> Alain <aze### [at] qwertyorg> wrote:
>> If you have a value of about 1e100, then, the last digit presision would 
>> be about 1e90 to 1e93. This is a serious loss of precision.
> 
>   Note that a double-precision floating point number (which is 64 bits
> in size) has only 53 bits of precision for the base. That's approximately
> 15 digits of precision in base 10. (In other words, if you try to store
> a number with more significant decimal digits than 15 into such a floating
> point value, the lower ones will just be lost.)
> 
>   I assume 1e7 was chose as half of that.
> 
Probably. It looks like a reasonable cut point when you concider that, 
during the calculations, you need to get square roots as well as squares 
and cubes.
Just a multiplication of two floats can double the number of digits.


Alain

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