Variable updated in for loop iteration

I have a very simple code that do not update the variable in the array during the for loop interation. It works if I run the for loop as i = 1. In that cas I can see that revenue(1) and budget_i(2) report the correct values. When the for loop interation exceed 1 interation, the arrays revenue and budget_i are no longer updated.

close = [0.01110 0.03600 0.01810 0.0208 ... 0.06470 0.00120]; % originally 126 values

revenue = zeros(1,126);

budget_i = zeros(1,126);

budget_i(1) = 100;

for i = 1

revenue(i) = budget_i(i) +(budget_i(i)*close(i));

if close(i) > 0

budget_i(i+1) = revenue(i) + 100;

elseif close(i) < 0

budget_i(i+1) = revenue(i) + 200;

end

end

%% here I have, correcly, budget_i(1) = 100; revenue(1) = 101.11; budget(2) = 201.11.

at this point I was expecting the revenue(2) calculation to work perfectly using budget_i(2) that I defined in the previous iteration but all I get in the variable array is a zero. Also revenue(1) is zero.

The code should work with for loop as for i = length(close) but revenue(i) and budget_i(i) failed to update and all I get is two arrays as revenue = zeros(1,126) and budget_i = zeros(1,126) with budget_i(1) = 100.

Any idea why it doesn't work at iteration greater than 1?

Answer 1

[Vilém Frynta]

I tested your code and revenue and budget_i were being updated.

I have no idea what the purpose of your script is, and thus I don't know you want to work with it, but if you were putting

for i = 2

then it didn't work. But if i input

for i = 1:2

then it works.

[Davide Frattini]

Very stupid mistake of mine in defining the iteration rule. Thanks a lot!