define matrix with variable to iterate over

Hello, Its my first day at Matlab and I want to do the following:

I have a 9x9 matrix M(w) that has a variable w. I want to plot the 9 eigenvalues of M(w) (lets call them a_i with i=1,2,...,9) with respect to w. So in the end the graph is showing nine functions a_i(w) i=1,2,...,9.

My Code so far is:

w=(0:0.01:4)*ev/hb;
D_=zeros(9,length(w));
for n=1:length(w)
    M=(Here define matrix);
    [v,D]=eig(M);
    D_(:,n)=diag(D);
end

Plot(hb*w/ev,D_)

Put I dont know how to define M properly such that with each iteration comes a new value for w. I hope someone can help me

Answer 1

[Torsten]

function main
  ev = ...;
  hb = ...;
  w = (0:0.01:4)*ev/hb;
  D_= zeros(9,numel(w));
  for n = 1:numel(w)
    M = Define_Matrix_M(w(n));
    [~,D] = eig(M);
    D_(:,n) = diag(D);
  end
  plot(hb*w/ev,D_)
end

function M = Define_Matrix_M(w)
  % Set M depending on w here
end

[Alland Kiepert]

Thanks for the quick reply. I now get the following error:

File: test.m Line: 49 Column: 13

Invalid expression. When calling a function or indexing a variable, use parentheses.

Otherwise, check for mismatched delimiters.

In Line 49 I wrote:

function M =[....

is the syntax here wrong ?

[Torsten]

A line similar to

function M =[....

does not appear in my code suggestion.

[Alland Kiepert]

Oh. Youre right. I interpreted too much in your code