MDOF_Analysis.m

function [EVec, Eval, NatFreq, mu, gamma] = MDOF_Analysis(M,K)
%This function computes the eigenvectors and eigenvalues for a MDOF
%system which is described by the mass matrix M and the stiffness matrix K.
%{
INPUTS:
    M = The nxn mass matrix
    K = The nxn stiffness matrix

OUTPUTS:
EVec    = A nxn matrix whose columns are the eigenvectors for the system.
Eval    = A nx1 column vector whose elements are the eigenvalues for 
          the system.
NatFreq = A nx1 column vector whose elements are the natural frequencies 
          of the system. 
mu      = A nx1 column vector whose elements are the normalized modal
          masses.
gamma   = A nx1 column vector whose elements are normalized the model 
          stiffnesses.
%}


%Calculate the Eigenvectors:
[EVec, D] = eig(K, M);

%Calculate the eigenvalues and natural frequencies
Eval    = diag(D);
NatFreq = sqrt(Eval); %Rad/s

%Calculate the geeralized mass and stiffness values:
n = size(EVec,1); %Determine the size of the system (number of DOF)

%Preallocate:
mu    = zeros(n,1);
gamma = zeros(n,1);

for i = 1:n
    mu(i)    = transpose(EVec(:,i))*M*EVec(:,i);
    gamma(i) = transpose(EVec(:,i))*K*EVec(:,i);
end

end %End of MDOF_Analysis