If logic not working inside for loop

I am running a for loop which contains if/else logical statements. The code runs, but the results make it clear that the logic is not working correctly and the logical conditions are not being recognised. I'm not sure where I'm going wrong. The critical code is here, but the rest is attached.

    datetimeAS=[datetime(2012,7,1,0,0,0):minutes(30):datetime(2013,6,30,23,30,0)]';

    Demand = zeros(size(datetimeAS,1),1);
    Export = zeros(size(datetimeAS,1),1); 
    Solar = zeros(size(datetimeAS,1),1); 
    SOC = zeros(size(datetimeAS,1),1); 
    Battmax=zeros(size(datetimeAS,1),1);

   if ismember(i,index_15);
      AGSel= randperm(276,1);
      [AS1,AS2,AS3]= intersect(datetimeAS,Home.TimeStamp);
      Home3=zeros(size(datetimeAS));
      %creates a matrix to manage missing data
      Home3(AS2,1)=Home.Data(AS3,4);
      Solar=2*AusGrid2013(:,AGSel);
      LoadminPV = (Home3-2*AusGrid2013(:,AGSel));

      for k = 2:size(datetimeAS,1);
          % SOC=0 for k=1
          SOC1 = SOC(k-1); 
          NetLoad = LoadminPV(k);
          Battdisch = [SOC1 NetLoad maxdis];
          Battmax = SOCmax-SOC1;
          ExpBatt = -NetLoad;
          Battch = [Battmax ExpBatt];
          if NetLoad >= 0 ;%if net load is positive
              if SOC1 <= 0; %battery empty, draw from grid 
              Demand = NetLoad;
              SOC = 0;
              Export = 0;
              elseif SOC1 > 0; %battery is discharging
              Demand = NetLoad - min(Battdisch); 
              SOC = SOC1 - min(Battdisch);
              Export = 0;
              end
          elseif NetLoad < 0 ;%if PV is exporting
              if SOC1 >= SOCmax; %battery fully charged, export to grid
              SOC = SOC1;
              Demand = 0;
              Export = -NetLoad;
              elseif SOC1 < SOCmax; %battery is charging
              SOC = SOC1 + eff*min(Battch);
              Demand = 0;
              Export = (SOCmax-SOC1)-min(Battch);
              end
          end
      Demand(k,1)=Demand;
      SOC(k,1)=SOC;
      Export(k,1)=Export;
      end

I am trying to use Matlab to model the behaviour of households with battery storage and solar. There should be 4 potential states: the net load >0 and the battery is empty; the net load >0 and the battery has charge; the net load <0 and the battery is full; the net load <0 and the battery is charging. For the first few loops, it should be condition 1, net load >0 and empty battery, but it is not recognising this.

[Darshan Ramakant Bhat]

Can you please attach all the input (mat) files you are using it for this code? I am not able to run your code.

[Darshan Ramakant Bhat]

Also you can put break points just before the if-else statement and debug your code to see what is going wrong. Following documentation explains on how to use the debugger

https://www.mathworks.com/help/matlab/matlab_prog/debugging-process-and-features.html

[Sharon Young]

Thank you for your suggestion on where to put the break points. I had been trying to put them in the wrong place, and it hadn't been working.

I'm working with about 1GB of data, which exceeds the file size I can upload. I have attached a revised file which works with my data.

Answer 1

[Jan]

Please use Matlab's tools for an automatic indentation. Then the different levels of the IF conditions get clear immediatly.

You can be sure that the IF conditions are calculated accurately even inside a loop. This means, that the problem must be somewhere else. E.g.:

      Demand(k,1)=Demand;
      SOC(k,1)=SOC;
      Export(k,1)=Export;

This cannot run. As soon as e.g. Demand is a vector, you try to assign the complete vector to one of its elements. This must cause an error. If you do not get an error, you are running a different code.

Please post the code you are actually running. Perhaps you have stored multiple versions of the M-file and Matlab does not run the file you are expecting. This can be found out by the debugger easily: Set a breakpoint in the code and step through it line by line.

Note: If you have checked "if NetLoad >= 0" already, there is no need to check "elseif NetLoad < 0" again. A simple "else" is enough. At least, if the value of NetLoad is not NaN, but if this should be tested, better use isnan directly.

[Sharon Young]

Thank you for your time. As you say, the problem was not the IF conditions, which were correct. The code you nominated was part of the problem: I was not correctly saving the outputs from my loop. Attached is my updated code file. The corresponding data I am working with is too large to upload.

      for k = 2:size(datetimeAS,1);
          % SOC=0 for k=1
          SOC1 = SOC(k-1); 
          NetLoad = LoadminPV(k,1);
          Battdisch = [SOC1 NetLoad maxdis];
          Battmax = SOCmax-SOC1;
          ExpBatt = -NetLoad;
          Battch = [Battmax ExpBatt];
          if NetLoad >= 0 && SOC1 <= 0; %battery empty, draw from grid 
              Demand = NetLoad;
              SOC1 = 0;
              Export = 0;
          elseif NetLoad >= 0 && SOC1 > 0; %battery is discharging
              Demand = NetLoad - min(Battdisch); 
              SOC1 = SOC1 - min(Battdisch);
              Export = 0;
          elseif NetLoad < 0 && SOC1 >= SOCmax; %battery fully charged, export to grid
              SOC1 = SOC1;
              Demand = 0;
              Export = -NetLoad;
          elseif NetLoad < 0 && SOC1 < SOCmax; %battery is charging
              SOC1 = SOC1 + eff*min(Battch);
              Demand = 0;
  %             Export = (SOCmax-SOC1)-min(Battch);
                Export = -NetLoad-min(Battch);

          end

%      %save the results to use them!   
      Demand2(k,i)=Demand;
      SOC(k,i)=SOC1;
      Export2(k,i)=Export;
    end