clear all
N=20; % number of subdivisions

for n=1:N
    a(n)=1+n/N;
    A=[0 0 0 0 127 4 80; 0.6747*a(n) 0.737 0 0 0 0 0; 0 0.0486 0.6610 0 0 0 0; 0 0 0.0147 0.6907 0 0 0; 0 0 0 0.0518 0 0 0; 0 0 0 0 0.8091 0 0; 0 0 0 0 0 0.8091 0.8089]
    lambda(n)=eigs(A,1);
end

plot(a,lambda,a,ones(size(a)),'-')
xlabel('a')
ylabel('lambda')