fortran90 reading real numbers from file odd results

Asked Mar 17 '16 at 16:27

Active Mar 17 '16 at 20:02

Viewed 39 times

real*8, dimension (40) :: M(40)

...    

open(unit=99,file="input.inp")
do i=1,40
    read(99,*) M(i)
enddo

write(*,*) M(1)
...

In the file "input.inp", I have float numbers, like:

0.85
0.90
...

But when I read and write them on terminal, it gives me the first element: 0.849999...

How can I fix it to give me exact 0.85?

Edit: I compile it on gfortran. lol

edited Mar 17 '16 at 20:02

asked Mar 17 '16 at 16:27

user3817833

3

The exact value of 0.85 is 0.84999999999999997779553950749686919152736663818359375 – harold Mar 17 '16 at 16:31
set the precision to 2 or more decimal digits – phuclv Mar 17 '16 at 16:58
@HighPerformanceMark Had somebody added the fortran tag my close vote would have closed it immediately. – Vladimir F Героям слава Mar 17 '16 at 20:07

0 Answers0