private void compoundInterestToolStripMenuItem_Click(object sender, EventArgs e)
{
CompoundInterest compint = new CompoundInterest();
this.Hide();
compint.Show();
}
private void compoundInterestTSM_Click_1(object sender, EventArgs e)
{
CompoundInterest compint = new CompoundInterest();
this.Hide();
compint.Show();
}
private void button1_Click(object sender, EventArgs e)
{
// Basic variables
// P is the principle
double P;
// r is the amount of money the person wants to deposit
double monthlyContribution;
// n is the total number of years
double numberofYears;
// Interest rate picked by the user
double INTEREST_RATE;
// totalContribution is how much money you would have deposited over time without interest
double totalContribution;
// Total money earned from interest alone
double totalInterest;
// we us little r to determine compound frequency with big r
double R;
double c = 0;
try
{
P = double.Parse(tbInitialDeposit.Text);
// N is total years
numberofYears = double.Parse(tbNumberofYears.Text);
// Get the interest rate / 100
INTEREST_RATE = double.Parse(tbInterestRate.Text) / 100;
// r is how much you want to deposit per month
monthlyContribution = double.Parse(tbmonthlyContribution.Text);
if (cbTimesPerYear.Text == "Annual")
{
lblErrorHandler.Visible = true;
// Number of times to compound
c = 1;
}
else if (cbTimesPerYear.Text == "Bi - Annual")
{
lblErrorHandler.Visible = true;
// Number of times to compound
c = 2;
}
else if (cbTimesPerYear.Text == "Quarterly")
{
lblErrorHandler.Visible = true;
// number of times to compound
c = 4;
}
else if (cbTimesPerYear.Text == "Monthly")
{
lblErrorHandler.Visible = true;
// number of times to compound
c = 12;
}
// THE VARIABLE BELOW IS USED FOR MY OUTPUT, I KEPT THE CODE FOR MY OTHER OUTPUTS
double conversion = CompoundInterest.CpInterestConversion(P, numberofYears, INTEREST_RATE, monthlyContribution, c);
// R is how frequently to deposit per year
R = (monthlyContribution * 6);
// totalContribution is how much money you would have deposited without interest
totalContribution = (R * numberofYears);
// interest rate divided by how often to compound
double ic = INTEREST_RATE / c;
// Body of the left side of the equation
double body = 1 + ic;
// exponent for the left side of the equation
double exponent = numberofYears * c;
// using math.pow to execute the math in the proper order and to save all that in one variable
double Body1 = P * Math.Pow(body, exponent);
// we reuse the math.pow to save the same results again seperate from the first
double body2first = Math.Pow(body, exponent);
// minus one after the exponent is calculated
double subtract = body2first - 1;
// multiply that by the yearly deposit
double body2 = R * subtract;
// put the right half of the equation together, and divide by the demoninator
double rightfinal = body2 / ic;
// add the left and right half of the formula together
double FV = Body1 + rightfinal;
totalInterest = FV - (P + totalContribution);
listBox1.Items.Add("< Calculations for " + numberofYears.ToString() + " years > " + cbTimesPerYear.Text);
listBox1.Items.Add("Predicted Account Value :");
// CONVERSION CLASS IS OUTPUT HERE
listBox1.Items.Add(conversion.ToString("c"));
listBox1.Items.Add(" ");
listBox1.Items.Add("Total Interest earned :");
listBox1.Items.Add(totalInterest.ToString("c"));
listBox1.Items.Add(" ");
listBox1.Items.Add("Total Deposited Money :");
listBox1.Items.Add(totalContribution.ToString("c"));
listBox1.Items.Add(" ");
listBox1.Items.Add("Account Math :");
listBox1.Items.Add(P.ToString("c") + " + " + totalContribution.ToString("c") + " + " + totalInterest.ToString("c"));
// AND HERE
listBox1.Items.Add(" = " + conversion.ToString("c"));
listBox1.Items.Add(" ");
// display text
lblErrorHandler.Text = " ! Success !";
// make sure the text isnt red
lblErrorHandler.ForeColor = System.Drawing.Color.Black;
// change title header color
label6.BackColor = System.Drawing.Color.LightGreen;
}
catch (Exception ex)
{
// Make sure the ERROR Handler is turned on
lblErrorHandler.Visible = true;
lblErrorHandler.ForeColor = System.Drawing.Color.Red;
label6.BackColor = System.Drawing.Color.Red;
lblErrorHandler.Text = "* ERROR *";
// Suggestions for why the code stopped working
MessageBox.Show(ex.Message);
listBox1.Items.Add("< ERROR TIPS >");
listBox1.Items.Add(" ");
listBox1.Items.Add("1. NUMBERS ONLY");
listBox1.Items.Add(" ");
listBox1.Items.Add("2. NONE of the fields can be empty");
listBox1.Items.Add(" ");
listBox1.Items.Add("3. Ensure a Compound frequency");
listBox1.Items.Add(" is selected from the drop down list");
}
}
