Loops: savings, creating vectors, for-loop, if-else

You have 2000$ on a bank account. Annual interest is 7%, and when the savings reach 10000$, the annual interest rise to 9%.

Saving time 30 years.

Variable balanceV must be of size [31 3], but with script below you got [1 1].

How do I collect the data from the loop in one vector size of [31 3]?

balanceV = 2000;

r1 = 0.07; %Interest rate when under 10000

r2 = 0.09; %Interest rate when over 10000

years = 30;

for y = 1:years

balanceV = balanceV * (1+r1);

if balanceV < 10000;

r1 = r1;

else

r1 = r2;

end

end

Answer 1

[azarang asadi]

You haven't clearly expressed what you are trying to save in the for loop. [31 3] this means 3 variables saved with 31 iterations in the for loop so I assumes as you only have balanceV and r1 and r2 in the for loop, those are the variables you need to save, so first column corresponds to balanceV, second to r1 and third to r2:

balanceV = 2000;
r1 = 0.07;      %Interest rate when under 10000
r2 = 0.09;      %Interest rate when over 10000
years = 30;
storage = zeros(31,3); % the first column of this is balanceV, second is r1 and third is r2.
storage(1,1) = balanceV;
storage(1,2) = r1;
storage(1,3) = r2

for y = 2:years  % start from 2 as the first row is already filled for the initialized values.
    balanceV = balanceV * (1+r1);
    if balanceV < 10000;
        r1 = r1;
    else
        r1 = r2;
    end
    storage(y,1) = balanceV;
    storage(y,2) = r1;
    storage(y,3) = r2;
end