/**
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
* You can obtain one at http://mozilla.org/MPL/2.0/.
*/
package org.mifosplatform.portfolio.loanaccount.loanschedule.domain;
public class FinanicalFunctions {
/**
* PMT calculates a fixed monthly payment to be paid by borrower every
* 'period' to ensure loan is paid off in full (with interest).
*
* This monthly payment c depends upon the monthly interest rate r
* (expressed as a fraction, not a percentage, i.e., divide the quoted
* yearly percentage rate by 100 and by 12 to obtain the monthly interest
* rate), the number of monthly payments N called the loan's term, and the
* amount borrowed P known as the loan's principal; c is given by the
* formula:
*
* c = (r / (1 - (1 + r)^-N))P
*
* @param interestRateFraction
* @param numberOfPayments
* @param principal
* @param futureValue
* @param type
*/
public static double pmt(final double interestRateFraction, final double numberOfPayments, final double principal,
final double futureValue, final boolean type) {
double payment = 0;
if (interestRateFraction == 0) {
payment = -1 * (futureValue + principal) / numberOfPayments;
} else {
final double r1 = interestRateFraction + 1;
payment = (futureValue + principal * Math.pow(r1, numberOfPayments)) * interestRateFraction
/ ((type ? r1 : 1) * (1 - Math.pow(r1, numberOfPayments)));
}
return payment;
}
public static int nop(final double interestRateFraction, final double emiAmount, final double principal, final double futureValue,
final boolean type) {
double numberOfPayments = 0;
if (interestRateFraction == 0) {
numberOfPayments = ((Double) (-1 * (futureValue + principal) / emiAmount)).intValue();
} else {
final double r1 = interestRateFraction + 1;
numberOfPayments = (futureValue + principal * Math.pow(r1, emiAmount)) * interestRateFraction
/ ((type ? r1 : 1) * (1 - Math.pow(r1, emiAmount)));
}
return Double.valueOf(numberOfPayments).intValue();
}
}