make a column matrix with outputs of a for loop

I have a for loop and I want the outputs of each iteration to sit in a column matrix. for example i have the code below:

for i=1:5
 a=[1 2; i 3]
[P,Q]=eig(a);
end

for the first iteration Q(i=1)=[0.2679 0; 0 3.731], for second iteration I have Q(i=2)=[-0.2361 0; 0 4.2361] and so on. I want to construct a 10*1 column matrix in which all the outputs are after each other like this:

S=[0.2679 3.731 -0.2361 4.2361 ....]

but I really don't know how. it would be appreciated if u help me.

[Mathieu]

So you want to concatenate some vectors? Because if yes:

b = [];
for i=1:1:5
a = [1 2]
b = [b a];
end

And the result is a vector with [1 2 1 2 1 2 1 2 1 2] (5 times the vector a)

Answer 1

[David Schubert]

Use diag(Q) to obtain only the eigenvalues on the diagonal of Q, and then concatenate:

mat = [];
for i=1:5
    a=[1 2; i 3];
    [P,Q]=eig(a);
    mat = [mat; diag(Q)];
end