[fpc-devel] Rounding inconsistent (critical)

[Vincent Snijders]

Chris Cheney schreef:
> 
> Date sent:      	Mon, 2 Oct 2006 12:59:45 +0200
> From:           	"Graeme Geldenhuys" <graemeg.lists at gmail.com>
> To:             	"FPC developers' list" <fpc-devel at lists.freepascal.org>
> Subject:        	Re: [fpc-devel] Rounding inconsistent (critical)
> Send reply to:  	FPC developers' list <fpc-devel at lists.freepascal.org>
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> 
>> I also ran the exact example given on the Wikipedia site and I also got errors.
>>
>>   AssertEquals('Failing on 1', '3.02', FormatFloat('0.00', 3.016));
>>   AssertEquals('Failing on 2', '3.01', FormatFloat('0.00', 3.013));
>>   AssertEquals('Failing on 3', '3.02', FormatFloat('0.00', 3.015));
>>   AssertEquals('Failing on 4', '3.04', FormatFloat('0.00', 3.045));
>>   AssertEquals('Failing on 5', '3.05', FormatFloat('0.00', 3.04501));
>>
>>
>> Test 1: Passed
>> Test 2: Passed
>> Test 3: Passed
>> Test 4: Failing on 4 expected: <3.04> but was: <3.05>
>> Test 5: Passed
> 
> See, for example, 
> 
> http://support.microsoft.com/default.aspx?scid=kb;EN-US;q42980
> 
> (there are plenty of other web sites explaining this sort of thing)
> 
> The short version is that very few numbers expressed as a decimal 
> fraction are representable ACCURATELY on a computer.

But 0.125 and 0.375 are representable ACCURATELY on a computer, aren't they?

Vincent