[gmx-developers] trajana.h trajana.c

[Paolo Franz]

Thanks for the answer. Am I correct in saying that if I want to activate
two options (say ANA_USE_TOPX  and ANA_NOUSER_PBC, which might not make any
sense!) for a trajectory, I need to call gmx_ana_traj_create with
flags=ANA_USE_TOPX | ANA_NOUSER_PBC?

Sorry if my questions are silly, I am more familiar with c++ than c and I
have used rarely bitwise operations.
Cheers
Paolo

On 11 April 2012 11:26, Tsjerk Wassenaar <tsjerkw at gmail.com> wrote:

> Hi Paolo,
>
> If you use masking and other bitwise operations, it is handy to know
> which bit is set; the second for ANA_USE_TOPX and the fifth for
> ANA_NOUSER_PBC. Of course it's equal to 2 and 16, but that notation
> makes it a bit less obvious what to do with bitwise operations.
>
> Cheers,
>
> Tsjerk
>
> On Wed, Apr 11, 2012 at 11:18 AM, Paolo Franz <paolo.franz at gmail.com>
> wrote:
> > Hello everybody,
> > For sometimes, I have been developing analysis tools for gromacs
> > trajectories using the gromacs library. I am puzzled about some
> definitions
> > in the file trajana.h, which I do not seem to understand completely. Why
> are
> > definitions such as
> >
> > #define ANA_USE_TOPX         (1<<1)
> >
> > #define ANA_NOUSER_PBC       (1<<4)
> >
> > used in the code? What is the purpose of this bitwise shift - why not set
> > ANA_USE_TOPX and ANA_NOUSER_PBC to 2 and 16 for instance??
> >
> > Thanks in advance
> >
> > Paolo
> >
> >
> >
> > --
> > gmx-developers mailing list
> > gmx-developers at gromacs.org
> > http://lists.gromacs.org/mailman/listinfo/gmx-developers
> > Please don't post (un)subscribe requests to the list. Use the
> > www interface or send it to gmx-developers-request at gromacs.org.
>
>
>
> --
> Tsjerk A. Wassenaar, Ph.D.
>
> post-doctoral researcher
> Molecular Dynamics Group
> * Groningen Institute for Biomolecular Research and Biotechnology
> * Zernike Institute for Advanced Materials
> University of Groningen
> The Netherlands
> --
> gmx-developers mailing list
> gmx-developers at gromacs.org
> http://lists.gromacs.org/mailman/listinfo/gmx-developers
> Please don't post (un)subscribe requests to the list. Use the
> www interface or send it to gmx-developers-request at gromacs.org.
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://maillist.sys.kth.se/pipermail/gromacs.org_gmx-developers/attachments/20120411/75edea5b/attachment.html>