Ho do I save the values of While at each hour?

For a while loop how I can calculate the values at each hour before do a break? As we know while loop only performs the condition statment and breaks the loop, then gives you the value at that specific hour only. I provide te example below :

for i=1:Time
    while water_tank_soc(i-1) < Water_tank_capacity_max  
        m_net_o(i) =.........
        m_net_i(i) = ......            
        % Update SOC
        water_tank_soc(i) = water_tank_soc(i-1) + m_net_i(i) - m_net_o(i);
        if water_tank_soc(i) >= Water_tank_capacity_max
            break
        end
        % Update for next time step
        water_tank_soc(i-1) = water_tank_soc(i); % Update previous state for next iteration
    end
end

[Walter Roberson]

That code appears to have the problem of water_tank_soc(i-1) not having been defined.

For the code to work,

water_tank_soc = zeros(1,Time-1);

would have to be executed first.

[Alhussain]

I don not have any problem here, what i give here is only a part of the full code. The problem is how to save the value at each iteration of the while loop

[dpb]

You would then have to doubly dimension the array and then the second dimension would have to be as wide as the maximum number of iterations or, the simpler would probably be to use a cell array at each hour to hold the iterations saving only the final as the double as present. The cell array can hold as many or as few as are in each hour.

[Alhussain]

Can you please show me an example on Matlab code

[dpb]

@Walter Roberson did for you...

Answer 1

[Umar]

Hi @ Alhussain,

To modify the simulation logic to track the hours taken for refilling until the tank reaches its maximum level, you need to increment a counter variable each hour the auxiliary pump operates. This counter will keep track of the total hours taken for the tank to refill from the minimum level to the maximum level.

% Initialize variables
tankLevel = 100; % Initial tank level
minLevel = 20; % Minimum tank level
maxLevel = 80; % Maximum tank level
hoursToRefill = 0; % Counter for hours taken to refill
% Simulate tank refilling process
while tankLevel < maxLevel
    if tankLevel <= minLevel
        % Refill tank using auxiliary pump
        tankLevel = tankLevel + 1; % Increment tank level
        hoursToRefill = hoursToRefill + 1; % Increment hours counter
    else
        % Normal operation
        tankLevel = tankLevel - 1; % Simulate tank consumption
    end
end
disp(['Tank refilled in ', num2str(hoursToRefill), ' hours.']);

So, as you can see the hoursToRefill variable keeps track of the total hours taken to refill the tank and while loop continues until the tank reaches the maximum level. During the refilling process, the hoursToRefill counter is incremented for each hour the auxiliary pump operates. Please let me know if you have any further questions.

Answer 2

[Walter Roberson]

Adjusted to save each iteration. A cell array is used because different iterations might run the while loop for different number of steps.

saved_soc = cell(1, Time);
for i=1:Time
    saved_soc{i} = water_tank_soc(i-1);
    while water_tank_soc(i-1) < Water_tank_capacity_max  
        m_net_o(i) =.........
        m_net_i(i) = ......            
        % Update SOC
        water_tank_soc(i) = water_tank_soc(i-1) + m_net_i(i) - m_net_o(i);
        if water_tank_soc(i) >= Water_tank_capacity_max
            break
        end
        % Update for next time step
        water_tank_soc(i-1) = water_tank_soc(i); % Update previous state for next iteration
        saved_soc{i}(end+1) = water_tank_soc(i-1};
    end
end

[Alhussain]

This is great Mr. Roberson but what I am doing is different. I have tried yoursbut this is only save the values for one hour. I want to you understand that I am doing hourly simulation of my code starting from 1 to 8760 and I have the refilling tank process so when the level of the tank reach to the minimum the auxilary pump start to operate to refill the tank untill reach to the maximum then stop, after that the process is normal. However, in my code when I am doing a while loop to refill the tank untill when it reach to the minimum then stop at the max. After the simulation the MAtlab only show m the auxilary pump refill the tank at one hour which is not correct it should give me the hours during refilling the tank untill reach to the maximum but this is happen to me because of the while loop which doing the iteration only for that hour.

[Walter Roberson]

No, the logic associated with saved_soc{i}(end+1) is saving every while loop iteration for every timestep, not just one hour.