public double GetEndingBalanceWithMonthly(CalculatorModel calc)
{
double P = calc.InitialAmount;
double r = calc.InterestRate / 100;
double n = calc.CompoundingTimes;
double t = calc.CalcPeriod;
double PMT = (double)calc.MonthlyDeposit;
double depTimes = 12 / n;
double balance = P * Math.Pow((1 + (r / n)), n * t) + (PMT * depTimes * ((Math.Pow(1 + r / n, n * t) - 1) / (r / n)));
balance = Math.Round(balance, 2);
return(balance);
}
public double GetEndingBalance(CalculatorModel calc)
{
double P;
if (calc.MonthlyDeposit != null)
{
P = calc.InitialAmount + (double)calc.MonthlyDeposit * 12;
}
else
{
P = calc.InitialAmount;
}
double r = calc.InterestRate / 100;
double n = calc.CompoundingTimes;
double t = calc.CalcPeriod;
double balance = P * Math.Pow((1 + (r / n)), n * t);
balance = Math.Round(balance, 2);
return(balance);
}
private void SubmitButton_Click(object sender, RoutedEventArgs e)
{
//allows for the compounding functions
Compounding compound = new Compounding();
//clear every time new submission is made
YearlyAmounts = new List <CompoundingDisplayModel>();
YearlyAmountsDataGrid.ItemsSource = null;
bool IsValid = ValidateValues();
//If all of the fields have been entered. If not, nothing will happen
if (IsValid == true)
{
CalculatorModel CalcMod = new CalculatorModel();
CalcMod.InitialAmount = Convert.ToDouble(InitialAmountTextBox.Text); //can't keep it as a string
CalcMod.InterestRate = Convert.ToDouble(InterstRateTextBox.Text);
CalcMod.CalcPeriod = Convert.ToDouble(CompoundingPeriodTextBox.Text);
CalcMod.CompoundingTimes = Convert.ToDouble(CompoundingPerYearTextBox.Text);
if (AmountAddedPerMonTextBox != null && AmountAddedPerMonTextBox.Text != "")
{
CalcMod.MonthlyDeposit = Convert.ToDouble(AmountAddedPerMonTextBox.Text);
}
int years = Convert.ToInt32(CalcMod.CalcPeriod);
double TotalInterest = 0;
double YearInterst = 0;
double PrevYearBalance;
PrevYearBalance = CalcMod.InitialAmount;
for (int i = 1; i <= years; i++)
{
CalcMod.CalcPeriod = i;
double balance;
if (CalcMod.MonthlyDeposit == null)
{
balance = compound.GetEndingBalance(CalcMod);
TotalInterest = balance - CalcMod.InitialAmount;
}
else
{
balance = compound.GetEndingBalanceWithMonthly(CalcMod);
TotalInterest = balance - (CalcMod.InitialAmount + (double)CalcMod?.MonthlyDeposit * 12 * i);
}
YearInterst = PrevYearBalance * CalcMod.InterestRate / 100;
PrevYearBalance = balance;
YearlyAmounts.Add(new CompoundingDisplayModel()
{
Year = i,
Total_Balance = balance,
Total_Interest = TotalInterest,
Year_Interest = YearInterst
});
}
YearlyAmountsDataGrid.Visibility = Visibility.Visible;
YearlyAmountsDataGrid.ItemsSource = YearlyAmounts;
}
}
