[Haskell-cafe] Re: Is logBase right?

[Miguel Mitrofanov]

Even in Perl you've got

MigMit:~ MigMit$ perl -e 'printf("%.20f\n",log(125)/log(5))'
3.00000000000000044409

On 22 Aug 2009, at 13:24, Roberto López wrote:

> If 4.0 / 2.0 was 1.9999999999999999999998, it would be ok?
>
> The real value of log10 1000 is 3 (3.0). It can be represented with  
> accuracy
> and it should be.
>
> You get the accuracy value in Perl, but there is the same problem in  
> Python.
> It's a bit discouraging.
>
>
> Eugene Kirpichov wrote:
>
>> What do you consider to be the specification of logBase? Exact
>> floating-point numbers don't exist, so it has to return an
>> approximation. The standard doesn't give any guarantees as to the
>> precision of the approximation. Is a precision of 0.00000000000004  
>> not
>> satisfactory for you?
>>
>
>
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