
         tmp2=tmp/fn
         s=s+tmp2
         if(abs(tmp2/s) .gt. eps) then
            fn=fn+1.
            go to 5
         endif
         kexpicorec = s
      else
         fn=15.
 105     continue
         s=s+tmp
         fn=fn-1.
         if(fn.gt.0.) then
            tmp=tmp*x/fn
            go to 105
         endif
         s=s/tmp/x
         kexpicorec = s
      endif