Programming Example Report 14

program report14
implicit none
real(8)::t,k
real,parameter::TOL=1.0D-6
real(8),dimension(5)::NPV,s
integer::i

s(1)=0.0;s(2)=10.0;s(3)=15.0;s(4)=20.0;s(5)=25.0

do i=1,5
NPV(i)=forming(s(i))
End do

k=0.0
do while(forming(k)>=0)
k=k+TOL
enddo

write(*,'(T5,A,$)') "Rates of interest(%)"
write(*,'(T10,A)') "Net present values($)"
write(*,'(A)') repeat("=",55)

do i=1,5
write(*,'(T12,f5.2,T37,I10)') s(i),nint(NPV(i))
end do
write(*,'(A)') repeat("=",55)
write(*,'(A,F10.4,A)') "The internal rate of return is ", k,"%"

open(1,file="NPV.txt")
write(1,'(T5,A,$)') "Rates of interest(%)"
write(1,'(T10,A)') "Net present values($)"
write(1,'(A)') repeat("=",55)
do i=1,5
write(1,'(T12,f5.2,T37,I10)') s(i),nint(NPV(i))
end do
write(1,'(A)') repeat("=",55)
write(1,'(A,F10.4,A)') "The internal rate of return is ", k,"%"
close(1)

contains
function forming(t)
real(8)::forming,t,x
integer::i
x=t/100
forming=-300000+150000/(1+x)+150000/(1+x)**2+160000/(1+x)**3
end function forming

end program report14

! Result

! Rates of interest(%) Net present values($)
! =======================================================
! 0.00 160000
! 10.00 80541
! 15.00 49059
! 20.00 21759
! 25.00 -2080
! ============================================================
! The internal rate of return is 24.5366%