Hi Dale, Thank you for your reply! Yes, the real term of all eigenvalues are very close to 1, and as I said in the previous email they matches a 2-fold rotational matrix. But I am just curious, would you mind if you give me a little bit of hint on what the imaginary space represent?
Thank you so much, Chen On Mon, Sep 22, 2014 at 1:26 PM, Dale Tronrud <[email protected]> wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > > On 9/22/2014 10:10 AM, Chen Zhao wrote: > > Hi all, > > > > I have a follow-up question here. I calculated the eigenvalues and > > the eigenvectors and some of them have imaginary terms. The real > > terms of the eigenvalues match a 2-fold rotation, but I am just > > wondering what the imaginary terms represent. It's been quite a > > while since I studied linear algebra. > > > > The eigenvalues for a rotation matrix will have one that is real > and the other two complex. The eigenvector that corresponds to the > real value is the rotation axis. The other two are not useful for > your purpose. > > By the way, that real eigenvalue has better be equal to one! > > Dale Tronrud > > > Thank you so much, Chen > > > > On Mon, Sep 22, 2014 at 10:41 AM, Philip Kiser <[email protected] > > <mailto:[email protected]>> wrote: > > > > Cool. Glad to help. > > > > On Mon, Sep 22, 2014 at 10:34 AM, Chen Zhao <[email protected] > > <mailto:[email protected]>> wrote: > > > > Dear Philip, > > > > Please forgive me! Yes it is eigenvectors that I am looking for. I > > was deriving myself and came to the conclusion that R=A^(-1)R'A, > > but I just forgot it is eigenvectors, and I forgot what the > > eigenvector is originally for. Thank you so much! > > > > Sincerely, Chen > > > > On Mon, Sep 22, 2014 at 10:22 AM, Philip Kiser <[email protected] > > <mailto:[email protected]>> wrote: > > > > Hi Chen, > > > > Wouldn't the fold of the NCS be clear from the PDB file? You could > > use superpose to superimpose one monomer onto the next member of > > the NCS group, and then take the rotation matrix output from that > > program to calculate the eigenvectors for the transformation. The > > NCS axis is parallel to one of those eigenvectors. > > > > Philip > > > > Philip > > > > On Mon, Sep 22, 2014 at 10:13 AM, Chen Zhao <[email protected] > > <mailto:[email protected]>> wrote: > > > > Dear all, > > > > Is there a software that can print out the position and the fold of > > a NCS rotational axis from a PDB file? (just something like molrep > > self-rotation on a reflection file) I cannot use molrep because the > > RMSD between the two copies are too high, and I just want to cut a > > certain region for calculation. I don't know whether calculated Fc > > from the truncated PDB works in molrep self-RF, but I am thinking > > whether there is a more straightforward way. > > > > Thanks a lot in advance! > > > > Sincerely, Chen > > > > > > > > > > > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v2.0.22 (MingW32) > > iEYEARECAAYFAlQgW7QACgkQU5C0gGfAG13IzQCeNPJi+TDEe7v/vI5Pzwm+/Vfb > dDEAniquuYawYm3ogMUa8yylMz51xUDQ > =bFra > -----END PGP SIGNATURE----- >
