static void MeasureRelativeErrors(Func <Knapsack, KnapsackSolution> solveKnapsack, string directoryPath)
{
if (!Directory.Exists(directoryPath))
{
Console.WriteLine("Directory '{0}' does not exist.", directoryPath);
return;
}
var knapsacksFiles = Directory.EnumerateFiles(directoryPath, "knap_*.dat").ToList();
var relativeErrors = new List <double>();
for (int i = 0; i < knapsacksFiles.Count; i += 2)
{
var bestPrices = LoadBestPricesFromSolutionFile(knapsacksFiles[i + 1]);
var knapsacks = KnapsackLoader.LoadKnapsacks(knapsacksFiles[i], KnapsackLoader.KnapsackPerFile).ToList();
for (int j = 0; j < knapsacks.Count; j++)
{
var result = solveKnapsack(knapsacks[j]);
relativeErrors.Add(ComputeRelativeError(bestPrices[j], result.BestPrice));
}
}
Console.WriteLine($"Average relative error is {relativeErrors.Average()}.");
Console.WriteLine($"Max relative error is {relativeErrors.Max()}.");
}
/* args:
* [0] - a path to a test file
* [1] - a path to a solution file
* [2] - how many times repeat a test
* [3] - whether to save results
* [4 ...] - GA arguments
*/
static void Main(string[] args)
{
var genAlgArgs = ParseArguments(args);
if (genAlgArgs == null)
{
Console.ReadLine();
return;
}
var ga = new GeneticAlgorithm(genAlgArgs);
var results = new List <KnapsackSolution>();
foreach (var knapsack in KnapsackLoader.LoadKnapsacks(args[0], KnapsackLoader.KnapsackPerFile))
{
Console.WriteLine($"---Starting knapsack {knapsack.Id}---");
results.Add(ga.Solve(knapsack));
}
if (bool.Parse(args[3]))
{
SaveSolutions(results);
}
var bestPrices = LoadBestPricesFromSolutionFile(args[1]);
var relativeErrors = results.Select((result, index) => ComputeRelativeError(bestPrices[index], result.BestPrice)).ToList();
Console.WriteLine($"Average relative error is {relativeErrors.Average()}.");
Console.WriteLine($"Max relative error is {relativeErrors.Max()}.");
Console.ReadLine();
}
/* args:
* [0] - a path to directory with testing files
* [1] - how many files to use for testing
* [2] - how many times repeat a single file
* [3] - bf / sbf / heur
* [4] - whether to save results
*/
static void Main(string[] args)
{
var testFiles = LoadTestFiles(args);
if (testFiles == null)
{
Console.ReadLine();
return;
}
int repeatFile = int.Parse(args[2]);
var knapsackSets = testFiles.Select(f => KnapsackLoader.LoadKnapsacks(f, KnapsackLoader.KnapsackPerFile));
Func <Knapsack, KnapsackSolution> solver;
var method = args[3].Trim().ToLower();
if (method == "bf")
{
solver = KnapsackProblemSolver.BruteForce;
}
else if (method == "sbf")
{
solver = KnapsackProblemSolver.SmarterBruteForce;
}
else
{
solver = KnapsackProblemSolver.PriceToWeightRatioHeuristics;
}
bool saveResults = bool.Parse(args[4]);
if (saveResults)
{
var solutions = new List <KnapsackSolution>();
Benchmark(solver, repeatFile, KnapsackLoader.KnapsackPerFile, knapsackSets, solutions);
SaveSolutions(solutions);
}
else
{
Benchmark(solver, repeatFile, KnapsackLoader.KnapsackPerFile, knapsackSets);
}
Console.ReadLine();
}
static void CheckAproximationErrors(string directoryPath, double error)
{
if (!Directory.Exists(directoryPath))
{
Console.WriteLine("Directory '{0}' does not exist.", directoryPath);
return;
}
var knapsacksFiles = Directory.EnumerateFiles(directoryPath, "knap_*.dat").ToList();
var relativeErrors = new List <double>();
for (int i = 0; i < knapsacksFiles.Count; i += 2)
{
var bestPrices = LoadBestPricesFromSolutionFile(knapsacksFiles[i + 1]);
var knapsacks = KnapsackLoader.LoadKnapsacks(knapsacksFiles[i], KnapsackLoader.KnapsackPerFile).ToList();
for (int j = 0; j < knapsacks.Count; j++)
{
var result = KnapsackProblemSolver.DynamicProgrammingByPrice(knapsacks[j].WithPriceFPTAS(error));
int realBestPrice = 0;
for (int k = 0; k < result.Vector.Length; k++)
{
if (result.Vector[k])
{
realBestPrice += knapsacks[j].Items[k].Price;
}
}
relativeErrors.Add(ComputeRelativeError(bestPrices[j], realBestPrice));
}
}
Console.WriteLine();
Console.WriteLine($"For chosen aproximation error {error}: ");
Console.WriteLine($" - average relative error is {relativeErrors.Average()}.");
Console.WriteLine($" - max relative error is {relativeErrors.Max()}.");
}
/* args:
* [0] - a path to directory with testing files
* [1] - how many files to use for testing
* [2] - how many times repeat a single file
* [3] - whether to save results
* [4] - fptas - dynamic programming with aproximation
* [5] - if fptas is used, what error to count with
*/
static void Main(string[] args)
{
var testFiles = LoadTestFiles(args);
if (testFiles == null)
{
Console.ReadLine();
return;
}
var knapsackSets = testFiles.Select(f => KnapsackLoader.LoadKnapsacks(f, KnapsackLoader.KnapsackPerFile));
bool useAprox = args.Length > 4 && args[4].Trim() == "fptas";
if (useAprox)
{
double aproxError = double.Parse(args[5]);
knapsackSets = knapsackSets.Select(set => set.Select(knapsack => knapsack.WithPriceFPTAS(aproxError)));
}
int repeatFile = int.Parse(args[2]);
bool saveResults = bool.Parse(args[3]);
if (saveResults)
{
var solutions = new List <KnapsackSolution>();
Benchmark(KnapsackProblemSolver.DynamicProgrammingByPrice, repeatFile, KnapsackLoader.KnapsackPerFile, knapsackSets, solutions);
SaveSolutions(solutions);
}
else
{
Benchmark(KnapsackProblemSolver.DynamicProgrammingByPrice, repeatFile, KnapsackLoader.KnapsackPerFile, knapsackSets);
}
Console.ReadLine();
}
