Library to calculate full loan payments (with dates, periods, principal and interest amounts).
// $paymentAmountCalculator is insance of PaymentAmountCalculatorInterface
// $interestAmountCalculator is instance of InterestAmountCalculatorInterface
$calculator = new PaymentsCalculator($paymentAmountCalculator, $interestAmountCalculator);
$periods = $paymentPeriods; // must be instance of PaymentPeriodsInterface
$principal = 2000;
$interestRate = 20;
$calculationMode = 1 // see PaymentPeriodsInterface for available modes
$payments = $calculator->calculatePayments($periods, $principal, $interestRate, $calculationMode);