How do I save values in my loop as a column vector?

I have a loop and I need to save two values (h and err_max) from it into a column vector so that I can make a table. I have been using ' after the variable to transpose the vector so that my table works, but this sometimes causes issues when running the whole file because of other sections i have written. Is there a way to save values from a loop into a column vector without using '?

Side note: My value sol2 saves as a column vector by using sol2(k, : ) but I have tried this on h and it creates a big matrix instead.

I will copy my code here:

for i = 1:16
    h = 2^-(i+1);
    N = 4/h;
    % Initialise variables
    k = 0;
    sol2 = 0;
    for t = 0:h:4
        k = k + 1;
        sol2(k,:) = 2*(t) - exp(t);
    end
    w=Euler(a,b,N,alpha,f);
    err_ = sol2 - w;
    err_abs = abs(err_);
    err_max(i) = max(err_abs);
    h1(i) = h;
end
 
table(h1', err_max')

[Francesca Maher]

Also, just to add: my code isn't running correctly at the moment for err_max

Answer 1

[Robert]

You can define the variables as columns before your for-loop:

h1 = zeros(16, 1);
err_max = zeros(16, 1);

By then assigning values to it, the variables remain columns.

[Francesca Maher]

Thank you! Code now runs how I want it to

Answer 2

[Peng Li]

You can use h1(:) instead to make hi1 explicitely a column vector. This has a potential risk too if you h1 is actually a matrix as it will force it to reshape to a column vector.

For your code, what is your w like? no idea about your a, b, alpha, f variables.

Your outerloop is not necessary and can be optimized. Or at least, to improve efficiency, you'd better reallocate space for those variables that change size with loop.