[gmx-users] Command line to obtain multiple eigenvectors

[Justin Lemkul]

On 2/28/13 4:40 AM, Ashalatha Sreshty wrote:
> Dear Users,
>
> My Problem is in regard to Principal Component Analysis. It might be
> trivial, but I am not been able to hit at the right place. So please help.
>
> I did PCA on a 100ns trajectory and also obtained the eigenvalues.xvg and
> eigenvec.trr, Now that I want to get the first four eigenvector
> projections, but could do so only one by one using the command line
>
> g_anaeig_d  -f MD-full.xtc -v eigenvec.trr -s reference.tpr -eig
> eigenval.xvg -n MD.ndx -proj proj.xvg -first 1 -last 1
>
> g_anaeig_d  -f MD-full.xtc -v eigenvec.trr -s reference.tpr -eig
> eigenval.xvg -n MD.ndx -proj proj.xvg -first 2 -last 2
>
> So, I want to know whether there is a command line to obtain the first four
> or even more eigenvectors in a single output file.
>

Using -first 1 -last 4 will write the first four eigenvectors.

-Justin

-- 
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Justin A. Lemkul, Ph.D.
Research Scientist
Department of Biochemistry
Virginia Tech
Blacksburg, VA
jalemkul[at]vt.edu | (540) 231-9080
http://www.bevanlab.biochem.vt.edu/Pages/Personal/justin

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