Fortran loop for discrete values

Question

Is there any way to run a loop for discrete values of a variable? What about in some latest version?

Something like

for i in 1  5 9 11  31 77

used in Unix shell script?

I agree, should be able to say DO I=(/ 1,3,5,7 /) but you can't. Maybe it can be done with in implicit do. I will investigate. — John Alexiou
– John Alexiou, Commented Apr 3, 2014 at 13:50
@ja72: your assertion that someone is trying to write a Pascal program in Fortran is strange, Pascal provides no more support for 'looping' over an arbitrary list of numbers than Fortran does. Furthermore, OP indicates that she has drawn inspiration from Unix shell scripting. — High Performance Mark
– High Performance Mark, Commented Apr 3, 2014 at 14:48
@HighPerformanceMark in pascal you can loop over an emum with non sequential values. They have to be constants though. — John Alexiou
– John Alexiou, Commented Apr 3, 2014 at 14:55

M. S. B. · Accepted Answer · 2014-04-03 15:51:53Z

7

integer, dimension (5) :: indx = [5, 9, 11, 31, 71]

do i=1, size(indx)
   j=indx(i)
   ....
end do

edited Apr 3, 2014 at 15:51

answered Apr 3, 2014 at 13:12

M. S. B.

29.5k2 gold badges52 silver badges75 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Ben Criger · Accepted Answer · 2014-04-03 19:30:18Z

1

You can also use an implied do loop to accomplish this, but you'll have to define the array of values as above:

integer, dimension (5) :: indx = [5, 9, 11, 31, 71]
integer, dimension (5) :: rslt 
integer, external      :: func
rslt = (/ func(indx(j)), j=1,5 /)

answered Apr 3, 2014 at 19:30

Ben Criger

1501 silver badge7 bronze badges

Comments

John Alexiou · Accepted Answer · 2014-04-03 14:00:34Z

0

I am not sure if this helps, but you can use arrays for indeces

program Console1

implicit none

! Variables
INTEGER :: X(4) = (/ 1, 3, 5, 7 /)
REAL :: Y(10) = 0.0

! Body of Console1
print *, X
!   1   3   5   7
Y(X) = 10.0/X
print *, Y
!   10.0    0.0    3.33   0.0    2.00   0.0    1.428    0.0 ...

end program Console1

answered Apr 3, 2014 at 14:00

John Alexiou

29.4k12 gold badges83 silver badges136 bronze badges

Collectives™ on Stack Overflow

Fortran loop for discrete values

3 Answers 3

Comments

Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related