Anonymous

<?php

function payment($apr,$n,$pv,$fv=0.0,$prec=2){
   /* Calculates the monthly payment rouned to the nearest penny
   ** $apr = the annual percentage rate of the loan.
   ** $n  = number of monthly payments (360 for a 30year loan)
   ** $pv    = present value or principal of the loan
   ** $fv  = future value of the loan
   ** $prec = the precision you wish rounded to
   */
   /****************************************\
   ** No Warranty is expressed or implied. **
   *****************************************/

   if ($apr !=0) {
       $alpha = 1/(1+$apr/12);
       $retval =  round($pv * (1 - $alpha) / $alpha /
       (1 - pow($alpha,$n)),$prec) ;
   } else {
       $retval = round($pv / $n, $prec);
   }
   return($retval);

}

echo payment(.1,9,1126.80);
?>