CODEWITHSUNDEEP
fortranfortran90
Mireanuw
Mireanuw

Reputation: 35

How to declare the unknown number of line from file

I have to work with a file that can change number of line due to the previous operation(from python script), and that number of line will used to declare the other variable, like this.

integer NumberOfLine  !This is not work,Of course.
real(8) F(FixedDimension,NumberOfLine)
integer, parameter :: NewDimension = ANumber*NumberOfLine

How can I declare the NumberOfLine properly. Thanks. I can pass number of line from python, So basicly I know that number after python operation complete

Upvotes: 0

Views: 89

Answers (1)

chw21
chw21

Reputation: 8140

If you declare a parameter, its value must be fixed at compile time. So your integer, parameter :: newDimension = ANumber * NumberOfLine cannot work if the compiler doesn't know the value of NumberOfLine.

What you can do is use allocatable arrays:

program test_alloc

    implicit none
    integer, parameter :: dp = selected_real_kind(p=15)
    real(kind=dp), dimension(:,:), allocatable :: F
    integer :: i
    integer, parameter :: FixedDimension = 10

    print *, "Enter i"
    read(*, *) i

    allocate (a(FixedDimension, i))
    a = i
    print *, a

end program test_alloc

Upvotes: 2

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