# How can i save the variabels values as array form in for loop?

1 view (last 30 days)
yong -jun kim on 22 May 2022
Edited: TADA on 22 May 2022
How can i save the variabels values as array form in for loop?
I want to save 'Q' as array or matrix form
loop = 1;
i = 0;
for N = 0:150
i=i+0.05;
....
....
Q = N_cells*i*(E_nernst - V_out);
%'N_cells' is constant.
%E_nernst & V_out are function of 'i'
##### 1 CommentShowHide None
Rik on 22 May 2022
Something like Q(N+1)= instead of Q=?

TADA on 22 May 2022
Edited: TADA on 22 May 2022
You can define Q as a column/row vector. Its size can be set to the number of iterations you perform:
loop = 1;
i = 0;
maxN = 150;
N_cells = 10; % or the real constant value...
% This will preallocate the results as a column vector
% This bit is important for performance
% note that we add 1 to maxN because matlab has no index 0
Q = zeros(maxN+1, 1);
for N = 0:maxN
% if i isn't further changed in the loop body, you can also make i a
% function of N instead of defining it outside the loop as 0.
% something like: i = (N + 1) * 0.05;
% it won't improve performance nor save memory, its just more consice,
% and you don't need to move around the code to determine its value.
i=i+0.05;
%
% Real implementation goes here
%
E_nernst = sin(i);
V_out = exp(i);
% again, adding 1 to the current N, because indexing the zeroth
% position results in an error.
Q(N+1) = N_cells*i*(E_nernst - V_out);
end