VMD-L Mailing List

From: M K (mahyar.karimi20_at_gmail.com)
Date: Mon Nov 10 2014 - 18:55:41 CST

Thank you for your responses.

charge "-0.699000" ===> worked

charge == -0.699000 ===> didn't work

Thanks :)

On Wed, Sep 24, 2014 at 12:38 AM, Maxim Belkin <mbelkin_at_ks.uiuc.edu> wrote:

> How about "charge == -whatever" (without quotations)? It involves a couple
> of extra symbols, but it works.
>
> Maxim
>
>
>
> On Sep 23, 2014, at 9:08 AM, Josh Vermaas <vermaas2_at_illinois.edu> wrote:
>
> The negative sign. If you use charge "-0.7982", it'll work. John can
> probably be more enlightening about the details of WHY this is the case (I
> ran into this problem with negative resids, and I couldn't figure out why
> this was a problem), but the negative sign screws up the atomselection
> parser somehow unless its put in quotations. Note that negative numbers are
> allowed as math operands, so if you wanted charge > -0.8 and charge <
> -0.79, there the negative signs are handled correctly.
>
> -Josh Vermaas
> On 09/22/2014 09:25 PM, M Karim wrote:
>
> Hi,
>
> I have different atom types in the structure, and found the easiest way to
> select them by their charges. In the selection menu, I can easily select
> atom types with positive charges. However, atoms with negative charges are
> not selected and I get this error:
>
> *Unable to parse this atom selection.*
>
>
> I, for example, use this command in the Selected Atoms area:
>
> *charge -0.798200*
>
> The command window also shows:
>
> *ERROR) syntax error*
>
>
> What is the problem with the syntax?
>
> Thank you.
>
>
>
>