php 等额本息+等额本金生成公式

/**

* 等额本息

*

* @param month 贷款月数 total 贷款总额 start_time 开始时间

*

* @return arr 期数 本金 利息 总额 剩余还款总额 还款时间

* */

function debx($month,$total,$start_time=0)

{

$arr = array();

$dkm = $month; //贷款月数，就是240个月

$dkTotal = $total; //贷款总额

$surplus = $total; //剩余还款金额

$dknl = 0.0515; //贷款年利率

$emTotal = $dkTotal * $dknl / 12 * pow(1 + $dknl / 12, $dkm) / (pow(1 + $dknl / 12, $dkm) - 1); //每月还款金额

$lxTotal = 0; //总利息

for ($i = 0; $i < $dkm; $i++) {

$lx = $dkTotal * $dknl / 12; //每月还款利息

$em = $emTotal - $lx; //每月还款本金

$surplus = $surplus-$em;

$surplus = $surplus<1?0:$surplus;

//echo "第" . ($i + 1) . "期", " 本金:", $em, " 利息:" . $lx, " 总额:" . $emTotal, "<br />";

$start_time = strtotime('+1 month',$start_time);

$arr[] = array('issue'=>$i+1,'corpus'=>number_format($em,2),'interest'=>number_format($lx,2),'total'=>number_format($emTotal,2),'surplus'=>number_format($surplus,2),'time'=>date('Y-m-d H:i:s',$start_time));

$dkTotal = $dkTotal - $em;

$lxTotal = $lxTotal + $lx;

}

return $arr;

}

/**

* 等额本金

*

* @param month 贷款月数 total 贷款总额 start_time 开始时间

*

* @return arr 期数 本金 利息 总额 剩余还款总额 还款时间

* */

function debj($month,$total,$start_time)

{

$arr = array();

$dkm = $month; //贷款月数，就是240个月

$dkTotal = $total; //贷款总额

$surplus = $total; //剩余还款金额

$dknl = 0.0515; //贷款年利率

$em = $dkTotal / $dkm; //每个月还款本金

$lxTotal = 0; //总利息

for ($i = 0; $i < $dkm; $i++) {

$lx = $dkTotal * $dknl / 12; //每月还款利息

$surplus = $surplus-$em;

$surplus = $surplus<1?0:$surplus;

//echo "第" . ($i + 1) . "期", " 本金:", number_format($em,2), " 利息:" . number_format($lx,2), " 总额:" .number_format(($em + $lx),2), "<br />";

$start_time = strtotime('+1 month',$start_time);

$arr[] = array('issue'=>$i+1,'corpus'=>number_format($em,2),'interest'=>number_format($lx,2),'total'=>number_format($emTotal,2),'surplus'=>number_format($surplus,2),'time'=>date('Y-m-d H:i:s',$start_time));

$dkTotal -= $em;

$lxTotal = $lxTotal + $lx;

}

return $arr;

//echo "总利息:" . $lxTotal;

}