www.pudn.com > NSGAII.rar > replace_chromosome.m, change:2008-11-26,size:1978b

```rfunction f  = replace_chromosome(intermediate_chromosome,pro,pop)
%% replace_chromosome(intermediate_chromosome,pro,pop)
% This function replaces the chromosomes based on rank and crowding
% distance. Initially until the population size is reached each front is
% added one by one until addition of a complete front which results in
% exceeding the population size. At this point the chromosomes in that
% front is added subsequently to the population based on crowding distance.

[N,V] = size(intermediate_chromosome);
switch pro
case 1
M = 2;
V = 6;
case 2
M = 3;
V = 12;
end

% Get the index for the population sort based on the rank
[temp,index] = sort(intermediate_chromosome(:,M + V + 1));

% Now sort the individuals based on the index
for i = 1 : N
sorted_chromosome(i,:) = intermediate_chromosome(index(i),:);
end

% Find the maximum rank in the current population
max_rank = max(intermediate_chromosome(:,M + V + 1));

% Start adding each front based on rank and crowing distance until the
% whole population is filled.
previous_index = 0;
for i = 1 : max_rank
current_index = max(find(sorted_chromosome(:,M + V + 1) == i));
if current_index > pop
remaining = pop - previous_index;
temp_pop = ...
sorted_chromosome(previous_index + 1 : current_index, :);
[temp_sort,temp_sort_index] = ...
sort(temp_pop(:, M + V + 2),'descend');
for j = 1 : remaining
f(previous_index + j,:) = temp_pop(temp_sort_index(j),:);
end
return;
elseif current_index < pop
f(previous_index + 1 : current_index, :) = ...
sorted_chromosome(previous_index + 1 : current_index, :);
else
f(previous_index + 1 : current_index, :) = ...
sorted_chromosome(previous_index + 1 : current_index, :);
return;
end
previous_index = current_index;
end```