public async Task LearnCategoriesAsync()
{
var accounts = await this.db.Accounts.ToArrayAsync();
foreach (var account in accounts)
{
var w = Stopwatch.StartNew();
var expenseCount = this.db.Expenses.Count(ex => ex.AccountId == account.Id);
if (expenseCount < MinimumNumberOfExpensesForPrediction)
{
continue;
}
var expenses = await this.db.Expenses.Where(ex => ex.AccountId == account.Id).ToArrayAsync();
var predictor = new CategoryPredictor();
predictor.Learn(expenses);
this.accountToPredictor.AddOrUpdate(account.Name, predictor, (k, v) => predictor);
w.Stop();
this.log.LogInformation(Events.LearnCategoriesForAccount,
"Learning categories for {AccountName} took {ElapsedMilliseconds}ms ({ExpenseCount} samples)",
account.Name, w.ElapsedMilliseconds, expenseCount);
}
}
public void LearnPredictTest()
{
var trainSet = new[]
{
new Expense(-24.4M, "Haushalt", "Wocheneinkauf"),
new Expense(-23.1M, "Haushalt", "Wocheneinkauf"),
new Expense(-22.4M, "Haushalt", "Wocheneinkauf"),
new Expense(-21.2M, "Haushalt", "Wocheneinkauf"),
new Expense(-500M, "Haushalt", "Elektrogeräte"),
new Expense(-2.5M, "Verpflegung", "Leberkäs"),
};
var predictor = new CategoryPredictor();
predictor.Learn(trainSet);
predictor.Predict(-22.0f, DateTime.Now, DateTime.Now).ShouldBe("Haushalt", "Wocheneinkauf");
predictor.Predict(-600.0f, DateTime.Now, DateTime.Now).ShouldBe("Haushalt", "Elektrogeräte");
predictor.Predict(-2.0f, DateTime.Now, DateTime.Now).ShouldBe("Verpflegung", "Leberkäs");
}