/** * YIELDMAT * * Returns the annual yield of a security that pays interest at maturity. * * @param mixed settlement The security's settlement date. * The security's settlement date is the date after the issue date when the security is traded to the buyer. * @param mixed maturity The security's maturity date. * The maturity date is the date when the security expires. * @param mixed issue The security's issue date. * @param int rate The security's interest rate at date of issue. * @param int price The security's price per $100 face value. * @param int basis The type of day count to use. * 0 or omitted US (NASD) 30/360 * 1 Actual/actual * 2 Actual/360 * 3 Actual/365 * 4 European 30/360 * @return float */ public static function YIELDMAT($settlement, $maturity, $issue, $rate, $price, $basis = 0) { $settlement = Functions::flattenSingleValue($settlement); $maturity = Functions::flattenSingleValue($maturity); $issue = Functions::flattenSingleValue($issue); $rate = Functions::flattenSingleValue($rate); $price = Functions::flattenSingleValue($price); $basis = (int) Functions::flattenSingleValue($basis); // Validate if (is_numeric($rate) && is_numeric($price)) { if ($rate <= 0 || $price <= 0) { return Functions::NAN(); } $daysPerYear = self::daysPerYear(DateTime::YEAR($settlement), $basis); if (!is_numeric($daysPerYear)) { return $daysPerYear; } $daysBetweenIssueAndSettlement = DateTime::YEARFRAC($issue, $settlement, $basis); if (!is_numeric($daysBetweenIssueAndSettlement)) { // return date error return $daysBetweenIssueAndSettlement; } $daysBetweenIssueAndSettlement *= $daysPerYear; $daysBetweenIssueAndMaturity = DateTime::YEARFRAC($issue, $maturity, $basis); if (!is_numeric($daysBetweenIssueAndMaturity)) { // return date error return $daysBetweenIssueAndMaturity; } $daysBetweenIssueAndMaturity *= $daysPerYear; $daysBetweenSettlementAndMaturity = DateTime::YEARFRAC($settlement, $maturity, $basis); if (!is_numeric($daysBetweenSettlementAndMaturity)) { // return date error return $daysBetweenSettlementAndMaturity; } $daysBetweenSettlementAndMaturity *= $daysPerYear; return (1 + $daysBetweenIssueAndMaturity / $daysPerYear * $rate - ($price / 100 + $daysBetweenIssueAndSettlement / $daysPerYear * $rate)) / ($price / 100 + $daysBetweenIssueAndSettlement / $daysPerYear * $rate) * ($daysPerYear / $daysBetweenSettlementAndMaturity); } return Functions::VALUE(); }