Thread: Read a table just once

Hello!

I'm not really good at C and I struggle for quite a long time to do something. Hope someone can help.

I am writing a user subroutine in C for a finite element (FE) solver. I would like to open a file which contains data needed in this routine. But I would like to open it just once, because the routine is called for each time step and each integration point of the meshed part of the FE problem. I though about using some kind of flag but it can't work since it is initialized at each new call of the routine.

Does anyone have an idea on how to do that?

Many thanks in advance,

ManonB

Thank you for answering !

By "user subroutine" do you mean "function"?

Yes I guess we can call it a function, it is called UMAT. The main "Programm" which solves the mechanical equations call this function at each integration point to have access to other equations to describe material behavior (these are in UMAT).
And to define all these equations in the function UMAT, I need data from the file I want to open, but just once at the beginning of the analysis and not each time the function UMAT is called.

currently I'm doing it like that:
FILE* file;
file=fopen("fort.12","r");

but as I said, it opens then several times...

If you cannot do that, then you might need to read the data from file once and store it in say, a static local structure or even a global structure, depending on your requirements

I don't understand what you mean by that. Are you talking about like "static int name" or something like that ? Could you please point me to an example ?

many thanks,

ManonB