How to do counter in matlab?

I want to do just like the following Matlab, it returns error, how to fix it so Matlab can take it without errors?

    load M.dat
    t = 600;
    q(1)=[1;0;0;0;0;0;0;0;0;0];
    for i=1:t-1,
        q(i+1) = q(i)*M;
    end

I want to have qt in the end. q(1) is a matrix called q1, and I want q2 which is q(i+1) to be M*q1 , and q3 to be M*q2 and visa versa until we reach qt

[James Tursa]

What is M? A matrix or a scalar?

[Hello Matlab]

A matrix

[James Tursa]

Then q(i)*M is scalar*matrix, which is a matrix. How do you expect to store this into q(i+1), which is a scalar? You need to examine your equations and correct them to something that makes sense.

[Hello Matlab]

I edit the question, I hope it makes sense now!!!

Answer 1

[Image Analyst]

You can't assign a 10-element column vector to a single element of q. Only one element can go into the first element of q, not 10.

[Hello Matlab]

This is not to determine the elements, this is a matrix called q0, and I want q1 to be M*q0 , and q2 to be M*q1 and visa versa until we reach qt.

[Image Analyst]

Try this:

M = 100 % Whatever...
t = 600;
q = zeros(1, t);
q(1)= 1;
for i=1:t-1,
    q(i+1) = q(i)*M;
end

Answer 2

[James Tursa]

I am still guessing here. Maybe this is what you want? (I am assuming M is square)

    load M.dat
    t = 600;
    q = zeros(size(M,1),t);
    q(1,1) = 1;
    for k=2:t,
        q(:,k) = M * q(:,k-1);
    end

Each column of q is an intermediate answer, with q(:,t) being your final answer.

If you don't need all the intermediate answers, then simply

    load M.dat
    t = 600;
    q1 = zeros(size(M,1),1);
    q1(1) = 1;
    qt = M^(t-1) * q1;

Answer 3

[ALEX]

Hello,

Play around with this, let me know if you have problems.

clear all M = 1.1; t = 600; q1 = zeros(10,1); q1(1)= 1;

val = q1*M;

for i=1:t-1

    eval(['q' num2str(i+1) '   = val ']);
    val = val*M;
end

Peace

[James Tursa]

Read this link to see why creating hundreds of variables q1, q2, ... etc in a loop is generally very bad programming practice:

http://www.mathworks.com/matlabcentral/answers/143-how-do-i-make-a-series-of-variables-a1-a2-a3-a10

[Stephen23]

Read these to know why this answer will force you into writing slow, complex, buggy code:

https://www.mathworks.com/help/matlab/matlab_prog/string-evaluation.html

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