simple maths problem

martincrumlish

Hi,

I am working on a bet calculator and at the moment i am working on the maths for a betting feature called a Rule 4. Dunno if anyone on here is familiar with betting so I'll give a brief idea of how it works.

Say there are odds of 2/1 and a rule 4 is in place of 20 cents (from $1) This means we have to multply the 2 from 2/1 by 80 cents (100cents minus 20 cents)

Here is the maths i had for it but its not returning what it should

$odds1 = $odds1 * (1 - $rf1);

$odds1 = 2, $rf1 comes from a form field and it is entered as .20 (so 1 - .20 should be .80, .80 * $odds - 1.6.....but I am getting 1.28.

Any ideas? I am guessing my maths syntax might be messed up but i can't find where.

jamie_kerwick

I have just tried exactly as you typed and got 1.6.
Maybe the form variables aren't being passed properly.
Try printing them out in the page that does the calculations,
( you can do it as html comments  if you don't want to interupt the page's display.)

Jamie

martincrumlish

I think you could be right. if I set the variables in the calculation script rather than the form it gave the correct value.

here is the input field for the value:
<INPUT TYPE=text class=input1 NAME=rf$x SIZE=4> It is inside a for loop incrementing by 1 with a value $x

I checked the source of the form page and saw that the input name is rf1 so it would trigger the if($rf1)

Something strange happened as well. Firsly, I have 2 files, a form.php and a calc.php which is called as an include file and has ll the calculation stuff. I added in some echo's to see the variable values and it gave me 2 sets....1 at the very top of the page and one where the file is included in the HTML. the one at the top gave the correct valus that i entered while the one below gave the incorrect figures I mentioned at the beginning of the post.
here is the rest of that calculationc ode for that bet

	if($rf1){$odds1 = $odds1 * (1 - $rf1);}
	$total = ($odds1/$odds1a * $stake) + $stake;

The script returns $total as your return from the bet. If you stake 1 on a 2/1 bet with a rule 4 of .20 then you should get £2.60 back but it is giving a figure of €2.28

jamie_kerwick

If you are repeating the same section 4 time i would use an array for your variables,

so instead of having $rf1, $rf2, $rf3, $rf4

you have $rf[0], $rf[1], $rf[2], $rf[3],

to make these into variables, name the inputs to rf[].

It would seem that one of your variables involved in the calculation is being changed by either the form.php or calc.php, i would look through all of your code and see where the variables are mentioned.

Or if thats too much, just put echo statements at various points thru your code, the minute the print is wrong, you know where the variable was changed.

martincrumlish

This is very strange. I looked at all the areas where the code variables are manipulated and cant see why they change. i worke dout that somehwere the script is multiplying 1.6 * .8 and that gives 1.28

here is the HTML form (created from this function):

function print_row($bet,$number)
{
	echo "<table class=inputtable>\n<tr>\n<td align=left class=title>\n<b>$bet</b>\n</td>\n<td align=left 
class=title>\n<b>Odds</b>\n</td>\n<td align=left class=deadheat>\n<b>D.H.<font 
size=1>*</font></b>\n</td>\n</tr>";
for( $x = 1; $x < $number; $x++ ) {
	echo "<tr>\n<td align=left class=oddstext>\nSelection 
$x:</td>\n";
	echo "<td align=left class=oddsform>";
	echo "<INPUT TYPE=text class=input1 NAME=odds$x SIZE=4> / <INPUT TYPE=text class=input1 NAME=odds$x"."a 
SIZE=2></td>";
	echo "<td class=deadheatform>";
	echo "<select name=deadheat$x>\n<option></option>\n<option 
value=2>2</option>\n<option value=3>3</option>\n<option 
value=4>4</option>\n<option value=5>5</option>\n<option value=6>6</option>\n</select>";
	echo "</td>\n<td align=left class=oddsform>\n<INPUT 
TYPE=text class=input1 NAME=rf$x SIZE=4>";
	echo "</tr>\n";
	echo "b:".$rf1." - ".$odds1." - ".$odds1a." - ".$stake;
}
echo "<tr>\n<td align=left class=staketext>\nStake:</td>\n<td align=left class=stakeform>\n<INPUT TYPE=text class=input1 NAME=stake SIZE=4>\n</td>\n</tr>\n";
echo "<tr>\n<td align=left colspan=2>\n<INPUT TYPE=submit NAME=submit VALUE=calculate>\n<br>\n<font size=1>(* D.H. = Dead Heat)</font></td>\n</tr>\n</table>\n";
}

Here is the calculation and results page:

<?
if($calc == "Single")
{

if($rf1){$odds1 = $odds1 * (1 - $rf1);}
$total = ($odds1/$odds1a * $stake) + $stake;
if($deadheat1){$total = $total / $deadheat1;}

?>

<!-- results of your bet -->

<table align="left" class="resultstable">
<tr>
<td align="left" class="price">
<b>Price 1</b>
</td>
<td align="left" class="price2">
<?=$odds1."/".$odds1a?>
</td>
</tr>
<tr>
<td align="left" class="stake">
<b>Stake:</b>
</td>
<td class="stake2">
€<?=$stake?>
</td>
</tr>
<?
	}

Those pages are included in a HTML file that passes the value $bet as Single to trigger everything.

Sorry for posting all that code but i cant isolate one problem area to display. Hopefully it will be clearer now you see the code.

martincrumlish

can anyone help with this please? I am stumped

martincrumlish

This post got lost in the forum over the last few days but I am still stuck on this problem. Its driving me mad.

Can someone help me out with it please? I bet its something simple but i cant work out whats goin on.

Thanks in advance,
Martin