For loop doesn't run properly

I coded this myself to plot a graph of digging time vs amount of gold in the bucket for each specific depth. Everything seemed to work fine and there are no errors but the for loop doesn't run properly. Even though n updates each iteration from 2 to 8 the final answer I get is always for n = 2. However, when I don't use for loop and specify n = 2, 3, 4, etc. the code works fine and returns the actual solution I want. I know there could be 1 tiny silly mistake somewhere that is causing this problem, but I've been staring at this for almost 3 hours and still have no clue. Can someone help please.

load = 0; 
sluice_time = 2*((20/1)/60); 
dig_time = 0; 
tot_time = 0;
bucket = 0;  
shovel = 6;  
tot_gold = 0; 
% New:
gold_avg3 = []; % A new empty vector for the average gold in the bucket for each depth 
gold_vector3 = []; % A new empty vector for totol gold in the bucket for b(iii)
for n = 2:8
    i = 1; 
    d = 1;
    while tot_time < 239.999    
        while load < 18
            if d == n % When the depth is at the particular depth we want
            load = load + 3; 
            dig_time = dig_time + 1;
            tot_gold = tot_gold + gold(n); % Only takes the shovel load from a particular depth therefore the amount of gold is the same 
            gold_vector3(i) = tot_gold;
            i = i+1;  
            d = 1; % After we took the gold at that specific level of depth, we have to go back to the surface and repeat the same process again
            else
            dig_time = dig_time + 1; % Dig time increases regardless of whether we put the shovel load into the bucket or not
            gold_vector3(i) = tot_gold; % while we're digging at a depth that we're not interested, the amount of gold in the bucket remains the same
            i = i+1;
            d = d+1; % If the depth is not the depth we're interested in, move on to the next depth
            end
        end
        tot_time = tot_time + dig_time + sluice_time;
        dig_time = 0; 
        load = 0; 
        tot_gold = 0; 
        bucket = bucket + 1; 
        tot_dig_time = (1:bucket*6*n); % The total dig time now would be 6n per bucket, where n is the particular depth (Ie. level 2 for 12 min, level 3 for 18 min etc.)
    end
gold_avg3(n) = sum(gold_vector3)/bucket; % Assign the nth element to the tot_gold of that nth iteration
plot(tot_dig_time,gold_vector3) % Plot the new scenario
hold on
end

[Mathieu NOE]

hello

tried to run your code but got this error message (gold(n) is undefined) :

Unrecognized function or variable 'gold'.

Error in Stanley (line 33)

tot_gold = tot_gold + gold(n); % Only takes the shovel load from a particular depth

therefore the amount of gold is the same

Answer 1

[Jan]

tot_time = 0;
for n = 2:8
    while tot_time < 239.999    
        while load < 18
            if d == n % When the depth is at the particular depth we want
            else
            end
        end
        tot_time = tot_time + dig_time + sluice_time;
    end
end

After the first iteration of the for n loop, tot_time is >= 239.999 and it is not changed again. Therefore the inner loop is not entered anymore.

You can check this problems using the debugger. Set a breakpoint in your code and step through it line by line.

[Stanley Ka]

I found the problem, I just needed to reset gold_vector3 and changed the vector length for tot_time in plot and it worked perfectly

Thanks so much for pointing out the error