private static decimal CalculatePredictExchange(string fromCurrency, string toCurrency, DateTime date)
{
var begindate = new DateTime(date.AddMonths(-11).Year, date.AddMonths(-11).Month, 15);
if (date.Day < 15)
{
begindate = new DateTime(date.AddMonths(-12).Year, date.AddMonths(-12).Month, 15);
}
var datas = ExchangeRateService.GetPreviousExchangeData(begindate, fromCurrency, toCurrency);
var calc = Calculator.LinearRegression(datas);
decimal a = calc.X; // intercept
decimal b = calc.Y; // slope
return(a + b * 13);
}
public static bool IsValid(string fromCurrency, string toCurrency)
{
// currency must have three character
var result = true;
if (fromCurrency.Length != 3 || toCurrency.Length != 3)
{
return(result = false);
}
// currency must be in the list currency which take from website
Dictionary <string, string> currencylist = ExchangeRateService.FetchCurrency();
if (!currencylist.Keys.Contains(fromCurrency.ToUpper()) || !currencylist.Keys.Contains(toCurrency.ToUpper()))
{
return(result = false);
}
return(result);
}