public MaxAttemptsResultModel MultiStartHillClimbingMethod(KnapsackModel model, int maxAttemts, bool objDetails, double alpha)
{
var maxAttemptsResultModel = new MaxAttemptsResultModel();
maxAttemptsResultModel.AttemptStatistics = new SortedDictionary <double, double>();
maxAttemptsResultModel.ObjectivesDetails = new List <List <double> >();
for (int attempt = 0; attempt < maxAttemts; attempt++)
{
var result = HillClimbingMethod(model, alpha, objDetails);
if (maxAttemptsResultModel.AttemptStatistics.ContainsKey(result.ResultC))
{
maxAttemptsResultModel.AttemptStatistics[result.ResultC] += 1;
}
else
{
maxAttemptsResultModel.AttemptStatistics.Add(result.ResultC, 1);
}
maxAttemptsResultModel.ObjectivesDetails.Add(result.ObjectiveDetails);
}
maxAttemptsResultModel.Delta = maxAttemptsResultModel.AttemptStatistics.Keys.Last() - maxAttemptsResultModel.AttemptStatistics.Keys.First();
return(maxAttemptsResultModel);
}
public KnapsackModel ReadFile(string path)
{
string[] lines = File.ReadAllLines(path);
KnapsackModel model = new KnapsackModel();
model.N = Convert.ToInt32(lines[0]);
model.C = Convert.ToDouble(lines[lines.Length - 1]);
for (int i = 1; i < lines.Length - 1; i++)
{
var splitedLine = lines[i].Split(new[] { "\t" }, StringSplitOptions.RemoveEmptyEntries);
var tupel = new Tuple <double, double>(Convert.ToDouble(splitedLine[1]), Convert.ToDouble(splitedLine[2]));
if (model.Items == null)
{
model.Items = new List <Tuple <double, double> >()
{
tupel
};
}
else
{
model.Items.Add(tupel);
}
}
return(model);
}
private void defaultFileButton_Click(object sender, EventArgs e)
{
string path = "C:\\Users\\User\\Downloads\\StartTest.in";
FileProcess fileProcess = new FileProcess();
knapsackModel = fileProcess.ReadFile(path);
textBoxN.Text = Convert.ToString(knapsackModel.N);
textBoxTotalC.Text = Convert.ToString(knapsackModel.C);
}
public TotalModel CalculateNewObjective(BitArray X, KnapsackModel model, double alpha)
{
var totalModel = new TotalModel();
for (int i = 0; i < model.N; i++)
{
totalModel.TotalCost += model.Items[i].Item1 * Convert.ToDouble(X[i]);
totalModel.TotalWeight += model.Items[i].Item2 * Convert.ToDouble(X[i]);
}
totalModel.TotalCost = totalModel.TotalCost - alpha * Math.Max(totalModel.TotalWeight - model.C, 0);
return(totalModel);
}
private void findFileButton_Click(object sender, EventArgs e)
{
OpenFileDialog openFileDialog = new OpenFileDialog();
if (openFileDialog.ShowDialog() == System.Windows.Forms.DialogResult.OK)
{
string path = openFileDialog.FileName;
FileProcess fileProcess = new FileProcess();
knapsackModel = fileProcess.ReadFile(path);
textBoxN.Text = Convert.ToString(knapsackModel.N);
textBoxTotalC.Text = Convert.ToString(knapsackModel.C);
}
}
public TotalModel CalculateObjectiveValue(BitArray X, KnapsackModel model)
{
var totalModel = new TotalModel();
for (int i = 0; i < model.N; i++)
{
totalModel.TotalCost += model.Items[i].Item1 * Convert.ToDouble(X[i]);
totalModel.TotalWeight += model.Items[i].Item2 * Convert.ToDouble(X[i]);
if (totalModel.IsModelAppropriate && totalModel.TotalWeight > model.C)
{
totalModel.IsModelAppropriate = false;
}
}
return(totalModel);
}
public void Initialize()
{
// create example Items
var csv = new CsvReader(File.OpenText("knapsackItems.csv"));
csv.Configuration.Delimiter = ";";
csv.Configuration.CultureInfo = new CultureInfo("en-US");
csv.Configuration.RegisterClassMap <KnapsackItemMap>();
_items = csv.GetRecords <KnapsackItem>().ToList();
// maximum weight of all the items
_maxWeight = 10.8;
// Use long names for easier debugging/model understanding.
var config = new Configuration
{
NameHandling = NameHandlingStyle.UniqueLongNames,
ComputeRemovedVariables = true
};
using (var scope = new ModelScope(config))
{
// create a model, based on given data and the model scope
var knapsackModel = new KnapsackModel(_items, _maxWeight);
// Get a solver instance, change your solver
using (var solver = new GurobiSolver())
{
// solve the model
var solution = solver.Solve(knapsackModel.Model);
// import the results back into the model
knapsackModel.Model.VariableCollections.ForEach(vc => vc.SetVariableValues(solution.VariableValues));
foreach (var knapsackItem in _items)
{
knapsackItem.IsPacked = Math.Abs(knapsackModel.y[knapsackItem].Value - 1) < scope.EPSILON;
}
}
}
}
public TotalModel NextObjectiveValue(int[] NFlip, BitArray X, TotalModel prevTotalModel, KnapsackModel model)
{
var totalModel = new TotalModel();
totalModel.TotalCost = prevTotalModel.TotalCost;
totalModel.TotalWeight = prevTotalModel.TotalWeight;
//for each changed bit in start array
foreach (var bitNumber in NFlip)
{
if (bitNumber != 0) //stop because there is no bitNumber elements left
{
//if add element
if (X[bitNumber - 1] == false)
{
totalModel.TotalCost += model.Items[bitNumber - 1].Item1;
totalModel.TotalWeight += model.Items[bitNumber - 1].Item2;
}
//if delete element
else
{
totalModel.TotalCost -= model.Items[bitNumber - 1].Item1;
totalModel.TotalWeight -= model.Items[bitNumber - 1].Item2;
}
}
}
if (totalModel.TotalWeight > model.C)
{
totalModel.IsModelAppropriate = false;
}
return(totalModel);
}
public ResultModel NewFirstAscendHillClimbingMethod(KnapsackModel model, double alpha, bool needObjectiveDetails = false)
{
//selec inital X at random
BitArray X = XInit != null ? XInit : new RandomBitGeneration().GenerateBitArray(model.N);
//initialize settings
var neighborhood = new Neighborhood();
neighborhood.InitNFlip(1, model.N);
var objectiveCalculation = new ObjectiveCalculation();
var xTotalModel = objectiveCalculation.CalculateNewObjective(X, model, alpha);
new FileProcess().WriteFile(X, xTotalModel, "ResultFAHillClimbing");
//for objective Details
var objectiveDetails = new List <double>();
if (needObjectiveDetails)
{
objectiveDetails.Add(xTotalModel.IsModelAppropriate ? xTotalModel.TotalCost : -1);
}
while (!neighborhood.stop)
{
BitArray Y = neighborhood.GetNextNeighborhood(X);
var yTotalModel = objectiveCalculation.CalculateNewObjective(Y, model, alpha);
if (xTotalModel.TotalCost < yTotalModel.TotalCost)
{
X = (BitArray)Y.Clone();
xTotalModel = new TotalModel
{
TotalCost = yTotalModel.TotalCost,
TotalWeight = yTotalModel.TotalWeight,
IsModelAppropriate = yTotalModel.IsModelAppropriate
};
neighborhood.InitNFlip(1, model.N);
new FileProcess().WriteFile(X, xTotalModel, "ResultFAHillClimbing");
if (needObjectiveDetails)
{
objectiveDetails.Add(xTotalModel.IsModelAppropriate ? xTotalModel.TotalCost : -1);
}
}
else
{
neighborhood.MoveNext();
}
}
var resultModel = new ResultModel();
resultModel.ResultC = xTotalModel.TotalCost;
resultModel.ResultW = xTotalModel.TotalWeight;
resultModel.X = (BitArray)X.Clone();
if (needObjectiveDetails)
{
resultModel.ObjectiveDetails = objectiveDetails;
}
return(resultModel);
}
public HillClimbing(KnapsackModel model)
{
XInit = new RandomBitGeneration().GenerateBitArray(model.N);
}
