function ObjVal = objpush(Chrom,sswitch);
% 目標函數的維數
   Dim = 20;
% 初始值
   x0 = [0 0];

% 計算染色體參數
   [Nind,Nvar] = size(Chrom);

% 染色體檢查
   % 如果染色體為空，則定義邊界矩陣的大小和值
   if Nind == 0
      %返回輸出圖形的標題文字
      if sswitch == 2
         ObjVal = ['PUSH-CART PROBLEM-' int2str(Dim)];
      %返回全局最小值
      elseif sswitch == 3
         ObjVal = -(1/3 - ((3*Dim-1)/(6*Dim^2)) - (1/(2*Dim^3))*sum((1:Dim-1).^2));
      %定義邊界矩陣大小和值
      else   
         %變量的上下邊界        
         ObjVal = [0; 5];
         ObjVal = rep(ObjVal,[1 Dim]);
      end
   
   elseif Nvar == Dim
      ObjVal = zeros(Nind,1);
      X = rep(x0,[Nind 1]);
      for irun = 1:Nvar,
         Xsave = X;
         X(:,1) = Xsave(:,2);
         X(:,2) = 2 * X(:,2) - Xsave(:,1) + (1/Dim^2) * Chrom(:,irun);
      end
      X;
      ObjVal = -(X(:,1) - (1/(2*Dim)) * sum((Chrom.^2)')');
   %否則，染色體格式錯誤
   else
      error('size of matrix Chrom is not correct for function evaluation');
   end