Dear Sir, Thank you Sir for the clarification. Need to explore about this.
Thanking you With Regards M. Kavyashree On Wed, Jun 8, 2011 at 2:35 PM, Tsjerk Wassenaar <tsje...@gmail.com> wrote: > Hi Kavya, > > > Thanks sir. I will go through them. However I have referred - > > "A Tutorial on Principle component Analysis" by Lindsay I Smith. > > Which gave a good understanding about the concepts. Still I > > have some doubts regarding eigen values, as you have told > > I will think over them again. > > I know that one :) I'd advise others thinking of using PCA in MD to > also read it... It also pays off to read a few more, though, to get > slightly different viewing angles and to get used to different ways of > telling the same story. > > > But one statement I was not clear from your previous mail that - > > "An eigenvalue is an RMSF of the collective motion." > > I shouldn't have said RMSF, as it's not the root. The first eigenvalue > is the variance or mean square fluctuation of the projection of your > data onto the first eigenvector. > > > > > These eigenvalues are the solutions for an Nth order equation > > arising from N X N covar (sorry for using this term again) matrix > > (considering only x component). If we consider this covar matrix > > as a transformation matrix, eigen value would give the magnitude > > and direction by which the eigenvector is transformed linearly. > > Is it correct? > > No, the matrix of eigenvectors is a transformation (rotation) matrix. > The eigenvectors in a sense give the directions of motion, and the > eigenvalues the magnitudes. > > Cheers, > > Tsjerk > > -- > Tsjerk A. Wassenaar, Ph.D. > > post-doctoral researcher > Molecular Dynamics Group > * Groningen Institute for Biomolecular Research and Biotechnology > * Zernike Institute for Advanced Materials > University of Groningen > The Netherlands > -- > gmx-users mailing list gmx-users@gromacs.org > http://lists.gromacs.org/mailman/listinfo/gmx-users > Please search the archive at > http://www.gromacs.org/Support/Mailing_Lists/Search before posting! > Please don't post (un)subscribe requests to the list. Use the > www interface or send it to gmx-users-requ...@gromacs.org. > Can't post? Read http://www.gromacs.org/Support/Mailing_Lists >
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