private SortedDictionary <double, double> GetCashflows(DateTime evaluationDate)
{
SortedDictionary <double, double> cashflows = new SortedDictionary <double, double>();
double yearFrac;
if (IsForward)
{
DateTime prevCashflowDate = IssueDate;
DateTime cashflowDate = IssueDate.AddMonths(CouponGapMonth());
while (cashflowDate < MaturityDate)
{
yearFrac = (cashflowDate - evaluationDate).TotalDays / 365;
if (yearFrac > 0)
{
cashflows.Add(yearFrac, CouponRate * (cashflowDate - prevCashflowDate).TotalDays / 365);
}
prevCashflowDate = cashflowDate;
cashflowDate = cashflowDate.AddMonths(CouponGapMonth());
}
yearFrac = (MaturityDate - evaluationDate).TotalDays / 365;
if (yearFrac > 0)
{
cashflows.Add((MaturityDate - evaluationDate).TotalDays / 365, CouponRate * (MaturityDate - prevCashflowDate).TotalDays / 365);
}
}
else
{
DateTime prevCashflowDate = MaturityDate.AddMonths(-CouponGapMonth());
DateTime cashflowDate = MaturityDate;
while (prevCashflowDate > IssueDate)
{
yearFrac = (cashflowDate - evaluationDate).TotalDays / 365;
if (yearFrac > 0)
{
cashflows.Add(yearFrac, CouponRate * (cashflowDate - prevCashflowDate).TotalDays / 365);
}
cashflowDate = prevCashflowDate;
prevCashflowDate = prevCashflowDate.AddMonths(-CouponGapMonth());
}
yearFrac = (IssueDate - evaluationDate).TotalDays / 365;
if (yearFrac > 0)
{
cashflows.Add((IssueDate - evaluationDate).TotalDays / 365, CouponRate * (IssueDate - cashflowDate).TotalDays / 365);
}
}
// Add principal
if (cashflows.Count != 0)
{
double lastYearFrac = cashflows.Keys.Max();
cashflows[lastYearFrac] += 1;
}
return(cashflows);
}