The VINTSCHED function calculates the interest portion of the payments on a series of variable-rate installment loans that are paid off over a specified number of time periods. VINTSCHED calculates the result for a given time period as the sum of the interest due on each loan that is incurred or outstanding in that period. For each time period, you specify the initial amount of the loans incurred in that time period and the interest rate that will be charged in that time period for each new or outstanding loan.
The result returned by the VINTSCHED function is dimensioned by the union of all the dimensions of loans and rates and the dimension that is used as the time-dimension argument.
VINTSCHED(loans, rates, n, [time-dimension] [STATUS])
A numeric expression that contains the initial amounts of the loans. When loans does not have a time dimension, or when loans is dimensioned by more than one time dimension, the time-dimension argument is required.
A numeric expression that contains the interest rates charged for loans. When rates is a dimensioned variable, it can be dimensioned by any dimension, including a different time dimension. When rates is dimensioned by a time dimension, you specify the interest rate in each time period that will apply to the loans incurred or outstanding in that period. The interest rates are expressed as decimal values; for example, a 5 percent rate is expressed as
A numeric expression that specifies the number of payments required to pay off the loans in the series. The n expression can be dimensioned, but it cannot be dimensioned by the time dimension argument. One payment is made in each time period of the time dimension by which loans is dimensioned or in each time period of the dimension specified in the time-dimension argument. For example, one payment a month is made when loans is dimensioned by
The name of the dimension along which the interest payments are calculated. When loans has a dimension of type of DAY, WEEK, MONTH, QUARTER, or YEAR, the time-dimension argument is optional, unless loans has more than one dimension of these types.
Specifies that VINTSCHED should use the current status list (that is, only the dimension values currently in status in their current status order) when computing the interest portion of the payments. By default VINTSCHED uses the default status list.
When loans has a value other than
NA and the corresponding value of rates is
NA, an error occurs.
VINTSCHED is affected by the NASKIP option. When NASKIP is set to YES (the default), and a loan value is
NA for the affected time period, the result returned by VINTSCHED depends on whether the corresponding interest rate has a value of
NA or a value other than
NA. Table 8-14, "How NASKIP Affects the Results When a Loan or Rate Value is NA for a Given Time Period" illustrates how NASKIP affects the results when a loan or rate value is
NA for a given time period.
|Loan Value||Rate Value||Result when NASKIP = YES||Result when NASKIP = NO|
Interest values (
As an example, suppose a loan expression and a corresponding interest expression both have
NA values for 1997, but both have values other than
NA for succeeding years. When the number of payments is
3, VINTSCHED returns
NA for 1997, 1996, and 1995. For 1997, VINTSCHED returns the interest portion of the payment due for loans incurred in 1995, 1996, and 1997.
The VINTSCHED calculation begins with the first value of the time dimension, regardless of how the status of that dimension may be limited. For example, suppose loans is dimensioned by
year, and the values of
year range from
Yr99. The calculation always begins with
Yr95, even when you limit the status of
year so that it does not include
However, when loans is not dimensioned by the time dimension, the VINTSCHED calculation begins with the first value in the current status of the time dimension. For example, suppose loans is not dimensioned by
year is specified as time-dimension. When the status of
year is limited to
Yr99, the calculation begins with
Yr97 instead of
The following statements create two variables called
DEFINE loans DECIMAL <year> DEFINE rates DECIMAL <year>
Suppose you assign the following values to the variables
YEAR LOANS RATES -------------- ---------- ---------- Yr95 100.00 0.05 Yr96 200.00 0.06 Yr97 300.00 0.07 Yr98 0.00 0.07 Yr99 0.00 0.07
For each year,
loans contains the initial value of the variable-rate loan incurred during that year. For each year, the value of
rates is the interest rate that will be charged for that year on any loans incurred or outstanding in that year.
The following statement specifies that each loan is to be paid off in three payments, calculates the interest portion of the payments on the loans,
REPORT W 20 HEADING 'Payment' VINTSCHED(loans, rates, 3, year)
and produces the following report.
YEAR Payment -------------- -------------------- Yr95 5.00 Yr96 16.10 Yr97 33.06 Yr98 19.43 Yr99 7.48
The interest payment for 1995 is interest on the loan of $100 incurred in 1995, at 5 percent. The interest payment for 1996 is the sum of the interest on the remaining principal of the 1995 loan, plus interest on the loan of $200 incurred in 1996; the interest rate for both loans is 6 percent. The 1997 interest payment is the sum of the interest on the remaining principal of the 1995 loan, interest on the remaining principal of the 1996 loan, and interest on the loan of $300 incurred in 1997; the interest rate for all three loans is 7 percent. Since the 1995 loan is paid off in 1997, the payment for 1998 represents 7 percent interest on the remaining principal of the 1996 and 1997 loans. In 1999, the interest payment is on the remaining principal of the 1997 loan.