Exactly what algorithm are you using in Matlab to get the 10 smallest eigenvalues and their corresponding eigenvectors?
Barry > On Aug 15, 2020, at 8:53 PM, Nidish <n...@rice.edu> wrote: > > The section on solving singular systems in the manual starts with assuming > that the singular eigenvectors are already known. > > I have a large system where finding the singular eigenvectors is not > trivially written down. How would you recommend I proceed with making initial > estimates? In MATLAB (with MUCH smaller matrices), I conduct an eigensolve > for the first 10 smallest eigenvalues and take the eigenvectors corresponding > to the zero eigenvalues from this. This approach doesn't work here since I'm > unable to use SLEPc for solving > > K.v = lam*M.v > > for cases where K is positive semi-definite (contains a few "rigid body > modes") and M is strictly positive definite. > > I'd appreciate any assistance you may provide with this. > > Thank you, > Nidish
