Re: Floating Point Approximations.

From: paul c <toledobythesea_at_oohay.ac>
Date: Thu, 29 Mar 2007 00:42:26 GMT
Message-ID: <SXDOh.85072$zU1.83829@pd7urf1no>

Bob Badour wrote:
> paul c wrote:
>

>> Bob Badour wrote:
>>
>>> ...
>>> The epsilon would be 16 times larger for BCD floats.
>>> ie. 5e-7 versus 2^-25
>>
>>
>> Sorry, not hip to epsilon in this context.  Does the above correspond 
>> with 50 millionths versus 32 millionths, or thereabouts?

>
>
> Nope: 0.5 millionths versus 0.0298 millionths scaled by the exponent
> part of the float.
>
> For floating point representations, epsilon is the rounding factor,
> which is half the least significant digit of the mantissa. If I recall
> correctly, a 32-bit BCD float has a 6 decimal digit mantissa with a 2
> decimal digit exponent. A 32-bit binary float has a 24 bit mantissa with
> an 8 bit exponent.

Bloody Hell!

p Received on Wed Mar 28 2007 - 19:42:26 CDT