static void Main(string[] args)
{
string folder = args.Length != 1 ? @"..\..\Resources\" : args[0];
Console.WriteLine($"{GetTimeStamp()} Files must be in folder {folder}. Use the first argument to specify another folder.");
Console.Write($"{GetTimeStamp()} Enter # of neighbors [50-10000]: ");
int neighbors;
if (!int.TryParse(Console.ReadLine(), out neighbors))
{
Console.Write("Unable to parse input.");
}
else
{
neighbors = neighbors < 50 ? 50 : (neighbors > 10000 ? 10000 : neighbors);
}
Console.WriteLine($"{GetTimeStamp()} neighbors set to: {neighbors}");
Console.WriteLine($"{GetTimeStamp()} Loading data...");
const string moviesFile = "movie_titles.txt";
const string trainingRatingsFile = "TrainingRatings.txt";
const string testRatingsFile = "TestingRatings.txt";
// ReSharper disable once UnusedVariable
MovieData movies = ParseMoviesData(File.ReadAllLines(Path.Combine(folder, moviesFile)));
RatingData trainingRatings = ParseRatingData(File.ReadAllLines(Path.Combine(folder, trainingRatingsFile)));
RatingData testRatings = ParseRatingData(File.ReadAllLines(Path.Combine(folder, testRatingsFile)));
Console.WriteLine($"{GetTimeStamp()} Done.");
DateTime now = DateTime.Now;
long index = 0;
var results = new List <Tuple <double /*predicted*/, double /*actual*/> >();
//Parallel.ForEach(testRatings.GetUsers().TakeWhile(x => Interlocked.Read(ref index) < 5000), userId =>
Parallel.ForEach(testRatings.GetUsers(), userId =>
{
if (Interlocked.Add(ref index, 1) % 100 == 0)
{
PrintProgress(index, now, testRatings.GetUsersCount());
}
var ratings = testRatings.GetUserRatings(userId);
foreach (var movieRating in ratings)
{
double actual = movieRating.Value;
double predicted = trainingRatings.PredictMovieRating(userId, movieRating.Key, neighbors);
lock (results)
results.Add(new Tuple <double, double>(predicted, actual));
}
});
PrintProgress(index, now, testRatings.GetUsersCount());
double mae = CalculateMAE(results);
double mape = CalculateMAPE(results);
double rmsd = CalculateRMSD(results);
Console.WriteLine();
Console.WriteLine($"{GetTimeStamp()} MAE={mae} (Mean Absolute Error)");
Console.WriteLine($"{GetTimeStamp()} MAPE={mape} (Mean Absolute Percentage Error)");
Console.WriteLine($"{GetTimeStamp()} RMSD={rmsd} (Root-mean-square deviation)");
}