hintializing variables with different numbers and saving them in a matrix

Hi,

I have a question about initializing variables that contain different numbers in a matrix.

For example,

I want to obtain matrix V by using while loop:

V = [V1;V2;V3.....;Vn].

Instead of manually writing V1, V2, V3 .. in matrix V, I want it to be done by using a loop!

Thank you.

Answer 1

[Jan]

This is asked daily for many years now. See:

• https://www.mathworks.com/matlabcentral/answers/57445-faq-how-can-i-create-variables-a1-a2-a10-in-a-loop
• https://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval

The answer is always the same: Don't do this. Create an array instead and use the numbers as indices. This is faster, nicer, more flexible, easier to debug, to maintain, to expand and to read.

V = zeros(1, n);  % For scalars
m = 7;
M = zeros(m, n);  % For column vectors
C = cell(1, n);   % For variables with different sizes
for k = 1:n
  V(k)    = k ^ 2;
  M(:, k) = rand(m, 1);
  C{k}    = sprintf('%g', k);
end

[Sara Al Shamsi]

Thank you.