VMD-L Mailing List

From: Axel Kohlmeyer (akohlmey_at_gmail.com)
Date: Tue Oct 13 2009 - 11:29:09 CDT

joe,

you have to be careful with precence between operators.
if you want to make sure that an expression is evaluated
in a specific order, use parenthesis.

On Tue, Oct 13, 2009 at 11:39 AM, Joseph Bylund <joseph.bylund_at_gmail.com> wrote:
> Based on my understanding of selection syntax these two expressions should
> select an identical subset of atoms, however that's not what I'm
> experiencing. Should there be a difference and if so how can one interpret
> these two expressions
> "carbon and within 5 of resid 500"
> and
> "within 5 of resid 500 and carbon"

the first would select all carbon and then take a "within 5 of resid 500"
selection in that.

the second case would take a within 5 of (resid 500 and carbon)
this way the within should select atoms of any kind, which is obviously
not the same.

is this what you are seeing?

cheers,
   axel.

> Thanks,
> -Joe
>
> 

-- 
Dr. Axel Kohlmeyer    akohlmey_at_gmail.com
Institute for Computational Molecular Science
College of Science and Technology
Temple University, Philadelphia PA, USA.