[gmx-users] Fwd: Help on the vector component

[Tsjerk Wassenaar]

Hi Ankita,

If x, y, z are the components (or loadings), then "total" is sqrt(x**2 +
y**2 + z**2). They indeed define a direction, corresponding with the
direction of motion/spread associated with the eigenvector.

To compare eigenvectors, make sure that all frames in all trajectories are
oriented in the same way, using the same or a similar reference structure
for fitting. Then you can make a comparison like that.

Cheers,

Tsjerk


On Mon, Nov 25, 2013 at 1:00 AM, Ankita Naithani
<ankitanaithani at gmail.com>wrote:

> Hi Tsjerk,
>
> Thank you for your reply. So, basically the numbers are just the xyz
> components. and the Total is, I quite didn't understand what the total
> would be? If they are dimensionless, does that mean they are defining a
> direction? I mean should we say that the total component for instance is a
> measure of the direction of the eigenvector? Also, I was wondering if this
> could be valid to use for comparison between eigenvectors of different
> trajectories to account for or observe the similarity/dissimilarity amongst
> the two?
>
>
> Kind regards,
>
> Ankita
>
>
> On Sun, Nov 24, 2013 at 8:27 PM, Tsjerk Wassenaar <tsjerkw at gmail.com>
> wrote:
>
> > Hi Ankita,
> >
> > I had to check the source for this, but -comp writes out the eigenvector
> as
> > atom-coordinate components (x,y,z), and the norm of the eigenvector part
> of
> > the given atom (total). The numbers are dimensionless.
> >
> > Hope it helps,
> >
> > Tsjerk
> >
> >
> > On Sun, Nov 24, 2013 at 2:38 PM, Ankita Naithani
> > <ankitanaithani at gmail.com>wrote:
> >
> > > Hi,
> > >
> > > I wanted some help regarding vector components. I.e. when we use the
> > > g_anaeig command with a flag of -comp, it outputs a file of the
> > > corresponding eigenvector per atom. So, the x-axis has the atom number
> > and
> > > the Y-axis has the total, x, y and z components. I am not sure about
> what
> > > do they mean? Also, what are the units of these components? Like the
> > > numbers on Y-axis, what are the corresponding units? I would be really
> > > grateful if anyone could kindly help me on this.
> > > Apologies for reposting but was wondering if anyone has any thoughts on
> > it?
> > >
> > > Best wishes,
> > >
> > > --
> > > Ankita Naithani
> > >
> > >
> > >
> > > --
> > > Ankita Naithani
> > > --
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> >
> > --
> > Tsjerk A. Wassenaar, Ph.D.
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>
> --
> Ankita Naithani
> --
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-- 
Tsjerk A. Wassenaar, Ph.D.