This model tracks a identical loan modeled as a positive and a negative fund balance. A Timed Event that occurs monthly triggers a Discrete Change set equal to the payment amount (this is calculated using the present value to annuity equation, which is a built-in function in GoldSim).
The payment is applied as a withdrawal if the loan is shown as a positive balance, and a deposit if it is negative. The cumulative amount of payments is tracked in the Cumulative_Payments integrator. Cumulative interest payments are equal to the interest applied to the loan (for loans with negative amortization this would be the minimum of the payments made and the interest charged on the loan). The principal payment is equal to the payments made less the interest paid.
To Open the Model File:
- Start GoldSim
- Click on the File and select Open Example...
- Browse to General Examples --> Financial Examples
- Select the file called Loan.gsm