How to read always from the first line when using READ in a loop?

[sky01237]

Hi, folks,
Here is the code:
SUBROUTINE CALCFG(N,X,F,G,ITER)
DOUBLE PRECISION X(N),G(N),F,A,d(5000),u(5000)
open (unit=2, file ="output.txt")
Do i = 1 , ITER - 1
Read( 2 , * )
End Do
Read( 2 , * ) d(ITER)
...


Do i = 1 , n - 1
Read( 2 , * )
End Do // it always starts from the next line of last iteration
How to make it start reading always from the first line for every iteration since in one iteration, maybe this subfunciton will be called several times and I want same data read in one iteration. Any help will be really appreciated. Thanks a lot.

Rui.

 

[minger]

I think you need to clarify a little, I'm pretty lost. Perhaps you could use the REWIND statement?
http://publib.boulder.ibm.com/infoc...p?topic=/com.ibm.xlf101a.doc/xlflr/rewind.htm

 

[quicknote]

Dear Rui,

Thank you for sharing your code and question. It seems like you are trying to read data from a file in a loop, but the loop is not starting from the first line of the file every time. This could be due to the fact that the file pointer is not being reset to the first line before each iteration.

To solve this issue, you can use the "rewind" function to reset the file pointer to the beginning of the file before each iteration. This will ensure that the data is read from the first line every time the loop is executed. Your code could look something like this:

SUBROUTINE CALCFG(N,X,F,G,ITER)
DOUBLE PRECISION X(N),G(N),F,A,d(5000),u(5000)
open (unit=2, file ="output.txt")
Do i = 1 , ITER - 1
Read( 2 , * )
End Do
Read( 2 , * ) d(ITER)
...


Do i = 1 , n - 1
rewind(2) // reset file pointer to the beginning of the file
Read( 2 , * )
End Do // it will now start reading from the first line every time

I hope this helps. Good luck with your research!

Best,