/// <summary>
/// Downloads and processes historical data for given stock symbol.
/// </summary>
/// <param name="symbol">stock symbol, e.g. "msft"</param>
/// <param name="numYearsOfHistory">years of history > 0, e.g. 10</param>
private static void ProcessStockSymbol(string symbol, int numYearsOfHistory)
{
try
{
StockData data = DownloadData.GetHistoricalData(symbol, numYearsOfHistory);
int N = data.Prices.Count;
Task <decimal> T_min = Task.Factory.StartNew <decimal>(() =>
{
return(data.Prices.Min());
}
);
Task <decimal> T_max = Task.Factory.StartNew <decimal>(() =>
{
return(data.Prices.Max());
}
);
Task <decimal> T_avg = Task.Factory.StartNew <decimal>(() =>
{
return(data.Prices.Average());
}
);
Task <double> T_stddev = Task.Factory.StartNew(() =>
{
// Standard deviation:
double sum = 0.0;
decimal l_avg = data.Prices.Average();
foreach (decimal value in data.Prices)
{
sum += Math.Pow(Convert.ToDouble(value - l_avg), 2.0);
}
//
// NOTE: want to test exception handling? Uncomment the following to trigger
// divide-by-zero, and notice you get 2 task exceptions, one from this code
// and one from the continuation task (stderr) that fails because we fail.
//
//int abc = 0;
//int x = 1000 / abc;
return(Math.Sqrt(sum / N));
}
);
Task <double> T_stderr = T_stddev.ContinueWith((antecedent) =>
{
return(antecedent.Result / Math.Sqrt(N));
}
);
//
// Wait and harvest results when done:
//
// NOTE: even though WaitAll is not required for correctness (calls to .Result do
// an implicit .Wait), we use WaitAll for efficiency so that we process tasks in
// order as they finish (versus an arbitrary order implied by calls to .Result).
//
try
{
Task.WaitAll(new Task[] { T_min, T_max, T_avg, T_stddev, T_stderr });
}
catch (AggregateException) // tasking errors:
{
throw; // re-throw, output error messages below:
}
decimal min = T_min.Result;
decimal max = T_max.Result;
decimal avg = T_avg.Result;
double stddev = T_stddev.Result;
double stderr = T_stderr.Result;
//
// Output:
//
Console.WriteLine();
Console.WriteLine("** {0} **", symbol);
Console.WriteLine(" Data source: '{0}'", data.DataSource);
Console.WriteLine(" Data points: {0:#,##0}", N);
Console.WriteLine(" Min price: {0:C}", min);
Console.WriteLine(" Max price: {0:C}", max);
Console.WriteLine(" Avg price: {0:C}", avg);
Console.WriteLine(" Std dev/err: {0:0.000} / {1:0.000}", stddev, stderr);
}
catch (AggregateException ae)
{
Console.WriteLine();
Console.WriteLine("** {0} **", symbol);
ae = ae.Flatten(); // could have a tree of exceptions, so flatten first:
foreach (Exception ex in ae.InnerExceptions)
{
Console.WriteLine("Tasking error: {0}", ex.Message);
}
}
catch (Exception ex)
{
Console.WriteLine();
Console.WriteLine("** {0} **", symbol);
Console.WriteLine("Error: {0}", ex.Message);
}
}
/// <summary>
/// Processes command-line arguments, and outputs to the user.
/// </summary>
///
static void ProcessCmdLineArgs(string[] args, out string version, out string platform, out string symbol, out int numYearsOfHistory)
{
#if DEBUG
version = "debug";
#else
version = "release";
#endif
#if _WIN64
platform = "64-bit";
#elif _WIN32
platform = "32-bit";
#else
platform = "any-cpu";
#endif
symbol = ""; // in case user does not supply:
numYearsOfHistory = 10;
string usage = "Usage: StockHistory.exe [-? /? symbol ]";
if (args.Length > 1)
{
Console.WriteLine("** Error: incorrect number of arguments (found {0}, expecting 1)", args.Length);
Console.WriteLine(usage);
System.Environment.Exit(-1);
}
for (int i = 0; i < args.Length; i++)
{
string arg = args[i];
if (arg == "-?" || arg == "/?")
{
Console.WriteLine(usage);
System.Environment.Exit(-1);
}
else // assume arg is stock symbol:
{
symbol = arg;
}
} //for
if (symbol == "")
{
Console.WriteLine();
Console.Write("Please enter stock symbol (e.g. 'msft'): ");
symbol = Console.ReadLine();
}
symbol = symbol.Trim(); // delete any leading/trailing spaces:
if (symbol == "")
{
Console.WriteLine();
Console.WriteLine("** Error: you must enter a stock symbol, e.g. 'msft'");
Console.WriteLine(usage);
Console.WriteLine();
System.Environment.Exit(-1);
}
Console.WriteLine();
Console.WriteLine("** Parallel-Async Stock History App [{0}, {1}] **", platform, version);
Console.WriteLine(" Stock symbol: {0}", symbol);
Console.WriteLine(" Time period: last {0} years", numYearsOfHistory);
Console.WriteLine(" Internet access? {0}", DownloadData.IsConnectedToInternet());
}
/// <summary>
/// Downloads and processes historical data for given stock symbol.
/// </summary>
/// <param name="symbol">stock symbol, e.g. "msft"</param>
/// <param name="numYearsOfHistory">years of history > 0, e.g. 10</param>
private static void ProcessStockSymbol(string symbol, int numYearsOfHistory)
{
try
{
StockData data = DownloadData.GetHistoricalData(symbol, numYearsOfHistory);
int N = data.Prices.Count;
Task <decimal> t_min = Task.Factory.StartNew(() =>
{
decimal min = data.Prices.Min();
return(min);
});
Task <decimal> t_max = Task.Factory.StartNew(() =>
{
decimal max = data.Prices.Max();
return(max);
});
Task <decimal> t_avg = Task.Factory.StartNew(() =>
{
decimal avg = data.Prices.Average();
return(avg);
});
// Standard deviation:
Task <double> t_stddev = Task.Factory.StartNew(() =>
{
double sum = 0.0;
decimal avg = data.Prices.Average();
foreach (decimal value in data.Prices)
{
sum += Math.Pow(Convert.ToDouble(value - avg), 2.0);
}
double stddev = Math.Sqrt(sum / N);
return(stddev);
});
Task <double> t_stderr = t_stddev.ContinueWith((a) =>
{
// Standard error:
double stderr = a.Result / Math.Sqrt(N);
return(stderr);
});
//
// Output:
//
Task[] tasks = { t_min, t_max, t_avg, t_stddev, t_stderr };
Task.WaitAll(tasks);
Console.WriteLine();
Console.WriteLine("** {0} **", symbol);
Console.WriteLine(" Data source: '{0}'", data.DataSource);
Console.WriteLine(" Data points: {0:#,##0}", N);
Console.WriteLine(" Min price: {0:C}", t_min.Result);
Console.WriteLine(" Max price: {0:C}", t_max.Result);
Console.WriteLine(" Avg price: {0:C}", t_avg.Result);
Console.WriteLine(" Std dev/err: {0:0.000} / {1:0.000}", t_stddev.Result, t_stderr.Result);
}
catch (Exception ex)
{
Console.WriteLine();
Console.WriteLine("** {0} **", symbol);
Console.WriteLine("Error: {0}", ex.Message);
}
}
/// <summary>
/// Downloads and processes historical data for given stock symbol.
/// </summary>
/// <param name="symbol">stock symbol, e.g. "msft"</param>
/// <param name="numYearsOfHistory">years of history > 0, e.g. 10</param>
private static void ProcessStockSymbol(string symbol, int numYearsOfHistory)
{
try
{
StockData data = DownloadData.GetHistoricalData(symbol, numYearsOfHistory);
int N = data.Prices.Count;
decimal min = 0, max = 0, avg = 0;
Task t_min = Task.Run(() =>
{
min = data.Prices.Min();
});
Task t_max = Task.Run(() =>
{
max = data.Prices.Max();
});
Task t_avg = Task.Run(() =>
{
avg = data.Prices.Average();
});
// Standard deviation:
double sum = 0.0;
foreach (decimal value in data.Prices)
{
sum += Math.Pow(Convert.ToDouble(value - avg), 2.0);
}
double stddev = Math.Sqrt(sum / N);
// Standard error:
double stderr = stddev / Math.Sqrt(N);
//
// Output:
//
Console.WriteLine();
Console.WriteLine("** {0} **", symbol);
Console.WriteLine(" Data source: '{0}'", data.DataSource);
Console.WriteLine(" Data points: {0:#,##0}", N);
t_min.Wait();
Console.WriteLine(" Min price: {0:C}", min);
t_max.Wait();
Console.WriteLine(" Max price: {0:C}", max);
t_avg.Wait();
Console.WriteLine(" Avg price: {0:C}", avg);
Console.WriteLine(" Std dev/err: {0:0.000} / {1:0.000}", stddev, stderr);
}
catch (Exception ex)
{
Console.WriteLine();
Console.WriteLine("** {0} **", symbol);
Console.WriteLine("Error: {0}", ex.Message);
}
}
/// <summary>
/// Downloads and processes historical data for given stock symbol.
/// </summary>
/// <param name="symbol">stock symbol, e.g. "msft"</param>
/// <param name="numYearsOfHistory">years of history > 0, e.g. 10</param>
private static void ProcessStockSymbol(string symbol, int numYearsOfHistory)
{
try
{
Task t_error = Task.Factory.StartNew(() =>
{
int i = 10;
int j = 10 / i;
});
StockData data = DownloadData.GetHistoricalData(symbol, numYearsOfHistory);
int N = data.Prices.Count;
Task <decimal> t_min = Task.Factory.StartNew(() =>
{
decimal min = data.Prices.Min();
return(min);
});
Task <decimal> t_max = Task.Factory.StartNew(() =>
{
decimal max = data.Prices.Max();
return(max);
});
Task <decimal> t_avg = Task.Factory.StartNew(() =>
{
decimal avg = data.Prices.Average();
return(avg);
});
// Standard deviation:
Task <double> t_stddev = Task.Factory.StartNew(() =>
{
double sum = 0.0;
decimal l_avg = data.Prices.Average();
foreach (decimal value in data.Prices)
{
sum += Math.Pow(Convert.ToDouble(value - l_avg), 2.0);
}
int i = 10;
int j = 10 / i;
double stddev = Math.Sqrt(sum / N);
return(stddev);
});
// Standard error:
Task <double> t_stderr = t_stddev.ContinueWith((antecedent) =>
{
//t_stddev.Wait();
double stderr = antecedent.Result / Math.Sqrt(N);
return(stderr);
});
//
// Output:
//
//t_min.Wait();
//t_max.Wait();
//t_avg.Wait();
//t_stddev.Wait();
//t_stderr.Wait();
Task[] tasks = { t_min, t_max, t_avg, t_stddev, t_stderr, t_error };
Task.WaitAll(tasks);
//lock (Console.Out)
//{
// Console.WriteLine();
// Console.WriteLine("** {0} **", symbol);
// Console.WriteLine(" Data source: '{0}'", data.DataSource);
// Console.WriteLine(" Data points: {0:#,##0}", N);
// Console.WriteLine(" Min price: {0:C}", t_min.Result);
// Console.WriteLine(" Max price: {0:C}", t_max.Result);
// Console.WriteLine(" Avg price: {0:C}", t_avg.Result);
// Console.WriteLine(" Std dev/err: {0:0.000} / {1:0.000}", t_stddev.Result, t_stderr.Result);
//}
decimal min0 = t_min.Result;
decimal max0 = t_max.Result;
decimal avg0 = t_avg.Result;
double stddev0 = t_stddev.Result;
double stderr0 = t_stderr.Result;
//
// Output:
//
// NOTE: we build a single output string and then write to the console in one op.
// Otherwise, if we output one value at a time, our output might get intermixed
// with the output from another, parallel task. Note that Console class is thread-
// safe, so this works as long as we make only a single call for our output.
//
string output = string.Format("\n** {0} **", symbol);
output = string.Format("{0}\n Data source: '{1}'", output, data.DataSource);
output = string.Format("{0}\n Data points: {1:#,##0}", output, N);
output = string.Format("{0}\n Min price: {1:C}", output, min0);
output = string.Format("{0}\n Max price: {1:C}", output, max0);
output = string.Format("{0}\n Avg price: {1:C}", output, avg0);
output = string.Format("{0}\n Std dev/err: {1:0.000} / {2:0.000}", output, stddev0, stderr0);
Console.WriteLine(output);
}
catch (AggregateException ae)
{
//lock (Console.Out)
//{
// Console.WriteLine();
// ae = ae.Flatten();
// foreach (var ex in ae.InnerExceptions)
// {
// Console.WriteLine("Tasking Error: {0}", ex.Message);
// }
//}
string output = string.Format("\n** {0} **", symbol);
ae = ae.Flatten(); // could have a tree of exceptions, so flatten first:
foreach (Exception ex in ae.InnerExceptions)
{
output = string.Format("{0}\nError: {1}", output, ex.Message);
}
Console.WriteLine(output);
}
catch (Exception ex)
{
//lock (Console.Out)
//{
// Console.WriteLine();
// Console.WriteLine("** {0} **", symbol);
// Console.WriteLine("Error: {0}", ex.Message);
//}
string output = string.Format("\n** {0} **\nError: {1}", symbol, ex.Message);
Console.WriteLine(output);
}
}
/// <summary>
/// Downloads and processes historical data for given stock symbol.
/// </summary>
/// <param name="symbol">stock symbol, e.g. "msft"</param>
/// <param name="numYearsOfHistory">years of history > 0, e.g. 10</param>
private static void ProcessStockSymbol(string symbol, int numYearsOfHistory)
{
try
{
//Create .Net exception
//Task t_error = Task.Factory.StartNew(() =>
//{
// int i = 0;
// int j = 1000 / i;
//});
StockData data = DownloadData.GetHistoricalData(symbol, numYearsOfHistory);
int N = data.Prices.Count;
//decimal min = 0, max = 0, avg = 0;
//Create parallel tasks
Task <decimal> t_Min = Task.Factory.StartNew(() => {
return(data.Prices.Min());
});
//decimal min = t_Min.Result;
Task <decimal> t_Max = Task.Factory.StartNew(() => {
return(data.Prices.Max());
});
Task <decimal> t_Avg = Task.Factory.StartNew(() => {
return(data.Prices.Average());
});
// Standard deviation:
//double sum = 0.0, stddev = 0.0, stderr = 0.0;
Task <double> t_stddev = Task.Factory.StartNew(() => {
//Use local calculated average value instead of waiting for the global value
decimal local_avg = data.Prices.Average();
double sum = 0;
foreach (decimal value in data.Prices)
{
sum += Math.Pow(Convert.ToDouble(value - local_avg), 2.0);
}
return(Math.Sqrt(sum / N));
});
// double stddev = t_stddev.Result;
// Standard error:
//Task<double> t_stderr = Task.Factory.StartNew(() => {
Task <double> t_stderr = t_stddev.ContinueWith((t) => {
//t_stddev.Wait(); //Wait until task is finished
return(t.Result / Math.Sqrt(N));
});
//Array of tasks
Task[] tasks = { t_Min, t_Max, t_Avg, t_stddev, t_stderr };
//Wait for completion of all tasks
Task.WaitAll(tasks);
//
// Output:
//
Console.WriteLine();
Console.WriteLine("** {0} **", symbol);
Console.WriteLine(" Data source: '{0}'", data.DataSource);
Console.WriteLine(" Data points: {0:#,##0}", N);
//t_Min.Wait(); //Wait until task is finished
Console.WriteLine(" Min price: {0:C}", t_Min.Result);
//t_Max.Wait(); //Wait until task is finished
Console.WriteLine(" Max price: {0:C}", t_Max.Result);
//t_Avg.Wait(); //Wait until task is finished
Console.WriteLine(" Avg price: {0:C}", t_Avg.Result);
//t_stderr.Wait(); //Wait until task is finished
Console.WriteLine(" Std dev/err: {0:0.000} / {1:0.000}", t_stddev.Result, t_stderr.Result);
}
catch (AggregateException ae)
{
Console.WriteLine();
//Console.WriteLine("Tasking Error: {0}", ae.InnerException.Message);
//Flatten all exceptions since there could be many of them
ae = ae.Flatten();
foreach (var err in ae.InnerExceptions)
{
Console.WriteLine("Tasking Error: {0}", err.Message);
}
}
catch (Exception ex)
{
Console.WriteLine();
Console.WriteLine("** {0} **", symbol);
Console.WriteLine("Error: {0}", ex.Message);
}
}
