What changes do i need to make so my matrix is not overwritten?

I have the following code it runs fine, note where i=1; i want to change it to i=1:3, but i want to store the individual 3 matrices separately. What changes should i make?

Z=ones(n,no_of_stages);
for i=1;
    for k=1:no_of_stages
        M(k,k)=diag(-phi(i,k));
        for d=2:no_of_stages
        M(d,d-1)=diag(abs_coeff(i,d));
            for r=1:no_of_stages-1;
        M(r,r+1)=diag(Z(i,r));
            end
        end
    end    
end

Answer 1

[Walter Roberson]

Use a cell array indexed by i

[A K]

The code creates a tri-diagonal matrix, do u mean i should ad another line saying M(i)=M??? so M(1) is the first matrix, M(2) is the second.

[Walter Roberson]

Z=ones(n,no_of_stages);
for i=1;
    clear tM
    for k=1:no_of_stages
        tM(k,k)=diag(-phi(i,k));
        for d=2:no_of_stages
            tM(d,d-1)=diag(abs_coeff(i,d));
            for r=1:no_of_stages-1;
                tM(r,r+1)=diag(Z(i,r));
            end
        end
    end
    M{i} = tM;   
end