credit_calculator simple php function

<?php
/**
 * =================================================================
 * Credit Calculator Function
 * =================================================================
 * Function can calculate your credit payments & percents.
 * Needed a BCMath Arbitrary Precision Mathematics PHP Extension.
 * Correctness: 94.667%
 * =================================================================
 * @author Mars
 * =================================================================
 * @param integer $money - credit sum
 * @param integer $percent - interest on the credit
 * @param integer $months - total months
 * @return array
 */
function credit_calculator ($money, $percent, $months) {

	bcscale(30);
	$debt = $money;
	$_percent = 0.00;
	$_donation = 0.00;
	$result = array();
	$per_month = bcdiv($money,$months);
	
	for ($i = 1; $i < $months + 1; ++$i) {
		$result[$i] = array();
		$x = &$result[$i];
		$x['realpay'] = round($per_month,2);
		$_percent += $x['percent'] = bcadd(bcdiv(bcmul($debt,($percent/100)),12),(M_SQRT1_2/1000000),2);
		$_donation += $x['donation'] = bcadd($per_month,$x['percent'],2);
		$x['owed'] = bcsub($debt,$per_month,2);
		$debt = bcsub($debt,$per_month);
	}
	
	$result['total'] = array(
		'realpay' => $money,
		'percent' => $_percent,
		'donation' => ($_donation < $money) ? $money : $_donation,
		'owed' => 0,
	);
	
	return $result;
}

// example:
print_r(credit_calculator(120000, 16, 12));

практически уверен, не раз делал калькуляторы для бизнесов попроще, так там столько "если", что твоя функция - дай бог 1% от парамтеров, которые рассчитываются в реальном калькуляторе

Array
(
    [1] => Array
        (
            [realpay] => 10000
            [percent] => 1600.00
            [donation] => 11600.00
            [owed] => 110000.00
        )

    [2] => Array
        (
            [realpay] => 10000
            [percent] => 1466.66
            [donation] => 11466.66
            [owed] => 100000.00
        )

    [3] => Array
        (
            [realpay] => 10000
            [percent] => 1333.33
            [donation] => 11333.33
            [owed] => 90000.00
        )

    [4] => Array
        (
            [realpay] => 10000
            [percent] => 1200.00
            [donation] => 11200.00
            [owed] => 80000.00
        )

    [5] => Array
        (
            [realpay] => 10000
            [percent] => 1066.66
            [donation] => 11066.66
            [owed] => 70000.00
        )

    [6] => Array
        (
            [realpay] => 10000
            [percent] => 933.33
            [donation] => 10933.33
            [owed] => 60000.00
        )

    [7] => Array
        (
            [realpay] => 10000
            [percent] => 800.00
            [donation] => 10800.00
            [owed] => 50000.00
        )

    [8] => Array
        (
            [realpay] => 10000
            [percent] => 666.66
            [donation] => 10666.66
            [owed] => 40000.00
        )

    [9] => Array
        (
            [realpay] => 10000
            [percent] => 533.33
            [donation] => 10533.33
            [owed] => 30000.00
        )

    [10] => Array
        (
            [realpay] => 10000
            [percent] => 400.00
            [donation] => 10400.00
            [owed] => 20000.00
        )

    [11] => Array
        (
            [realpay] => 10000
            [percent] => 266.66
            [donation] => 10266.66
            [owed] => 10000.00
        )

    [12] => Array
        (
            [realpay] => 10000
            [percent] => 133.33
            [donation] => 10133.33
            [owed] => 0.00
        )

    [total] => Array
        (
            [realpay] => 120000
            [percent] => 10399.96
            [donation] => 130399.96
            [owed] => 0
        )

)

какие тут могут быть ещё условия?

аннуитетный или дифференцированный график? а какой был превый взнос? а комиссия банка? а на остаток или фиксированная?

Спустя 44 сек.

это так… то что с ходу вспоминается.
дуд таки прав =))

<?php
/**
 * =================================================================
 * Credit Calculator Function
 * =================================================================
 * Function can calculate your credit payments & percents.
 * Needed a BCMath Arbitrary Precision Mathematics PHP Extension.
 * Correctness: 94.667%
 * =================================================================
 * @author Mars
 * =================================================================
 * @param integer $money - credit sum
 * @param integer $percent - interest on the credit
 * @param integer $months - total months
 * @return array
 */
function credit_calculator ($money, $percent, $months) {

	bcscale(30);
	$debt = $money;
	$_percent = 0.00;
	$_donation = 0.00;
	$result = array();
	$per_month = bcdiv($money,$months);
	
	for ($i = 1; $i < $months + 1; ++$i) {
		$result[$i] = array();
		$x = &$result[$i];
		$x['realpay'] = round($per_month,2);
		$_percent += $x['percent'] = bcadd(bcdiv(bcmul($debt,($percent/100)),12),(M_SQRT1_2/1000000),2);
		$_donation += $x['donation'] = bcadd($per_month,$x['percent'],2);
		$x['owed'] = bcsub($debt,$per_month,2);
		$debt = bcsub($debt,$per_month);
	}
	
	$z = ($_donation < $money) ? $money : $_donation;
	
	$result['total'] = array(
		'realpay' => $money,
		'percent' => $_percent,
		'donation' => $z,
		'annuitet' => bcdiv($z, $months, 2),
		'owed' => 0,
	);
	
	return $result;
}