[gmx-developers] interface for externally calculated forces

[Anton Feenstra]

On 04/05/11 17:09, Rene Staritzbichler wrote:
> Anton,
>
>
> Wouldn't that make the interplay of Gromacs and the external program a
> bit more tricky?
>
>
> For the interface to be as general as possible, the external program
> would need to read from a file, do its calculations and write to a file.
>
>
> A callback is usually something like passing a function as a pointer to
> another function.
> But I saw that only within one program so far.
> Can one use that for the coordination of two separate programs?

That of course depends on what interface(s) the other program allows. If 
you can call it as a library function, that would allow passing a 
pointer to a function. But I think making a callback to something like 
the python wrapper, and then handling any calling is a good design.

Using the callback, you could still implement it using file IO etc and 
starting the other program, making it equivalent to the script option 
your proposed. But the callback could be much more manageable, more 
flexible, and potentially more efficient.

We have this now implemented to the point where you can initiate an MD 
run from your python script by calling a (new) library 'libmdrun'.
The mdrunnner function (vanilla gromacs) is now split into md_init(), 
md_integrate() and md_finalize() (and yes we found memory leaks and 
fixed all of them). Adding a callback functionality would not be much of 
a problem.


-- 
Groetjes,

Anton
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|  _   _  ___,| K. Anton Feenstra                                     |
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