Generate an iteration to determine the characteristic polynomial of several matrices

Hello, I need a code that through the for will iteratively give me the characteristic polynomial of the 7 matrices that I have, the problem is that I want them to be called one at a time for each iteration, that is, in iteration 1, in the function poly between matrix A1, on iteration 2 in the poly function between matrix A2, and so on. For this reason, it occurred to me to put poly (Ai) because the number of each iteration is the same as the matrix that I need it to enter, but obviously matlab thinks that I am asking for the polynomial of the variable Ai. What can I do to solve my problem? Thanks in advance.

A1=[1 2; 2 1], A2=[1 -2; 2 1], A3=[2 1; 0 2]
A4=[2 2; 2 2], A5=[1 1 0; 0 -2 1; 0 0 2]
A6=[2 1 0; 1 2 0; 0 0 -1], A7=[2 0 0; 1 2 0; 0 0 -1]
for i=1:7
    poly(Ai)
end

Answer 1

[John D'Errico]

What can you do? Learn to use MATLAB properly.

Here, that means to learn to use matrices and arrays, especially cell arrays.

A={[1 2; 2 1], [1 -2; 2 1], [2 1; 0 2], [2 2; 2 2],...
   [1 1 0; 0 -2 1; 0 0 2],[2 1 0; 1 2 0; 0 0 -1],[2 0 0; 1 2 0; 0 0 -1]};

A is a cell array. You index into A using curly braces. A has 7 elements.

for i=1:7
    poly(A{i})
end

ans = 1×3

1 -2 -3

ans = 1×3

1.0000 -2.0000 5.0000

ans = 1×3

1 -4 4

ans = 1×3

1 -4 0

ans = 1×4

1 -1 -4 4

ans = 1×4

1 -3 -1 3

ans = 1×4

1 -3 0 4

[Felipe Álvarez Acevedo]

Hello, thank you very much, but is it possible to do something without having to create the cell array?

[John D'Errico]

I'm sorry. You want me to teach you to write some code that is far more poor, so that you can avoid having to learn MATLAB? In fact, no, you cannot simply create and index named arrays like that at all easily. And what you could do (code that I won't tell you how to write) would look far more nasty than simply creating a cell array.

[Walter Roberson]

http://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval