/// <summary>
/// Draw just the list of cities.
/// </summary>
/// <param name="cityList">The list of cities to draw.</param>
private void DrawCityList(Cities cityList)
{
Image cityImage = new Bitmap(tourDiagram.Width, tourDiagram.Height);
Graphics graphics = Graphics.FromImage(cityImage);
if (pic_d)
{
graphics.DrawImage(pic, ulCorner);
}
foreach (City city in cityList)
{
// Draw a circle for the city.
graphics.DrawEllipse(Pens.Red, city.Location.X - 2, city.Location.Y - 2, 5, 5);
}
this.tourDiagram.Image = cityImage;
updateCityCount();
}
/// <summary>
/// Draw just the list of cities.
/// </summary>
/// <param name="cityList">The list of cities to draw.</param>
private void DrawCityList(Cities cityList)
{
Image cityImage = new Bitmap(tourDiagram.Width, tourDiagram.Height);
Graphics graphics = Graphics.FromImage(cityImage);
int City_num = 1;
foreach (City city in cityList)
{
// Draw a circle for the city.
graphics.DrawString(City_num.ToString(), drawFont, drawBrush, city.Location.X + 3, city.Location.Y + 3);
graphics.DrawEllipse(Pens.Black, city.Location.X - 2, city.Location.Y - 2, 5, 5);
City_num += 1;
}
this.tourDiagram.Image = cityImage;
updateCityCount();
}
/// <summary>
/// Determine fitness
/// </summary>
public void DetermineFitness(Cities cities)
{
Fitness = 0;
int lastCity = 0;
int nextCity = this[0].Connection1;
foreach (Link link in this)
{
Fitness += cities[lastCity].Distances[nextCity];
if (lastCity != this[nextCity].Connection1)
{
lastCity = nextCity;
nextCity = this[nextCity].Connection1;
}
else
{
lastCity = nextCity;
nextCity = this[nextCity].Connection2;
}
}
}
/// <summary>
/// Perform the crossover operation on 2 parent tours to create a new child tour.
/// This function should be called twice to make the 2 children.
/// In the second call, the parent parameters should be swapped.
/// </summary>
/// <param name="parent1">The first parent tour.</param>
/// <param name="parent2">The second parent tour.</param>
/// <param name="cityList">The list of cities in this tour.</param>
/// <param name="rand">Random number generator. We pass around the same random number generator, so that results between runs are consistent.</param>
/// <returns>The child tour.</returns>
public static Tour Crossover(Tour parent1, Tour parent2, Cities cityList, Random rand)
{
Tour child = new Tour(cityList.Count); // the new tour we are making
int[] cityUsage = new int[cityList.Count]; // how many links 0-2 that connect to this city
int city; // for loop variable
int nextCity; // the other city in this link
for (city = 0; city < cityList.Count; city++)
{
cityUsage[city] = 0;
}
// Take all links that both parents agree on and put them in the child
for (city = 0; city < cityList.Count; city++)
{
if (cityUsage[city] < 2)
{
if (parent1[city].Connection1 == parent2[city].Connection1)
{
nextCity = parent1[city].Connection1;
if (testConnectionValid(child, cityList, cityUsage, city, nextCity))
{
joinCities(child, cityUsage, city, nextCity);
}
}
if (parent1[city].Connection2 == parent2[city].Connection2)
{
nextCity = parent1[city].Connection2;
if (testConnectionValid(child, cityList, cityUsage, city, nextCity))
{
joinCities(child, cityUsage, city, nextCity);
}
}
if (parent1[city].Connection1 == parent2[city].Connection2)
{
nextCity = parent1[city].Connection1;
if (testConnectionValid(child, cityList, cityUsage, city, nextCity))
{
joinCities(child, cityUsage, city, nextCity);
}
}
if (parent1[city].Connection2 == parent2[city].Connection1)
{
nextCity = parent1[city].Connection2;
if (testConnectionValid(child, cityList, cityUsage, city, nextCity))
{
joinCities(child, cityUsage, city, nextCity);
}
}
}
}
// The parents don't agree on whats left, so we will alternate between using
// links from parent 1 and then parent 2.
for (city = 0; city < cityList.Count; city++)
{
if (cityUsage[city] < 2)
{
if (city % 2 == 1) // we prefer to use parent 1 on odd cities
{
nextCity = findNextCity(parent1, child, cityList, cityUsage, city);
if (nextCity == -1) // but if thats not possible we still go with parent 2
{
nextCity = findNextCity(parent2, child, cityList, cityUsage, city);;
}
}
else // use parent 2 instead
{
nextCity = findNextCity(parent2, child, cityList, cityUsage, city);
if (nextCity == -1)
{
nextCity = findNextCity(parent1, child, cityList, cityUsage, city);
}
}
if (nextCity != -1)
{
joinCities(child, cityUsage, city, nextCity);
// not done yet. must have been 0 in above case.
if (cityUsage[city] == 1)
{
if (city % 2 != 1) // use parent 1 on even cities
{
nextCity = findNextCity(parent1, child, cityList, cityUsage, city);
if (nextCity == -1) // use parent 2 instead
{
nextCity = findNextCity(parent2, child, cityList, cityUsage, city);
}
}
else // use parent 2
{
nextCity = findNextCity(parent2, child, cityList, cityUsage, city);
if (nextCity == -1)
{
nextCity = findNextCity(parent1, child, cityList, cityUsage, city);
}
}
if (nextCity != -1)
{
joinCities(child, cityUsage, city, nextCity);
}
}
}
}
}
// Remaining links must be completely random.
// Parent's links would cause multiple disconnected loops.
for (city = 0; city < cityList.Count; city++)
{
while (cityUsage[city] < 2)
{
do
{
nextCity = rand.Next(cityList.Count); // pick a random city, until we find one we can link to
} while (!testConnectionValid(child, cityList, cityUsage, city, nextCity));
joinCities(child, cityUsage, city, nextCity);
}
}
return(child);
}
/// <summary>
/// Starts the TSP algorithm.
/// To stop before all generations are calculated, set <see cref="Halt"/> to true.
/// </summary>
/// <param name="populationSize">Number of random tours to create before starting the algorithm.</param>
/// <param name="maxGenerations">Number of times to perform the crossover operation before stopping.</param>
/// <param name="groupSize">Number of tours to examine in each generation. Top 2 are chosen as the parent tours whose children replace the worst 2 tours in the group.</param>
/// <param name="mutation">Odds that a child tour will be mutated..</param>
/// <param name="iterationForConverge">Iteration for converge...</param>
/// <param name="seed">Seed for the random number generator.</param>
/// <param name="chanceToUseCloseCity">The odds (out of 100) that a city that is known to be close will be used in any given link.</param>
/// <param name="cityList">List of cities in the tour.</param>
public void Begin(int populationSize, int maxGenerations, int groupSize, int mutation, int iterationForConverge, int seed, int chanceToUseCloseCity, Cities cityList)
{
rand = new Random(seed);
this.cityList = cityList;
population = new Population();
population.CreateRandomPopulation(populationSize, cityList, rand, chanceToUseCloseCity);
displayTour(population.BestTour, 0, false);
bool foundNewBestTour = false;
TspForm tspform = new TspForm();
int ItterForStop = 0;
int Waiter = 0;
for (generation = 0; generation < maxGenerations; generation++)
{
Waiter += 1;
if (Waiter >= 100)
{
if (TspForm.iteration == 0 || generation >= 50 && generation <= maxGenerations / 100)
{
TspForm.iteration = generation;
}
if (TspForm.iteration != generation)
{
double stop_work = TspForm.iteration - generation / 1.4;
if (stop_work <= 0)
{
ItterForStop += 1;
}
}
if (ItterForStop == iterationForConverge)
{
Halt = true;//Break the algorithm if we found the best tour
}
}
if (Halt)
{
break; // GUI has requested we exit.
}
foundNewBestTour = makeChildren(groupSize, mutation);
if (foundNewBestTour)
{
displayTour(population.BestTour, generation, false);
}
}
displayTour(population.BestTour, generation, true);
}
/// <summary>
/// Starts the TSP algorithm.
/// To stop before all generations are calculated, set <see cref="Halt"/> to true.
/// </summary>
/// <param name="populationSize">Number of random tours to create before starting the algorithm.</param>
/// <param name="maxGenerations">Number of times to perform the crossover operation before stopping.</param>
/// <param name="groupSize">Number of tours to examine in each generation. Top 2 are chosen as the parent tours whose children replace the worst 2 tours in the group.</param>
/// <param name="mutation">Odds that a child tour will be mutated..</param>
/// <param name="seed">Seed for the random number generator.</param>
/// <param name="chanceToUseCloseCity">The odds (out of 100) that a city that is known to be close will be used in any given link.</param>
/// <param name="cityList">List of cities in the tour.</param>
public void Begin(int populationSize, int maxGenerations, int groupSize, int mutation, int seed, int chanceToUseCloseCity, Cities cityList, int Col)
{
rand = new Random(seed);
this.cityList = cityList;
population = new Population();
population.CreateRandomPopulation(populationSize, cityList, rand, chanceToUseCloseCity);
displayTour(population.BestTour, 0, false, Col);
bool foundNewBestTour = false;
int generation;
for (generation = 0; generation < maxGenerations; generation++)
{
if (Halt)
{
break; // GUI has requested we exit.
}
foundNewBestTour = makeChildren(groupSize, mutation);
if (foundNewBestTour)
{
displayTour(population.BestTour, generation, false, Col);
}
}
displayTour(population.BestTour, generation, true, Col);
}
/// <summary>
/// crossover
/// </summary>
public static Tour Crossover(Tour parent1, Tour parent2, Cities cityList, Random rand)
{
Tour child = new Tour(cityList.Count);
int[] cityUsage = new int[cityList.Count];
int city;
int nextCity;
for (city = 0; city < cityList.Count; city++)
{
cityUsage[city] = 0;
}
for (city = 0; city < cityList.Count; city++)
{
if (cityUsage[city] < 2)
{
if (parent1[city].Connection1 == parent2[city].Connection1)
{
nextCity = parent1[city].Connection1;
if (testConnectionValid(child, cityList, cityUsage, city, nextCity))
{
joinCities(child, cityUsage, city, nextCity);
}
}
if (parent1[city].Connection2 == parent2[city].Connection2)
{
nextCity = parent1[city].Connection2;
if (testConnectionValid(child, cityList, cityUsage, city, nextCity))
{
joinCities(child, cityUsage, city, nextCity);
}
}
if (parent1[city].Connection1 == parent2[city].Connection2)
{
nextCity = parent1[city].Connection1;
if (testConnectionValid(child, cityList, cityUsage, city, nextCity))
{
joinCities(child, cityUsage, city, nextCity);
}
}
if (parent1[city].Connection2 == parent2[city].Connection1)
{
nextCity = parent1[city].Connection2;
if (testConnectionValid(child, cityList, cityUsage, city, nextCity))
{
joinCities(child, cityUsage, city, nextCity);
}
}
}
}
for (city = 0; city < cityList.Count; city++)
{
if (cityUsage[city] < 2)
{
if (city % 2 == 1)
{
nextCity = findNextCity(parent1, child, cityList, cityUsage, city);
if (nextCity == -1)
{
nextCity = findNextCity(parent2, child, cityList, cityUsage, city);;
}
}
else
{
nextCity = findNextCity(parent2, child, cityList, cityUsage, city);
if (nextCity == -1)
{
nextCity = findNextCity(parent1, child, cityList, cityUsage, city);
}
}
if (nextCity != -1)
{
joinCities(child, cityUsage, city, nextCity);
if (cityUsage[city] == 1)
{
if (city % 2 != 1)
{
nextCity = findNextCity(parent1, child, cityList, cityUsage, city);
if (nextCity == -1)
{
nextCity = findNextCity(parent2, child, cityList, cityUsage, city);
}
}
else
{
nextCity = findNextCity(parent2, child, cityList, cityUsage, city);
if (nextCity == -1)
{
nextCity = findNextCity(parent1, child, cityList, cityUsage, city);
}
}
if (nextCity != -1)
{
joinCities(child, cityUsage, city, nextCity);
}
}
}
}
}
for (city = 0; city < cityList.Count; city++)
{
while (cityUsage[city] < 2)
{
do
{
nextCity = rand.Next(cityList.Count);
} while (!testConnectionValid(child, cityList, cityUsage, city, nextCity));
joinCities(child, cityUsage, city, nextCity);
}
}
return(child);
}
