MatingPool.m

function MatingPool = MatingPool(Population,Archive,N)
% MATINGPOOL 产生更多可行解
  MatingPool = [];
   
  if length(Archive)<N
      PopAll = [Population,Archive];
      [~,b]=unique(PopAll.objs,'rows');
      PopAll = PopAll(1,b);
      SelectedIndex= TournamentSelection(2,N,sum(PopAll.objs,2),DensityCal(PopAll.decs));
      MatingPool= PopAll(SelectedIndex);
  else
      AllPop = [ Population,Archive];
      Zmin   = min(AllPop.objs,[],1);
      PopObj = (AllPop.objs-repmat(Zmin,length(AllPop.objs),1))./(repmat(max(AllPop.objs),length(AllPop.objs),1)-repmat(Zmin,length(AllPop.objs),1)+1e-10)+1e-10;
      Cosine = 1 - pdist2(PopObj,PopObj,'cosine');
      Cosine = Cosine.*(1-eye(size(PopObj,1)));

      Temp     = sort(-Cosine,2);
      [~,Rank] = sortrows(Temp);

      CV1 = sum(max(0,Population.cons),2);
      CV2 = sum(max(0,Archive.cons),2);

      Angle1 = Rank(1:N);
      Angle2 = Rank(N+1:length(AllPop));

      Index1 = randi(N,1,N);
      Index2 = randi(length(Archive),1,N);

      i = 0;
      while length(MatingPool) < N
          if CV1(Index1(i+1)) < CV2(Index2(i+1))
              MatingPool = [MatingPool,Population(Index1(i+1))];
          else
              MatingPool = [MatingPool,Archive(Index2(i+1))];
          end
          if Angle1(Index1(i+2)) < Angle2(Index2(i+2))
              MatingPool = [MatingPool,Population(Index1(i+2))];
          else
              MatingPool = [MatingPool,Archive(Index2(i+2))];
          end
          i = i + 2;
      end
  end
end

function Density = DensityCal(PopObj)
     [N,~] = size(PopObj);  
    Zmin       = min(PopObj,[],1);
    PopObj = (PopObj-repmat(Zmin,N,1))./(repmat(max(PopObj),N,1)-repmat(Zmin,N,1)+1e-20);
    Distance = pdist2(PopObj,PopObj);
    Distance(logical(eye(length(Distance)))) = Inf;
    DistanceSort = sort(Distance,2);
    Density = 1./(1+DistanceSort(:,floor(sqrt(length(Distance)))+1));  
 end