amortization

(plugins.amortization)

Overview

The amortization plugin in Servoy provides a scripting object for calculating amortizations, managing polynomials, and performing date calculations. It supports creating detailed amortization schedules and solving complex financial computations.

The plugin offers key functionalities, such as creating a new AmortizationCalculation for managing loans and payments and generating amortization schedules. It allows solving for unknown interest rates and calculating residual balances with precision. Polynomial operations include creating, modifying, and evaluating polynomials, finding roots, and computing derivatives. Utilities for date calculations enable determining next dates based on specified periods, supporting various interval types like monthly, quarterly, and annual cycles.

The newCalculation() method creates a customizable amortization instance, while newPolynomial() generates and manipulates polynomial functions for advanced mathematical operations. The nextDate() method provides date interval calculations, useful for managing schedules and understanding payment timelines.

Returned Types

AmortizationCalculation,Polynomial,

Methods Summarized

TypeNameSummary

Creates a new amortization calculation.

Creates a new polynomial which is either 0 or a copy of the specified polynomial.

Creates a new polynomial which is either 0 or a copy of the specified polynomial.

Methods Detailed

newCalculation()

Creates a new amortization calculation.

Returns: AmortizationCalculation

Sample

// Calculate the interest rate for an amortization schedule
// with a loan of 2000 dollars  on January 1, 2005, and 5
// monthly payments of 500 dollars starting on Febuary 28th,
// payments made on the last day of each month.

// Get a new amortization calculation.
var c = plugins.amortization.newCalculation();

// Set the rate to -1 for unknown.
c.addRateChange(-1, new Date(2005, 0, 1));

// Set the compounding period to monthly.
c.addCompoundPeriodChange(12, new Date(2005, 0, 1));

// Add the loan and the payments to the schedule.
c.addLoan(2000, new Date(2005, 0, 1));
var lastDate = null;
var period = 12;
//valid periods are:
//PERIOD_ANNUALY : 1
//PERIOD_BI_ANNUALLY : 2
//PERIOD_DAILY : 365
//PERIOD_FOUR_MONTHLY : 3
//PERIOD_FOUR_WEEKLY : 13
//PERIOD_MONTHLY : 12
//PERIOD_QUARTERLY : 4
//PERIOD_TWO_MONTHLY : 6
//PERIOD_TWO_WEEKLY : 26
//PERIOD_WEEKLY : 52
var number_count = 5;
var startday = 31;
c.addPayment(500, new Date(2005, 1, 28), lastDate, period, number_count, startday);

// Solve for the interest rate.
c.solveForUnknown();
// Get the interest rate and the error in the calculation.
// which should be small (otherwise the calculation did
// not converge for some reason.
var r = c.getUnknown();
var e = c.getError();

// When there are no unknowns you can calculate the
// actual amortization schedule.

// Same as before, use the calculated interest rate.
var c = plugins.amortization.newCalculation();
c.addRateChange(r, new Date(2005, 0, 1));
c.addCompoundPeriodChange(12, new Date(2005, 0, 1));
c.addLoan(2000, new Date(2005, 0, 1));
c.addPayment(500, new Date(2005, 1, 28), null, 12, 5, 31);

// Calculate the actual amortization schedule.
c.calculateAmortizationSchedule();

// Get the amortization schedule (which is a JSDataSet) and
// convert it to html. This way you can put it on a label.
// As a JSDataSet you can just get the values stored in
// the rows and columns to use in your script.
var s = "<html>" + c.getAmortizationSchedule().getAsHTML();

// Get the rest balance, which is the amount left over after
// the amortization schedule. In our case (since we calculated
// the rate to have nothing left, it should amount to no more
// than 1 or 2 cents due to rounding).
var rb = c.getRestBalance();

newPolynomial()

Creates a new polynomial which is either 0 or a copy of the specified polynomial.

Returns: Polynomial

Sample

// create a new polynomial
var p = plugins.amortization.newPolynomial();

// make the polynomial -4*x^2 + 9
p.addTerm(-4, 2); // -4*x^2
p.addTerm(9, 0); // 9

// find the roots
var r1 = p.findRoot(1, 5E-15, 100);
var r2 = p.findRoot(-1, 5E-15, 100);

// get the derivative
q = p.getDerivative();

// show all this information in a dialog
plugins.dialogs.showInfoDialog(
	"polynomial",
	"polynomial: " + p + "\n" +
	"derivative: " + q + "\n" +
	"value in 2: " + p.getValue(2) + "\n" +
	"derivative in 2: " + p.getDerivativeValue(2) + "\n" +
	"root near 1: " + r1 + "\n" +
	"root near -1: " + r2,
	"Ok"
);

// set q to zero
q.setToZero();

// make a copy of p, then add 1 and multiply by 3*x^2
var s = plugins.amortization.newPolynomial(p);
s.addTerm(1, 0); // add 1
s.multiplyByTerm(3, 2); // mulitply by 3*x^2

// make a copy of s and add p
var t = plugins.amortization.newPolynomial(s);
t.addPolynomial(p);

// make a copy of s and multiply by p
var u = plugins.amortization.newPolynomial(s);
u.multiplyByPolynomial(p);

// show all this information in a dialog
plugins.dialogs.showInfoDialog(
	"polynomial",
	"polynomial: " + p + "\n" +
	"polynomial: " + s + "\n" +
	"sum: " + t + "\n" +
	"sum in 2: " + p.getValue(2) + " + " + s.getValue(2) + " = " + t.getValue(2) + "\n" +
	"product: " + u + "\n" +
	"product in 2: " + p.getValue(2) + " * " + s.getValue(2) + " = " + u.getValue(2) + "\n",
	"Ok"
);

newPolynomial(polynomial)

Creates a new polynomial which is either 0 or a copy of the specified polynomial.

Parameters

Returns: Polynomial

Sample

// create a new polynomial
var p = plugins.amortization.newPolynomial();

// make the polynomial -4*x^2 + 9
p.addTerm(-4, 2); // -4*x^2
p.addTerm(9, 0); // 9

// find the roots
var r1 = p.findRoot(1, 5E-15, 100);
var r2 = p.findRoot(-1, 5E-15, 100);

// get the derivative
q = p.getDerivative();

// show all this information in a dialog
plugins.dialogs.showInfoDialog(
	"polynomial",
	"polynomial: " + p + "\n" +
	"derivative: " + q + "\n" +
	"value in 2: " + p.getValue(2) + "\n" +
	"derivative in 2: " + p.getDerivativeValue(2) + "\n" +
	"root near 1: " + r1 + "\n" +
	"root near -1: " + r2,
	"Ok"
);

// set q to zero
q.setToZero();

// make a copy of p, then add 1 and multiply by 3*x^2
var s = plugins.amortization.newPolynomial(p);
s.addTerm(1, 0); // add 1
s.multiplyByTerm(3, 2); // mulitply by 3*x^2

// make a copy of s and add p
var t = plugins.amortization.newPolynomial(s);
t.addPolynomial(p);

// make a copy of s and multiply by p
var u = plugins.amortization.newPolynomial(s);
u.multiplyByPolynomial(p);

// show all this information in a dialog
plugins.dialogs.showInfoDialog(
	"polynomial",
	"polynomial: " + p + "\n" +
	"polynomial: " + s + "\n" +
	"sum: " + t + "\n" +
	"sum in 2: " + p.getValue(2) + " + " + s.getValue(2) + " = " + t.getValue(2) + "\n" +
	"product: " + u + "\n" +
	"product in 2: " + p.getValue(2) + " * " + s.getValue(2) + " = " + u.getValue(2) + "\n",
	"Ok"
);

nextDate(start_date, period, startday)

Parameters

Returns: Date

Sample

//Helper method to get the next date when a period is given;
//valid periods are:
//PERIOD_ANNUALY : 1
//PERIOD_BI_ANNUALLY : 2
//PERIOD_BI_MONTHLY : 365
//PERIOD_FOUR_MONTHLY : 3
//PERIOD_FOUR_WEEKLY : 13
//PERIOD_MONTHLY : 12
//PERIOD_QUARTERLY : 4
//PERIOD_TWO_MONTHLY : 6
//PERIOD_TWO_WEEKLY : 26
//PERIOD_WEEKLY : 52
var a_next_date = plugins.amortization.nextDate(new Date(2005, 1, 28),12,31);

//Sample to calculate intervals between 2 dates;
var startday = 31;
var d_start = new Date(2005, 1, 28)
var d_end = new Date(2005, 11, 20)
var allDates = new Array();
var next = d_start;
//loop over months
while (next.getTime() < d_end.getTime())
{
	next = plugins.amortization.nextDate(next,12,startday)
	allDates[allDates.length] = next;
}
if (allDates.length > 0) allDates.length = allDates.length-1 //clear was one to far
//now check how many days are left
if (allDates.length > 0)
{
	next = allDates[allDates.length-1]
}
else
{
	next = d_start;
}
var days = 0;
//loop over days
while (next.getTime() < d_end.getTime() || next.getDate() < d_end.getDate())
{
	next = plugins.amortization.nextDate(next,365,startday)
	days++;
}
//add total days
allDates[allDates.length] = '(and) '+days+' days'
//make array textual to show
application.output( allDates.join('\n') );

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