Posted by Terry J. Hilsabeck on August 02, 1998 at 01:30:16:
In Reply to: eigenvalue problem posted by K.A.Hafez on May 01, 1998 at 02:44:02:
I use the lapack function dgeev for eigenvalues of
a real non-symmetric matrix and it works very well.
: My Dear:
: I encounter a very strange/severe problem concerning the determination of the eigenvalue and the associated eigenvectors. I know eigenvalue problem is a very elementary problem nowadays, but really, I coldn't solve it myself. Even, I wrote a program for this, it didn't give rasonable results
: My problem concerning the solution of the following eigenvalue problem:
: {[K]-c^2[M]}.X=0.0
: where:
: K : is smmetric band real stiffness matrix (154x154)
: M: is antisymmetric real mass matrix (154x154)
: c: is the natura frequency or the eigenvalues
: X: is the eigenvector
: I already tried some routines called RGG and RG from the netlib, but any of them didn't give correct results. In fact all of them gave very strange results.
: Even I tried some checks to check the algorithm which already incorporated inside the subroutine, but I couldn't decide its suitablitiy.
: I would appreciate it if you are kind enoug and try to introduce any kind of help as soon as you can.
: waiting in front of the screen.
: sincerely,
: K.A.Hafez