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From: szr on 2 Apr 2008 11:53
RedGrittyBrick wrote:
> vivekanand.naik(a)gmail.com wrote:
>> printf("%.32g\n",0.99999999976716936);
>>
>> Perl 5.6.1 output:
>> 0.99999999976716936 --> GOOD
>>
>> Perl 5.8.6 output:
>> 0.99999999976716925 --> ERROR
>>
>>
>> Any reason for such mismatch ?
>> Please let me know how to avoid that or any alternative approach if
>> any.
>>
>
> print Math::BigFloat->new("0.99999999976716936")->bstr();


The version of Math::BigFloat that shipped with 5.6.1, which the op
seems to need, doesn't seem to support ->bstr()

$ perlall -MMath::BigFloat -e 'print
Math::BigFloat->new("0.99999999976716936")->bstr(), "\n";'
<perl5.10.0> 0.99999999976716936
<perl5.8.8 > 0.99999999976716936
<perl5.8.2 > 0.99999999976716936
<perl5.8.0 > 0.99999999976716936
Can't locate object method "bstr" via package "Math::BigFloat" (perhaps
you forgot to load "Math::BigFloat"?) at -e line 1.
<perl5.6.1 >


Perhaps ->ffround(17) could be used instead?

$ perl5.6.1 -MMath::BigFloat -e 'print
Math::BigFloat->new("0.99999999976716936")->ffround(-17), "\n";'
+99999999976716936E-17

You could always update your Math::* modules if you must use 5.6.1,
else, it would better to just install a newer Perl :-)

--
szr


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