[gmx-users] Command line to obtain multiple eigenvectors

[Ashalatha Sreshty]

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.

Thank you in advance,

AshaLatha Sreshty
Molecular Biophysics Unit,
Indian Institute of Science.
Bangalore