为什么这段代码的结果没有给最后一个个体赋予帕累托前沿编号：function [F,ndx] = fast_nondominated_sort(objectives) % obj为目标函数值矩阵，每行代表一个个体的目标函数值向量 % F为快速非支配排序后的结果，每个元素代表一个帕累托前沿 % ndx为每个个体所属的帕累托前沿编号 [n,~] = size(objectives); F = cell(1,n); S = cell(1,n); nPoints = zeros(1,n); for i = 1:n S{i} = []; nPoints(i) = 0; for j = 1:n if isdominated(objectives(i,:),objectives(j,:)) S{i} = [S{i} j]; elseif isdominated(objectives(j,:),objectives(i,:)) nPoints(i) = nPoints(i) + 1; end end if nPoints(i) == 0 F{1} = [F{1} i]; end end iFront = 1; while ~isempty(F{iFront}) Q = []; for i = F{iFront} for j = S{i} nPoints(j) = nPoints(j) - 1; if nPoints(j) == 0 Q = [Q j]; ndx(j) = iFront + 1; end end end iFront = iFront + 1; F{iFront} = Q; end end，请给出修改后的代码示例

修改后的代码如下所示：

function [F,ndx] = fast_nondominated_sort(objectives)
% obj为目标函数值矩阵，每行代表一个个体的目标函数值向量
% F为快速非支配排序后的结果，每个元素代表一个帕累托前沿
% ndx为每个个体所属的帕累托前沿编号

[n,~] = size(objectives);

F = cell(1,n);
S = cell(1,n);
nPoints = zeros(1,n);
ndx = zeros(1,n); % 添加此行代码，将 ndx 初始化为全 0

for i = 1:n
    S{i} = [];
    nPoints(i) = 0;
    
    for j = 1:n
        if isdominated(objectives(i,:),objectives(j,:))
            S{i} = [S{i} j];
        elseif isdominated(objectives(j,:),objectives(i,:))
            nPoints(i) = nPoints(i) + 1;
        end
    end
    
    if nPoints(i) == 0
        F{1} = [F{1} i];
        ndx(i) = 1; % 添加此行代码，将第一个帕累托前沿的个体编号 ndx 设为 1
    end
end

iFront = 1;

while ~isempty(F{iFront})
    Q = [];
    
    for i = F{iFront}
        for j = S{i}
            nPoints(j) = nPoints(j) - 1;
            
            if nPoints(j) == 0
                Q = [Q j];
                ndx(j) = iFront + 1;
            end
        end
    end
    
    iFront = iFront + 1;
    F{iFront} = Q;
end

end

修改后的代码在初始化 `ndx` 时将其全部赋值为0，并在第一个帕累托前沿的个体中将其相应的 `ndx` 设为1，以确保在循环结束时所有个体都被赋予了帕累托前沿编号。