[gmx-users] Need help with fix for multiple pull groups

[YOLANDA SMALL]

Hello All,

I am trying to constrain the distance between part of a protein and a ligand, in
other words, constraints between two groups.  I had a problem with the second
pull group not being recognized during the trajectory run and I found a posting
on the developer list that specifies the following fix in the pullio.c code:

/gromacs3.2.1/scr/mdlib/pullio.c

> @@ -298,7 +298,7 @@
>    if (!strcmp(grpbuf[0],""))
>      fatal_error(0,"Need to specify at least group_1.");
>    pull->ngrp = 1;
> -  while (i<MAX_PULL_GROUPS && strcmp(grpbuf[pull->ngrp],""))
> +  while (pull->ngrp<MAX_PULL_GROUPS && strcmp(grpbuf[pull->ngrp],""))
>      pull->ngrp++;
>
>    fprintf(stderr,"Using %d pull groups\n",pull->ngrp);

I would like some confirmation before I proceed.  After I edit the pullio.c with
the suggested fix, what do I do next?

Thanks,
Yolanda