What is the easiest and accurate way in Matlab to find the eigenvalues and eigenvectors of a problem that do have some zero diagonal elements?
7 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
How to find the eigenvalues and eigenvectors of a problem that have some zero diagonal elements which dont have the usual form of the standard eigenvalue problem?
clc
clear
K=load('Ks.mat').K;
M=load('Ms.mat').M;
%Eig Method
[Qi,D] = eig(K,M);
omega=sort(real(sqrt(real(diag(D)))*(0.7588455916e-5/0.15176911835e-5)));
omega=
2.40257944339103
2.40257944339103
3.70603843883719
4.39253729249290
4.39253729249290
.
.
.
%LV Method
m=2000;
n=800;
M11=M(1:m,1:m);
M12=M(1:m,m+1:m+n);
M21=M(m+1:m+n,1:m);
M22=M(m+1:m+n,m+1:m+n);
K11=K(1:m,1:m);
K12=K(1:m,m+1:m+n);
K21=K(m+1:m+n,1:m);
K22=K(m+1:m+n,m+1:m+n);
Mt=inv(sqrtm(M11));
LV=1000000;
A11=Mt*K11*Mt;
A12 = LV*Mt*K12;
A21 = LV*K21*Mt;
A22 = K22;
AA =[A11, A12;A21, A22];
[Qi, B]=eig((AA));
C=sqrt(diag(B));
D=C*(0.7588455916e-5/0.15176911835e-5);
Omega=sort(real(D))
1.54228989861890
2.33587868130244
2.98460674608965
3.31683033853761
The results obtained from LV method are much close to the results of the problem which are as below:
1.5477
2.2752
2.9762
3.3202
Why eig is unable to give an accurate result??
How I can get these results through eig command or other way you recommend?
2 commentaires
Réponses (0)
Voir également
Catégories
En savoir plus sur Operating on Diagonal Matrices dans Help Center et File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!