! 2.15a.f90
!
! $Id: 2.15a.f90 1.2 2016/11/03 11:25:31 s Exp $
!
! bc, Before-tax cash flow  : �ňø‚«‘OƒLƒƒƒbƒVƒ…�Eƒtƒ��[
! da,  Depletion            : Œ¸‰¿�ž‹p 
! ti,  Taxable income       : ‰Û�Å‘Î�ÛŽû‰v
! tax                       : �Å‹à
! ac, After-tax cash flow   : �ňø‚«ŒãƒLƒƒƒbƒVƒ…�Eƒtƒ��[
! tr, tax rate              : �Å—¦
! ir, infration rate        : ƒCƒ“ƒtƒŒ—¦
! ic, initial capital expenditure : �‰ŠúŽ‘–{”ï—p
! r,  discount rate         : ‹à—˜
! df, discount factor       : Š„ˆøŒW�”(2011-10-29‰ü)
! ny                        : ”N�”
! pvac, present value of ac : �ňø‚«ŒãƒLƒƒƒbƒVƒ…�Eƒtƒ��[‚ÌŒ»�݉¿’l
!

program ex2_15a

implicit none
character(100) :: fmt1, fmt2, fmt3
integer :: k, ny
integer, dimension(0:10) :: i
double precision :: ic, ir, r, sumpv, tr
double precision :: ac(0:10), bc(0:10), da(0:10), df(0:10), pv(0:10)
double precision :: tax(0:10), ti(0:10)

! input
tr = 0.34d0
ir = 0.04d0
r  = 0.12d0
ic = 10.0d6
ny = 5
i(0:ny)  = (/(k, k = 0, ny)/)
bc(0:ny) = (/-ic,  2990.0d3, 2990.0d3, 2990.0d3, 2990.0d3, 2990.0d3/)
da(0:ny) = (/0.0d0,   ic/ny,    ic/ny,    ic/ny,    ic/ny,    ic/ny/)

! calculation
do k = 0, ny
  if(bc(k) - da(k) > 0)  then 
    ti(k) = bc(k) - da(k)
  else
    ti(k) = 0
  end if
end do
tax(0:ny) = ti(0:ny) * tr
ac(0:ny)  = bc(0:ny) - tax(0:ny)
df(0:ny)  = 1.0d0 / (1d0 + r) ** i(0:ny)
pv(0:ny)  = ac(0:ny) * df(0:ny)
sumpv     = sum(pv(0:ny))  

! output
fmt1 = '(a3, a10, a9, a13, a7, a10, a9,   a17)'
fmt2 = '(i3, i10, i9, i13, i7, i10, f9.2, i17)'
fmt3 = '(a61,i17)'
print *,    '2.15a.f90'
print fmt1, '”N', '�ňø‘OCF', 'Œ¸‰¿�ž‹p', '‰Û�Å‘Î�ÛŽû‰v', '�Å‹à', &
              '�ňøŒãCF', 'Š„ˆøŒW�”', '�ňøŒãCFŒ»�݉¿’l'
print *,    ('-', k = 1, 77)
print fmt2, (i(k), nint(bc(k)), nint(da(k)), nint(ti(k)), nint(tax(k)), &
               nint(ac(k)), df(k), nint(pv(k)), k = 0, ny)
print *,    ('-', k = 1, 77)
print fmt3, 'Œ»�݉¿’l=', nint(sumpv)

stop
end program ex2_15a