MATLAB: Returning an additional value that is not part of the fitness function or objective for all population evaluation in GA

extra outputsgaGlobal Optimization Toolboxuseparallelusevectorized

Can anyone please help by showing the code how can I return an additional value (Sigma) that is not part of my fitness function (Mean). I know how to return all the populations, scores but I'm not sure how to return this additional value (sigma). I see many have asked this question but no one showed in a code rather than just directing us to use the nested functions. Here is my code: 
% the function to be optimized
 [objective]   = Optimization_Function(x,Pi,Pa,LogG,d,lifetime,Demand,BasePrice,HighPrice,...
  LowPrice,dis_rate_lamda,Geo,Wells_cost,Wells_rate,DStage,Operating_Fields,row,Amt,FOPEX,VOPEX)
.
.
.
.
expectedNPV  = mean(NPV_C);
sigma        = std(NPV_C); %%%%% I need this value for every population evaluation 
NewObjective = (expectedNPV)
objective    = - NewObjective; 
% my optimization code 
clear gaoutfunction
options          = optimoptions('ga','OutputFcn',@gaoutfunction,'UseParallel',true);
startTime        = tic;
fun              = @(x)Optimization_Function(x,Pi,Pa,LogNormal_G,d_cline,lifetime,Demand,BasePrice,...
    HighPrice,LowPrice,dis_rate_lamda,Geo,Wells_cost,Wells_rate,DStage,Operating_Fields,row,Amt,FOPEX,VOPEX);  
[xGA,fval]       = ga(fun,nvars,[],[],[],[],lowbond,upbond,[],[],options);
time_ga_parallel = toc(startTime);
record                = gaoutfunction();
gapopulationhistory   = vertcat(record.Population);
gabesthistory         = vertcat(record.Best);
gascorehistory        = vertcat(record.Score);
Results               = [gapopulationhistory gascorehistory];
% my output funciton which includes populations, scores but does not include sigma :(
function [state,options,optchanged] = gaoutfunction(options,state,flag)
    persistent state_record 
    if isempty(state_record)
      state_record = struct('Population', {}, 'Best', {}, 'Score', {});
    end
    if nargin == 0
      state = state_record;
      options = [];
      optchanged = [];
    else
      state_record(end+1) = struct('Population', state.Population, 'Best', state.Best', 'Score', state.Score);
      optchanged = false;
    end
end
Can anyone please show me how to return sigma as I’m returning all the populations and their scores. Please note the score here is only the objective which is the mean. The sigma value is not part of the optimization but I need it to save the time rather than running the model again to evaluate it. Please help.

Best Answer

function run_optimization
    allSigmas=[];
    [xGA,fval]   = ga(fun,nvars,[],[],[],[],lowbond,upbond,[],[],options);
    
    
     % the function to be optimized
    function  [objective]   = Optimization_Function(x,Pi,Pa,...)        .
                     ....
                         
           objective    = - NewObjective; 
          allSigmas(end+1)      = std(NPV_C); %%%%% I need this value for every population evaluation 
        
    end
end
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