[PD] weird float/add limitation

Alexandre Torres Porres porres at gmail.com
Wed Jan 28 17:47:55 CET 2015


> it's a limitation of 32 bit float

I thought so, but same happens when I use the new Pd Vanilla 64 bits...

what now? :)

2015-01-28 14:41 GMT-02:00 Cyrille Henry <ch at chnry.net>:

>
>
> Le 28/01/2015 17:20, Alexandre Torres Porres a écrit :
>
>  howdy, check the attached patch.
>>
>> 1e+06 + 1 is not equal to 1e+06
>>
>> but 1e+09 + 1 is equal to 1e+09
>>
>> meaning it didn't add 1 to 1e+09! Meaning there's a limit where it stops
>> adding 1 to something.
>>
>> how's that and why?
>>
>
> it's a limitation of 32 bit float.
> since 1 bit is used for the sign, 8 for the exponent, 23 bit are left for
> the significant.
> this mean that you can't have more precision in the significant than 2^24
> -1 (a bit less than 1.7*10^7)
>
> cheers
> c
>
>
>> cheers
>>
>>
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