[SOLVED] Problems With Larger Number Calulations

[dlebowski]

$ItemTotalPrice=90000
$TaxTotal=900
$CashPremiumDue=4545.00
$CashTotalPaid=0


$GrandTotalNoPremium = ($ItemTotalPrice + $TaxTotal) + $CashPremiumDue;
$AllPaymentTotal = $CashTotalPaid;
$amountdue = number_format(($GrandTotalNoPremium - $AllPaymentTotal), 2, '.', ',');
print "$cym";
print $amountdue;

 

For some reason, $amountdue=90904 instead of 95445.  I do not have this problem when $ItemTotalPrice is a smaller value like $1000.  This works fine.  Has anyone else seen anything like this before?

[nethnet]

The problem is with the decimal in your variable $CashPremiumDue.  When you perform mathematical operations in PHP with variables, by default, those variables are converted to integers if they are not already.  Therefore, since $CashPremiumDue is type float instead of type integer, PHP is recognizing it and treating it the same way it would a string (because of the decimal).  When you add or subtract strings in PHP, only the first character in the "string" is evaluated, so really PHP is recognizing this:

 

<?php

$GrandTotalNoPremium = (90000 + 900) + 4;

?>

 

Obviously that's not what you want, so try something like this instead:

 

<?php

$GrandTotalNoPremium = ($ItemTotalPrice + $TaxTotal) + (int)$CashPremiumDue;

?>

 

Or just drop the .00 if it's always zero.

[dlebowski]

Thanks for the explanation.  This will always be a decimal though because is it a monetary value.  How would I handle that?

[nethnet]

Hrmm, actually, I just ran your original code and it worked fine for me.. no problems.  I don't know why it's adding up different for you.

 

<?php

ini_set(display_errors, TRUE);

$ItemTotalPrice=90000;
$TaxTotal=900;
$CashPremiumDue=4545.00;
$CashTotalPaid=0;


$GrandTotalNoPremium = ($ItemTotalPrice + $TaxTotal) + $CashPremiumDue;
$AllPaymentTotal = $CashTotalPaid;
$amountdue = number_format(($GrandTotalNoPremium - $AllPaymentTotal), 2, '.', ',');
echo $amountdue;

?>

 

And this is what I see on the page:

 

95,445.00

 

Apparently the float vs. integer issue isn't even a problem here...  I guess that just applies to strings.  Try copying what is written above exactly and see if you still get 90,904.00 in your variable.

 

Theo

[dlebowski]

$GrandTotalNoPremium = ($ItemTotalPrice + $absenteebid + $TaxTotal) + $CashPremiumDue;
                                        $AllPaymentTotal = (($CashTotalPaid + $CheckTotalPaid + $CreditTotalPaid) - $CashPremiumPaid);
                                         $amountdue = number_format(($GrandTotalNoPremium - $AllPaymentTotal), 2, '.', ',');
                                        
                                        }
                                    ?>
                                </td>
                              <? print $ItemTotalPrice;
                              ?><br><? print $TaxTotal; ?>
                              <br><? print $CashPremiumDue; ?>
                              <br><? print $CashTotalPaid; ?>
                              <br><? print $absenteebid; ?>
                              <br><? print $CashTotalPaid; ?>
                              <br><? print $CheckTotalPaid; ?>
                              <br><? print $CreditTotalPaid; ?>
                              <br><? print $CashPremiumPaid; ?>
                              <br><? print $amountdue; ?>

 

Here is what I get for the values:

90000

900

4,545.00

0.00

0

0.00

0.00

0.00

0

90,904.00

 

I did create a file called test.php and ran the code in it and it does calculate correctly.  But if I run it within the original script, I get the results above.  I don't understand how this is happening. 

[dlebowski]

I think I may have figured it out.  It doesn't like me to use number_format for both my $CashPremiumDue variable and my $amountdue value.  I was using number_format to generate the $CashPremiumDue value.

 

change from:

$CashPremiumDue=number_format(($GrandTotalNoPremium * $BuyerCashPrem), 2, '.', ',');

 

to:

$CashPremiumDue=round (($GrandTotalNoPremium * $BuyerCashPrem), 2);

 

This appears to have worked although I am off by .01 in a lot of the cases.  I will have to maybe play with the rounding to take care of this.  Why would it not let me use number_format for both $amountdue and $CashPremiumDue?

[PFMaBiSmAd]

The .01 is probably due to the inexact representation of floating point numbers in binary and binary conversion to floating point and back for display (BTW: using a floating point number in a calculation causes that calculation to be done in floating point.)

 

Take a look at the BC (BCD) math functions - http://www.php.net/manual/en/ref.bc.php They essentially work like a calculator would, so the conversion errors to/from binary for floating point numbers are eliminated.

[dlebowski]

I can't tell you how much I appreciate all the help.  bcmul works perfectly.