Learning FORTRAN In the Modern Era

Question

I\'ve recently come to maintain a large amount of scientific calculation-intensive FORTRAN code. I\'m having difficulties getting a handle on all of the, say, nuances, of a

Answer 1

Could you explain what you have to do in maintaining the code? Do you really have to modify the code? If you can get away by modifying just the interface to that code instead of the code itself, that would be the best.

The inherent problem when dealing with a large scientific code (not just FORTRAN) is that the underlying mathematics and the implementation are both complex. Almost by default, the implementation has to include code optimization, in order to run within reasonable time frame. This is compounded by the fact that a lot of code in this field is created by scientists / engineers that are expert in their field, but not in software development. Let's just say that "easy to understand" is not the first priority to them (I was one of them, still learning to be a better software developer).

Due to the nature of the problem, I don't think a general question and answer is enough to be helpful. I suggest you post a series of specific questions with code snippet attached. Perhaps starting with the one that gives you the most headache?