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| <?php
$servername = "localhost";
$username = "root";
$password = "";
$dbname = "payment";
$link=mysqli_connect($servername,$username,$password,$dbname);
// Check connection
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}
if (isset($_POST['button9'])) {
$query = "SELECT * FROM Contrat Limit 1";
if ($result = mysqli_query($link, $query)) {
while ($row = mysqli_fetch_assoc($result)) {
$a= $row["PrixHT"];
$b=$row["Duree"];
$c=$row["VR"];
$d=$row["Redevance"];
ECHO calc_rate($a,$b,$c,$d);
}
/* Libération des résultats */
mysqli_free_result($result);
}
}
/* Fermeture de la connexion */
mysqli_close($link);
function calc_rate($pv, $payno,$RV, $pmt)
{
// check that required values have been supplied
if (empty($pv)) {
echo "<p class='error'>a value for PRINCIPAL is required</p>";
exit;
} // if
if (empty($payno)) {
echo "<p class='error'>a value for NUMBER of PAYMENTS is required</p>";
exit;
} // if
if (empty($pmt)) {
echo "<p class='error'>a value for PAYMENT is required</p>";
exit;
} // if
if (($RV<0)) {
echo "<p class='error'>RV must be > 0 </p>";
exit;
}
// now try and guess the value using the binary chop technique
$GuessHigh = (float)100; // maximum value
$GuessMiddle = (float)2.5; // first guess
$GuessLow = (float)0; // minimum value
$GuessPMT = (float)0; // result of test calculation
do {
// use current value for GuessMiddle as the interest rate,
// and set level of accurracy to 6 decimal places
$GuessPMT = (float)calc_payment($pv, $payno, $GuessMiddle,$RV, 6);
if ($GuessPMT > $pmt) { // guess is too high
$GuessHigh = $GuessMiddle;
$GuessMiddle = $GuessMiddle + $GuessLow;
$GuessMiddle = $GuessMiddle / 2;
} // if
if ($GuessPMT < $pmt) { // guess is too low
$GuessLow = $GuessMiddle;
$GuessMiddle = $GuessMiddle + $GuessHigh;
$GuessMiddle = $GuessMiddle / 2;
} // if
if ($GuessMiddle == $GuessHigh) break;
if ($GuessMiddle == $GuessLow) break;
$int = number_format($GuessMiddle, 9, ".", ""); // round it to 9 decimal places
if ($int == 0) {
echo "<p class='error'>Interest rate has reached zero - calculation error</p>";
exit;
} // if
} while ($GuessPMT !== $pmt);
return $int;
} // calc_rate =======================================================================
function calc_payment($pv, $payno, $int,$RV, $accuracy)
{
// check that required values have been supplied
if (empty($pv)) {
echo "<p class='error'>a value for PRINCIPAL is required</p>";
exit;
} // if
if (empty($payno)) {
echo "<p class='error'>a value for NUMBER of PAYMENTS is required</p>";
exit;
} // if
if (empty($int)) {
echo "<p class='error'>a value for INTEREST RATE is required</p>";
exit;
} // if
if (($RV<0)) {
echo "<p class='error'>RV must be > 0 </p>";
exit;
}
// now do the calculation using this formula:
//******************************************
// INT * ((1 + INT) ** PAYNO)
// PMT = PV * --------------------------
// ((1 + INT) ** PAYNO) - 1
//******************************************
$RV=$RV/pow((1+($int/100)),$payno);
$int = $int / 100; // convert to a percentage
$value1 = $int * pow((1 + $int), $payno);
$value2 = pow((1 + $int), $payno) - 1;
$pmt = ($pv-$RV) * ($value1 / $value2);
// $accuracy specifies the number of decimal places required in the result
$pmt = number_format($pmt, $accuracy, ".", "");
return $pmt;
} // calc_payment ====================================================================
?>
</div>
</body>
</html> |
