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Re: percentage discount not calculating properly
- Subject: Re: percentage discount not calculating properly
- From: Chris Travers <..hidden..>
- Date: Wed, 24 Feb 2010 09:04:08 -0800
On Wed, Feb 24, 2010 at 1:13 AM, Luke <..hidden..> wrote:
> On Tue, 23 Feb 2010, Bob Miller wrote:
> See David's message for a supposed fix, but as for what's going on...:
>> One of my clients has recently noticed a slight peculiarity in the
>> percentage discount, and I have been able to verify it.
>> For example, sell 252 items at $1.05 with a 15% discount. By my handy
>> dandy calculator application, 252*1.05*.85=224.91. However, on the
>> invoice, the total calculated is $224.28. It is a small difference,
>> however, it grows when more items are sold. When we put on another
> Your math is not the math which the program does. It does
> 1.05 * 0.85 * 252. That would still be okay, until you show your work.
> 1.05 * 0.85 = 0.8925
> 0.8925 Internal round to 2 decimal places = 0.89
> 0.89 * 252 = 224.28
That's the way this is handled currently.
> This has bugged me to no end. SL had a way to change the precision, but
> LSMB dropped it for reasons I knew not, and provided no workaround for
> this problem [until now].
The dropping was a side-effect of moving to BigFloats and managing
precision. This was necessary to avoid some of the rounding bugs we
found in the code we inherited. Unfortunately I am not sure there is
a straight-forward solution here due to the way precision is tracked.
I am going to try to come up with a bug fix for it shortly, however.