shortest_path.m

this is a simple2-opt code

function [path,total_length,distances] = shortest_path(data_file,idx_initial_city)
% distances=distance(read_location_data(data_file));
distances=distance(data_file);
n=length(distances);
if nargin < 2
    idx_initial_city=ceil(rand(1)*n);
end
path=[];
outside=(1:n);
[path,outside]=add_to_path(path,outside,outside(idx_initial_city));
for i = 1:n-1
    entering_city=nearest_neighbor(distances,path(end),outside);
    [path,outside]=add_to_path(path,outside,entering_city);
end
total_length=total_length_of_cycle(distances,path);

function [path,outside] = add_to_path(path,outside,city)
path(end+1)=city;
outside(outside==city)=[];