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pippin418
03-10-2010, 03:44 AM
I have a script that makes compound interest graphs, but whenever it gets past \$1000 it goes back to one.

1. \$10000 × 0.12 = 1200 + \$10000 = \$11,200.00
2. \$11,200.00 × 0.12 = 1.32 + \$11,200.00 = \$12.32
3. \$12.32 × 0.12 = 1.48 + \$12.32 = \$13.80
4. \$13.80 × 0.12 = 1.66 + \$13.80 = \$15.46

The Php is:

<?php
\$per2 = \$_POST['per'];
\$per = \$per2 * .01;
\$poi = "Percent Of Interest: " . \$per2 . "%<br>";
\$years = \$_POST['years'];
\$prin = \$_POST['prin'];
\$prin2 = round(\$prin, 2);
echo "Principal: " . \$prin2 . "<br>";
echo \$poi;
echo "Years: " . \$years . "<br>";
echo "Principal &times; Percent of Interest = Interest + Principal = New Principal after one year<br>";
?>
<div style="text-decoration: underline">
<?php
\$a = 0;
\$b = 0;
while (\$a < \$years) {
\$b++;
\$val = round(\$prin2 * \$per, 2);
\$val2 = number_format(\$val + \$prin2, 2);
echo \$b . ". \$" . \$prin2 . " &times; " . \$per . " = " . \$val . " + \$" . \$prin2 . " = <b>\$" . \$val2 . "</b><br>";
\$prin2 = \$val2;
\$a++;
}
?>
</div>

And the HTML for the form is:

<html>
<title>Compounding Interest Calculator</title>
<body>
<!-- DONT MIND THIS. DIFFERENT FORM -->
<div style="float: right;">
<form action="stock.php" method="post">
Stock Names/Shares<br>
Symbol: <input type="text" name="s1"> Shares: <input type="text" name="sc1"><br>
Symbol: <input type="text" name="s2"> Shares: <input type="text" name="sc2"><br>
Symbol: <input type="text" name="s3"> Shares: <input type="text" name="sc3"><br>
Symbol: <input type="text" name="s4"> Shares: <input type="text" name="sc4"><br>
Symbol: <input type="text" name="s5"> Shares: <input type="text" name="sc5"><br>
<input type="submit" value="Do it!">
-->
</form>
</div>
<!-- THIS IS THE FORM
<form action="int.php" method="post">
Years:<br><input type="text" name="years"><br>
Principal:<br><input type="text" name="prin"><br>
Interest Percent:<br><input type="text" name="per"><br>
<input type="submit" value="Do it!">
-->
</form>
</body>
</html>
In the actual code there are no <!-- -->'s by the way.

pippin418
03-10-2010, 03:57 AM
Ahh... Nevermind. I changed \$val2 = number_format(\$val + \$prin2, 2); to \$val2 = \$val + \$prin2;

Then I put the number_format() in the echo