How to run the following codes.

what is error in following codes

for i=1:12

if i = 12

x1 = 9

end

x1 = [1];

x2 = [3];

x1(i) = x1(i-1) - x2;

x = [x1 x2]

end

When i run it it shows following error please help me to solve error.

Array indices must be positive integers or logical values.

Answer 1

[Matt Gaidica]

MATLAB uses one-based indexing. Therefore, in your code, on the first iteration where i = 1, the line marked is trying to index x1 at the zero position:

for i = 1:12
    if i == 12
        x1 = 9
    end    
    x1 = [1];
    x2 = [3];
    x1(i) = x1(i-1) - x2; % <-- error here
    x = [x1 x2]
end

There are still issues with your code, but it's hard to know what the fix is without more context. Also, note that i is reserved as an imaginary number in MATLAB, so it's recommended to use ii or another variable as your iterator.

[Usman Taya]

Here is my actual code and when i run it than it show error as above i mention.

x4 = [0,0,0,0,0,0,0,0,0,0,20.10,386.22,1013.36,1688.74,2685.19,2905.13,3370.94,3730.35, 2232.83,4166.60,4404.63,4853.86,4953.58,3897.27,2996.94,4328.13,4293.91,3655.74,3593.10,3080.08,2633.71,2058.05,1374.24,697.60,213.83,41.52,0,0,0,0,0,0,0,0,0,0,0,0];

x5 = [3498.91,3506.20,3491.12,3515.54,3490.08,3546.83,3491.12,3631.95,3895.54,3647.16,3498.37,3548.29,3525.54,3415.20,3394.50,3426.41,3413.20,3409.79,6531.87,6317.20,6433.33,6075.83,5983.62,5525.04,5650,5276.16,5885.04,5169.33,5908.37,5376.66,5733.37,5243.58,5792,5384.25,5408.95,5408.66,3662.29,3701.54,3688.41,3648.87,3648.58,3594.5,3521.12,3653.87,3771.70,3767.20,3541.04,3532.16];

E_batt_inst = 80000;

x3Max = 72000;

x3Min = 8000;

x2Min = -5000;

x2Max = 5000;

x1Min = 0;

x1 = zeros(48,1);

x2 = zeros(48,1);

x3 = zeros(48,1);

for t = 1:48

if t<14 && t>40

x1Max = 4500;

elseif t>14 && t<=40

x1Max = 3000;

end

if t==1

x3 = 40000;

flag = 1;

end

if x1(t)>x1Max

x1(t) = x1Max;

elseif x1(t)<x1Min

x1(t) = x1Min;

end

if x2(t)>x2Max

x2(t) = x2Max;

elseif x2(t)<x2Min

x2(t) = x2Min;

end

if x3(t)>x3Max

x3(t) = x3Max;

elseif x3(t)<x3Min

x3(t) = x3Min;

end

if (flag == 1)&&(x3 <= 8000)

x2(t)= x5(t) - x4(t)

elseif x2(t)< x5(t) - x4(t)

x1(t)= x5(t) - x4(t) - x2(t)

y = t-1;

x3(t) = x3(y) - (x2(t)/E_batt_inst);

flag = 1;

elseif (x3 >= 72000)

flag = 0;

x2(t)= x5(t) - x4(t)

elseif x2(t)< x5(t) - x4(t)

x1(t)= x5(t) - x4(t) - x2(t)

y = t-1;

x3(t) = x3(y) - (x2(t)/E_batt_inst);

end

end

Here x1, x2 and x3 is measured by given equation. x2 is power of battery which is charging and dischargine with respect to maximum and minimum capacity (x3) of battery. x1 is power imported from diesel generator. Battery is not allowed to discharge when its charged and flag = 1. When charging than battery power is in negative (-5000 (x2Min)) while discharge it is positive (5000 (x2Max)). If you want further details than please share your email address so I can email u. or please send me email on [e-mail]