这段代码function parent =select_parents(population, population_size,F,crowding_distance) fronts = F; crowdingDist = crowding_distance; newpop = []; frontIndex = 1; while size(newpop, 1) + size(fronts{frontIndex}, 1) <= population_size [~, sortIndex] = sort(crowdingDist(fronts{frontIndex}), 'descend'); sortedFront = fronts{frontIndex}(sortIndex, :); newpop = [newpop; population(sortedFront, :)]; frontIndex = frontIndex + 1; end if size(newpop, 1) < popsize [~, sortIndex] = sort(crowdingDist(fronts{frontIndex}), 'descend'); sortedFront = fronts{frontIndex}(sortIndex, :); n = population_size - size(newpop, 1); newpop = [newpop; population(sortedFront(1:n), :)]; end parents = newpop; end报错为：Index in position 1 exceeds array bounds. Index must not exceed 1. 出错 select_parents (第 8 行) sortedFront = fronts{frontIndex}(sortIndex, :);如何修改

这个错误通常是因为 `fronts` 这个 cell 数组的某个元素是一个空数组，导致 `sortIndex` 排序后的索引超过了空数组的索引范围，需要在函数中添加一些判断来避免这种情况发生。

你可以在第 6 行添加以下代码来判断当前 front 是否为空：

while size(newpop, 1) + size(fronts{frontIndex}, 1) <= population_size && ~isempty(fronts{frontIndex})

然后在第 11 行添加以下代码来判断最后一个 front 是否为空：

if ~isempty(fronts{frontIndex})
    [~, sortIndex] = sort(crowdingDist(fronts{frontIndex}), 'descend');
    sortedFront = fronts{frontIndex}(sortIndex, :);
    n = population_size - size(newpop, 1);
    newpop = [newpop; population(sortedFront(1:n), :)];
end

这样就可以避免出现空数组的问题了。