Learning Fortran (2024)

Edit: and just three paragraphs in, the author admits they didn't even bother using the oldest version of FORTRAN itself.

So, "oldest" means "rather early".

Waitaminit, is that why we have "sub" in Visual Basic ?

https://en.wikipedia.org/wiki/Plankalk%C3%BCl

Some Fortran II conventions like the arithmetic IF are now deprecated, but `--std=legacy` is all it takes to make it compile today.

0 - https://en.wikipedia.org/wiki/EBCDIC

It also helps that Fortran compatibility is a must for pretty much anything that expects to use BLAS.

I wouldn't call multi-dimensional arrays tensors though. That's a bit of a bastardization of the term that seemed to be introduced by ML guys.

It wasn't until I started using Fortran that I realized how similar it is to BASIC which must have been a poor-man's Fortran.

You can do that, and it might be cleaner and less lines of code that way.

But you don't necessarily need to pass the array dimensions as a parameter, as you can call `size` or `shape` to query it inside your function.

    program main
      implicit none
    
      real :: a(2, 2) = reshape([1., 2., 3., 4.], [2, 2])
    
      call print_array(a)
    
    contains
    
      subroutine print_array(a)
        real, intent(in) :: a(:, :)
        integer :: n, m, i, j
    
        n = size(a, 1) ; m = size(a, 2)
        write(*, '("array dimensions:", 2i3)') [n, m]
        do i = 1, n
          do j = 1, m
            write(*, '(f6.1, 1x)', advance='no') a(i, j)
          end do
          print *
        end do
      end subroutine
    
    end program

At the time everyone seems to default to using C instead. But Fortran is so much easier! It even has slicing notations for arrays and the code looked so much like Numpy as you say.

Fortran in Modern Scientific Computing: An Unexpected Comeback - https://medium.com/@stack1/fortran-in-modern-scientific-comp...

5 Reasons Why Fortran is Still Used - https://www.matecdev.com/posts/why-fortran-still-used.html

Is Fortran better than Python for teaching the basics of numerical linear algebra? - https://loiseaujc.github.io/posts/blog-title/fortran_vs_pyth...

The trickiest part of really learning Fortran today is that it is hard to define what the language is, apart from the practical definition imposed by what its seven or so surviving compilers accept and how they interpret it. There are near-universally portable features that are not part of the ISO standard; there are standard features that are not at all portable, or not available at all anywhere. So what one should know as “Fortran” is its reasonably portable intersection of features across multiple compilers, and there isn’t a good practical book that will teach you that.