/// <summary>
/// Assign every account with monthly balances that fit randomly assigned trend
/// </summary>
public void AssignRandomTrends(Trend goodBalance, Trend badBalance, double variation, Random random)
{
foreach (AccountRecord record in accounts)
{
var account = record.Value;
account.AssignRandomTrend(goodBalance, badBalance, variation, random);
}
}
/// <summary>
/// Assign balance history to vary randomly around randomly assigned trend
/// </summary>
public void AssignRandomTrend(Trend goodBalance, Trend badBalance, double variation, Random random)
{
// choose random trend
const double rateScale = 100.0;
const double balanceScale = 100.0;
double rateMean = (goodBalance.Slope + badBalance.Slope) / 2;
double initialBalanceMean = (goodBalance.Intercept + badBalance.Intercept) / 2;
double rate = rateMean + rateScale * random.NextDouble();
double initialBalance = initialBalanceMean + balanceScale * random.NextDouble();
Trend trend = new Trend { Slope = rate, Intercept = initialBalance };
// balance history is trend plus noise
for (int i = 0; i < Balance.Length; i++)
{
Balance[i] = trend.Predict(i) + variation * random.NextDouble();
}
}
/// <summary>
/// Usage: CreditReview n, optional n is number of customers, use 100,000+ for meaningful timings
/// </summary>
static void Main(string[] args)
{
Console.WriteLine("Credit Review Sample\n");
#if DEBUG
Console.WriteLine("For most accurate timing results, use Release build.\n");
#endif
Random random = new Random(1); // seed 1 makes runs reproducible
// Defaults for data generation, may override some on command line
int months = 36;
int customerCount = 1000000; // for data runs make big enough for significant timing measurements
Trend goodBalance = new Trend { Slope = 0.0, Intercept = 0.0 };
Trend badBalance = new Trend { Slope = -150.0, Intercept = 0.0 };
const double variation = 100.0;
const double overdraft = -1000.0; // Default overdraft limit
// Printed table of results
const int rows = 8;
const int cols = 4;
// Optionally override some defaults on command line
if (args.Length > 0)
customerCount = Int32.Parse(args[0], CultureInfo.CurrentCulture);
if (args.Length > 1)
months = Int32.Parse(args[1], CultureInfo.CurrentCulture);
if (months < 4)
months = 4; // PrintBalance requires at least 4 months
// Force JIT compilation before timing tests
const int fewCustomers = 10;
const int fewMonths = 3;
AccountRepository smallAccounts = new AccountRepository(fewCustomers, fewMonths, overdraft);
smallAccounts.AssignRandomTrends(goodBalance, badBalance, variation, random);
UpdatePredictionsSequential(smallAccounts);
UpdatePredictionsParallel(smallAccounts);
UpdatePredictionsPlinq(smallAccounts);
// Create accounts for timing tests
AccountRepository accounts = new AccountRepository(customerCount, months, overdraft);
accounts.AssignRandomTrends(goodBalance, badBalance, variation, random);
// Print summary of accounts
Console.WriteLine();
Console.WriteLine("{0} customers, {1} months in each account", customerCount, months);
// Execute sequential and parallel versions, print timings
Console.WriteLine();
SampleUtilities.TimedRun(
() => { UpdatePredictionsSequential(accounts); return customerCount; }, "Sequential");
SampleUtilities.TimedRun(
() => { UpdatePredictionsParallel(accounts); return customerCount; }, " Parallel");
SampleUtilities.TimedRun(
() => { UpdatePredictionsPlinq(accounts); return customerCount; }, " PLINQ");
// Print a few accounts including predictions and warnings
accounts.Print(rows, months - cols, cols); // print the last few months
Console.WriteLine("\nRun complete... press enter to finish.");
Console.ReadLine();
}