[gmx-users] the eigenvalue in the principle component analysis

[xiao]

Hi Gromacs users,
 
I did the principle component analysis (PCA) on a MD trajectory, and i got a lot of  eigenvalues which range from 25 to 0, but i do not know which one is important. It is said that the larger the eigenvalue, the imporant it is, but i have no idea when it is safe to ignore an eigenvalue, i mean, is there a value cutoff which can tell us the important eigenvalues and unimporant eigenvalues.
 
Best wishes
 
Fugui